inside - Ministry for Primary Industries
Transcription
inside - Ministry for Primary Industries
Surveillance MINISTRY FOR PRIMARY INDUSTRIES REPORTING ON NEW ZEALAND’S BIOSECURITY HEALTH STATUS VOLUME 41, NO 2, JUNE 2014 INSIDE: INSIDE: Quarterly report of investigations of suspected exotic diseases Plants and environment investigation report Quarterly report of investigations of suspected exotic marine and freshwater The Emerging Risks System pests and diseases Costs of surveillance trapping Biosecurity risks associated with on-line trading Pest Watch Surveillance ISSN 1176-5305 Surveillance is published on behalf of the Director IDC and Response (Veronica Herrera). The articles in this quarterly report do not necessarily reflect government policy. Editor: Michael Bradstock Technical Editors: Jonathan Watts, Lora Peacock Correspondence and requests to receive Surveillance should be addressed to: Editor Surveillance Ministry for Primary Industries PO Box 2526 Wellington, New Zealand email: surveillance@mpi.govt.nz Reproduction: Articles in Surveillance may be reproduced (except for commercial use or on advertising or promotional material), provided proper acknowledgement is made to the author and Surveillance as source. Publication: Surveillance is published quarterly in March, June, September and December. Distribution via email is free of charge for subscribers in New Zealand and overseas. Editorial services: Words & Pictures, Wellington www.wordpict.co.nz Surveillance is available on the Ministry for Primary Industries website at www.mpi.govt.nz/publications/surveillance/ index.htm Articles from previous issues are also available to subscribers to SciQuest®, a fully indexed and searchable e-library of New Zealand and Australian veterinary and animal science and veterinary continuing education publications, at www.sciquest.org.nz Contents Editorial The Emerging Risks System ANIMALS Reports The MPI Animal General Surveillance Programme 3 5 Quarterly reports: January to March 2014 Quarterly review of diagnostic cases: January to March 2014 9 Quarterly report of investigations of suspected exotic diseases 16 MARINE AND FRESHWATER Quarterly reports: January to March 2014 Quarterly report of investigations of suspected exotic marine and freshwater pests and diseases 20 PLANTS AND ENVIRONMENT Reports Weighing up the costs of surveillance trapping and the likely benefits from avoiding future pest damage Biosecurity risks associated with trading on line and gifts from overseas Quarterly reports: January to March 2014 Plants and environment investigation report PEST WATCH: 15 February – 16 May 2014 21 24 25 26 Surveillance is published as the Ministry for Primary Industries’ authoritative source of information on the ongoing biosecurity surveillance activity and the health status of New Zealand’s animal and plant populations in both terrestrial and aquatic environments. It reports information of interest both locally and internationally and complements New Zealand’s international reporting. 2 surveillance 41 (2) 2014 editorial THE EMERGING RISKS SYSTEM Identifying potential and emerging risks is an important component of effective biosecurity risk management. New information on global pests and diseases is continually being generated. From the thousands of reports, MPI needs to identify and prioritise for action the most significant ones that change the risk profile for New Zealand. Then that information needs to get to the right people for effective early intervention, for example by establishing surveillance systems and communicating emerging risks to stakeholders. While MPI staff have always kept watch on new and emerging pests and diseases, an independent review of import requirements and border processes regarding the introduction of Psa (Pseudomonas syringae pv. actinidiae) into New Zealand recommended that we “renew efforts to centralise the identification and management of emerging risks”. Implementation of the Emerging Risks System (ERS) was a key outcome of the MPI Management Action Plan that constituted the response to that review. The ERS was implemented in August 2012 and focused on identifying significant changes in hosts, distribution or impacts of known organisms, and the emergence of new ones. It covers terrestrial and aquatic organisms of concern to plants, animals and people and is to be extended further into identifying and responding to emerging food safety risks. Staff in the Biosecurity Science and Risk Assessment group actively monitor a small number of important alert sources to identify potential emerging risks. These include Promed, European Plant Protection Organisation alerts, the International Biosecurity Intelligence System and the USDA PestLens, among others. Other MPI staff and stakeholders, particularly in industry and research, are also encouraged to send through any information on emerging risks they think we should know about. Alerts are received by email (emergingrisks@mpi.govt.nz). The systems administrator will log and acknowledge them, then forward the information to the appropriate risk analysis team manager. A “science filter” (i.e. a rapid and documented risk assessment) is then applied that asks questions like: • • • • • • • • Have we looked at this before? What has changed? What is the potential for establishment and impact? Are there viable pathways for establishment? What does the information tell us about the risk? Has it changed substantially? Is it worth considering further? Is it urgent? When this assessment indicates a potential emerging risk, it will be passed to Import Risk Managers for consideration. They will consider the following questions: • Are there any identified hosts or associated products that are eligible for import under a valid Import Health Standard (IHS)? • Are there already any pre-export, border or offshore measures in place to manage the emerging risk? • Does an IHS need to be amended or suspended? • Is it urgent? • Does the information received suggest an urgent change to border procedures? • Are there commodities in transit to New Zealand that we need action on? • Are we already sufficiently prepared? • If not, is the risk great enough to warrant making preparation? • Are there other factors that make action advisable? • Do stakeholders need to be involved in this decision? • What are the communications needs and what audience needs to be targeted? (This includes internal and external parties: exporters, importers, NPPOs, the Minister, MPI officials, etc.) Other MPI managers are alerted when there is a need to consider interventions such as readiness plans and surveillance activities. Forums are also being established to co-ordinate MPI actions in response to some of the more significant and complex emerging risks such the brown marmorated stink bug (Halyomorpha halys). Reports are being generated for frontline staff to raise awareness of some of the more significant risks. Where information does not indicate a significant emerging risk, alerts are closed off and the information filed. The system monitors the flow of information, including actions taken by risk managers where appropriate, with regular reporting across MPI to help us understand our overall response to emerging risks. More than a thousand alerts have been processed by the system since its inception 21 months ago. About a third of these required rapid risk assessment and about 10 percent were passed to Import Risk Managers for assessment. The rest were either closed (when assessment concluded no significant change in risk profile) or an active monitoring search was set up within Google or, more recently, the International Biosecurity Information System (IBIS) administered by the Australian Department of Agriculture. surveillance 41 (2) 2014 3 The new Emerging Risks System substantially improves our ability to identify, communicate and monitor our responses to new and emerging risks but it is just one component of a biosecurity system that manages risks offshore, at the border and within New Zealand. Christine Reed Manager Biosecurity, Science and Risk Assessment Ministry for Primary Industries christine.reed@mpi.govt.nz 4 surveillance 41 (2) 2014 ANIMALS THE MPI ANIMAL GENERAL SURVEILLANCE PROGRAMME The Ministry for Primary Industries (MPI) is the lead organisation in New Zealand’s biosecurity system, and through the administration of the Biosecurity Act 1993 it provides the regulatory requirements necessary to protect the economy, environment and human health from unwanted pests and diseases. The MPI Surveillance and Incursion Investigation (S & II) Group manages New Zealand’s post-border exotic and emerging pest and disease surveillance system, which includes the MPI Animal General Surveillance Programme. This is a passive and general surveillance programme with national coverage that is fundamental to MPI’s surveillance system fulfilling its objectives to: • provide early detection of exotic and emerging diseases across all domestic animals and wildlife in terrestrial, aquatic, and marine environments; • support New Zealand’s statements of freedom from pests or diseases and thus facilitate export trade and the implementation of appropriate border controls to prevent introduction of new unwanted organisms; • document endemic pest and disease occurrence in New Zealand; • support the setting of priorities for endemic disease control programmes; and • support the fulfilment of New Zealand’s international reporting obligations, including to the OIE (World Organisation for Animal Health). The role of general surveillance The Animal General Surveillance Programme is a general surveillance system, i.e. not limited to any particular animal species or pathogen (OIE, 2011). The programme’s primary focus is on sick and dead animals and unusual organisms. After a disease incident, a change in the usual pattern of disease occurrence, or the finding of an unusual organism, it attempts to determine the cause of the illness or death, or to identify the organism. New Zealand operates a comprehensive Animal General Surveillance Programme which, combined with appropriate targeted surveillance programmes, provides for optimal post-border surveillance. An essential part of our national post-border biosecurity system, general surveillance aids the early detection of exotic and emerging pests and diseases. General surveillance also provides evidence to support trade assurances for animal exports and to support sanitary measures on imported animals and animal products that aim to protect New Zealand from unwanted pests and diseases. This is a passive system that relies on the prompt reporting of unusual disease events or organisms and also captures disease occurrence information from sources other than MPI’s surveillance programmes. This contrasts with MPI’s active surveillance programmes, in which veterinary epidemiologists determine, through statistical survey design, the locations and animals to be observed or sampled (Peacock, 2013; Rawdon, 2010). The Animal General Surveillance Programme encourages everyone in New Zealand to be involved in surveillance, and thus attempts to use the greatest possible number of observers – the general public – to maximise the likelihood of detecting new or unusual pests and diseases. This programme is central to New Zealand’s post-border surveillance system because it provides continuous nationwide surveillance across all classes of animals, whether free-living or managed, wild or domestic. Although many biosecurity risks can be identified and effectively managed, it is still not possible to accurately predict future incursions of pests or diseases: which will be the next organism, which species it will affect and where it will first occur. Therefore, for the best chance of detecting a new pest or disease as early as possible, the biosecurity system needs to be vigilant across all susceptible classes of animal nationwide. Moreover, members of the general public may place different values on the various animal species and their associated enterprises and therefore have different surveillance priorities. The Animal General Surveillance Programme provides a base level of surveillance for all animal species, irrespective of competing priorities. A well-managed general passive surveillance system is also recognised as being best for early detection of emerging disease (Thrusfield, 2007; OIE, 2011), a new infection or infestation resulting from the evolution or change of an existing pathogenic agent, or a previously unrecognised pathogenic agent or disease diagnosed for the first time (OIE, 2013a). Over time, general surveillance helps build up a picture of disease occurrence and distribution, enabling changes in the pattern of disease occurrence to be identified by epidemiological analysis. Identification of such changes can facilitate early detection of exotic and emerging infectious diseases (Rawdon, 2007; McFadden 2007). The international expectation is that all countries trading in animals and animal products will have effective disease surveillance systems. New Zealand’s Animal General Surveillance Programme meets the OIE’s international standard for an early detection system for an incursion or emerging disease and includes a functional reporting system for pests and diseases, with adequate coverage of the country’s animal population and all its regions. An early detection system is required before a country can declare itself free from diseases important to trade, including (where applicable and where a country is eligible to do so) declaring freedom from a disease without the need to implement active surveillance targeted to a particular organism (OIE, 2012a–g). surveillance 41 (2) 2014 5 Increasing breadth of potential surveillance cases able to be observed Increasing diagnostic expertise and resources Communication MPI Diagnostic Laboratories Veterinarians, livestock technicians and aquatic specialists General public 0800 Hotline Figure 1: The general surveillance pyramid of scrutiny. Components of New Zealand’s Animal General Surveillance Programme New Zealand’s programme can be divided into two main parts: the Animal Pest and Disease Notification and Investigation System, and scanning surveillance. The Animal Pest and Disease Notification and Investigation system This system, also known as the Passive Surveillance Programme, uses a surveillance network of people in contact with animals, private veterinarians, aquatic specialists, and diagnostic laboratories (Figure 1). It largely relies on awareness and prompt reporting to MPI and is the mechanism by which individuals and organisations outside of MPI can trigger an investigation of a suspected exotic or emerging pest or disease. The extent of MPI investigation and laboratory diagnostics required to either rule out or to identify the presence of suspected exotic or emerging diseases is determined by the circumstances of each case. An investigation may comprise disease-specific confirmatory testing and epidemiological analysis of a report from a laboratory or research institute, or a field investigation of clinical signs reported by a member of the public (e.g. a farmer) or a veterinarian. The system is made up of number of components (Figure 2) that work together to provide effective and efficient early detection: Everyone in New Zealand is being watchful MPI-approved veterinary diagnostic laboratories Communication programme New Zealand animal health laboratory The Notification and Investigation System Legal obligation to report A toll-free pest and disease emergency phone number The MPI pest and disease hotline (0800 809 966) operates 24/7 for anyone in New Zealand to a report a suspected case of an exotic or emerging pest or disease in animals to the National Investigation and Diagnostic Centre (IDC) at Wallaceville, Upper Hutt. Operating since 1998, the hotline receives about 700 calls a year from members of the public, researchers, veterinarians and laboratories. Around 250 of these reports require further investigation, with about two-thirds related to terrestrial and aquatic animal diseases and a third to marine diseases, invasive marine species and pest animals such as snakes. A team of MPI Incursion Investigators Calls to the IDC are transferred to an investigator of the appropriate discipline, who then manages the investigation of the report. Investigators (veterinary epidemiologists and aquatic specialists) may attend a suspected case in the first instance or they may engage an Initial Investigating Veterinarian (IIV). MPI Incursion Investigators participate in a regular programme of training including courses in exotic pest and disease recognition, incursion simulations and providing assistance to other countries during major outbreaks. A New Zealand-wide network of IIVs AsureQuality (AQ) maintains, on behalf of MPI, a team of private and AQ veterinarians who receive biennial training to recognise important exotic pests and diseases (Murray, 2012). IIVs are geographically spread to enable timely attendance anywhere in New Zealand. A MPI Incursion Investigator managing a suspected exotic pest or disease case may ask an IIV to visit the location of the case and carry out an initial assessment. If the IIV cannot rule out exotic disease, the MPI Incursion Investigator will attend to investigate further. A legal obligation to report to MPI Initial investigating veterinarians A MPI pest and disease hotline Trained incursion investigators Figure 2: Components of the animal pest and disease notification system 6 surveillance 41 (2) 2014 Under sections 44 and 46 of the Biosecurity Act 1993, everyone in New Zealand is legally required to report to MPI suspected cases of notifiable organisms and suspected cases of organisms not normally seen in New Zealand. A schedule of notifiable organisms issued under the Biosecurity Act 1993 is maintained for those organisms considered the most significant to animal, plant or human health and trade priorities (Tana et al., 2011). The legal requirement to report suspected cases enables them to be investigated by MPI within the Animal Pest and Disease Notification and Investigation System. The obligation to report extends to industry surveillance programmes, animals slaughtered by primary processors, and testing of animals and germplasm for export. All animals slaughtered by processors in New Zealand undergo pre-slaughter inspection to confirm they are free from clinical signs of disease, and all carcasses undergo post-mortem inspection. New Zealand exports companion animals, livestock, semen and embryos, many of which undergo disease testing to qualify for export or are included in disease monitoring programmes. MPI’s Animal Health Laboratory (AHL) The AHL is an enhanced level 3 physical containment facility based at the IDC Wallaceville, which provides laboratory support for exotic and emerging disease investigations. It undertakes export testing, diagnostic research (including test validation and development) and provides diagnostic support for the S&II group’s targeted surveillance programmes. The laboratory is accredited to ISO 17025 (the general standard for competence in testing and calibration in laboratories) and uses more than 450 diagnostic techniques to test for and identify disease organisms in terrestrial and aquatic animal samples. The laboratory is staffed by 12 technical managers and senior scientists with PhDs in aquatic animal health, biological or veterinary science, and 18 scientists and technicians with an appropriate science degree. The AHL maintains strong national and international links to other laboratories and experts, to facilitate centralised referral of samples for confirmatory testing where in-house diagnostic capability is not available or a second opinion is needed. The AHL also convenes the New Zealand Veterinary Laboratory Network, a group consisting of government organisations, research institutes, commercial laboratories and universities that carry out animal disease diagnostic testing in New Zealand. The network aims “to facilitate communication and exchange of information between the laboratories on topics such as diagnostic methods, quality measures, training needs, and how to continue to improve response capacity within New Zealand” (Anon., 2011). MPI-approved veterinary diagnostic laboratories The eight privately owned veterinary diagnostic testing and pathology laboratories in New Zealand are required under contractual arrangements with MPI to maintain minimum operational and technical quality assurance requirements. These laboratories receive samples taken by veterinary practitioners and researchers from farm animals, companion animals and wildlife for routine sick animal disease investigation, export testing and health screening tests. Contractual obligations with MPI include the requirement for a veterinary pathologist to read, within one working day, the clinical histories on all sick animal cases, to exclude the possibility of exotic disease. If the laboratory suspects an exotic disease after reading the history, or after any subsequent testing, it must notify the IDC the same day. Communication programme MPI has an ongoing communication programme to maintain and increase awareness of its pest and disease hotline and the importance of reporting suspected cases of exotic or emerging disease. To maintain awareness among the approximately 2300 practising veterinarians in New Zealand, articles on exotic disease are published in Surveillance and other veterinary publications and presentations are given at veterinary conferences. MPI veterinarians also provide lectures to veterinary students to ensure they are aware of their responsibility to notify MPI of suspected cases. Presentations, pamphlets and posters at agricultural events and in the media maintain awareness of the pest and disease hotline among the general public. Reports on investigations of suspected cases of exotic disease by MPI Incursion Investigators, and reports on routine sick animal disease investigations from private veterinary laboratories, are published quarterly in Surveillance and are publicly accessible on line. Scanning surveillance The S & II group monitors and analyses trends in pest and disease occurrence, such as frequency, location and affected species. This work includes: • monitoring calls received through the pest and disease hotline relating to sick and dead, wild and domestic animals. Calls are analysed by S&II veterinary epidemiologists (McFadden et al., 2007); • analysing case information and test findings from MPI-approved veterinary diagnostic laboratories. In addition to their obligations listed above, the laboratories are required to provide MPI with monthly reports on all sick animal cases among production livestock, wildlife and (when a zoonotic disease is suspected) companion animals; and • monitoring the cause of death of threatened or critically endangered native species. Under contract to the Department of Conservation, veterinary pathologists at Massey University perform necropsies on these cases. Where appropriate, further diagnostic testing of cases is funded by MPI so that a definitive diagnosis can be made. These and other sources of information on reported disease events and routine disease diagnoses in domestic and wild animals provide a baseline of endemic disease occurrence in New Zealand and enable changes to be detected that may indicate an emerging disease. References Anon. (2011). Animal Health Laboratory. Surveillance 38(3): 9–13. McFadden A, Rawdon T, Bingham P, Loth L (2007) Public reports of avian mortality. Part 2: Spatial and temporal trends. Surveillance 34(3): 14–17. Murray A (2012) Who you gonna call? VetScript 25 (8): 24–25. OIE [World Organisation for Animal Health] (2011) Surveillance and international reporting of diseases in wild animals. Training Programme for OIE National Focal Points for Wildlife, 2nd Cycle Workshop, Version 14. OIE [World Organisation for Animal Health] (2013a) Terrestrial Animal Health Code. Glossary. http://www.oie.int/en/international-standardsetting/terrestrial-code/access-online/. Accessed 3 December 2013. surveillance 41 (2) 2014 7 OIE [World Organisation for Animal Health] (2013b) Terrestrial Animal Health Code. Chapter 3.1. Veterinary Services. http://www.oie.int/en/ international-standard-setting/terrestrial-code/ access-online/. Accessed 3 December 2013. OIE [World Organisation for Animal Health] (2013f) Aquatic Animal Health Code. Aquatic Animal Health Surveillance. http://www.oie.int/ en/international-standard-setting/aquatic-code/ access-online/. Accessed 3 December 2013. OIE [World Organisation for Animal Health] (2013c) Terrestrial Animal Health Code. Chapter 1.4. Animal health surveillance. http:// www.oie.int/en/international-standard-setting/ terrestrial-code/access-online/. Accessed 3 December 2013. OIE [World Organisation for Animal Health] (2013g) Terrestrial Animal Health Code. Chapter 3.2. Evaluation of veterinary services. http:// www.oie.int/en/international-standard-setting/ terrestrial-code/access-online/. Accessed 3 December 2013. OIE [World Organisation for Animal Health] (2013d) Aquatic Animal Health Code. Glossary. http://www.oie.int/en/international-standardsetting/aquatic-code/access-online/. Accessed 3 December 2013. Peacock L, Kittelberger R, Green O, George S (2013) Arbovirus surveillance programme. Surveillance 40(3): 30–31. OIE [World Organisation for Animal Health] (2013e) Aquatic Animal Health Code. Quality of Aquatic Animal Health Services. http:// www.oie.int/en/international-standard-setting/ aquatic-code/access-online/. Accessed 3 December 2013. 8 surveillance 41 (2) 2014 Rawdon T, McFadden A, Stanislawek W, Bingham P (2007) Public reports of avian mortality. Part 1: Risk profiling and investigation. Surveillance 34(3): 10–13. Rawdon TG, Tana T, Thornton RN, McKenzie JS, Stanislawek WL, Kittelberger R, Geale D, Stevenson MA, Gerber N, Cork SC (2010) Surveillance for avian influenza virus subtypes H5 and H7 in chickens and turkeys farmed commercially in New Zealand. New Zealand Veterinary Journal 58(6): 292–298. Tana T, Murray-Cullen J, Johnston C, Lee E (2011) Notifiable organisms. Surveillance 38(2): 20–24. Thrusfield M (2007) Veterinary epidemiology. Third edition. London: Blackwell, 170–171. Toni Tana Senior Adviser Surveillance and Incursion Investigation Ministry for Primary Industries toni.tana@mpi.govt.nz QUARTERLY REPORT OF DIAGNOSTIC CASES: january to march 2014 Gribbles Veterinary Pathology BOVINE A Devon bull calf in Northland was the third calf from a line of 25 heifers to be born with neurological signs. These were characterised by blindness, a fine tremor and inability to stand unassisted; the suckle reflex was retained. A serum bovine viral diarrhoea PCR was negative. Histopathology on the brain showed bilateral white-matter spongiosis that was particularly severe in the basal ganglia, thalamus, hippocampus, brainstem and cerebellar roof regions. An inherited encephalopathy was suspected. Six out of a mob of 70 autumn-calving Northland dairy cows aborted in January. The veterinarian reported no retained fetal membranes and that the cows had been fed only grass. There was a history of new bulls being introduced on to the farm two months prior. A fetus submitted for necropsy had no gross lesions. Histologically there was multifocal necrotising encephalitis and nonsuppurative myocarditis, myositis and hepatitis, consistent with abortion caused by neosporosis. Another Northland dairy herd was suspected to have abortion caused by Neospora caninum after four cows aborted. Bulk milk and serum bovine viral diarrhoea PCR tests on wet and dry stock were negative, and MAT antibody titres to Leptospira Pomona were negative, but all four aborting cows had serum Neospora IFAT antibody titres of 1:2000 or higher. Another seven-year-old aborting Northland dairy cow from a property that had experienced five abortions over three months also had a Neospora IFAT titre of > 1:2000. Culture of fetal stomach contents was negative for bacteria or yeast, and fetal liver, kidney and lung were histologically normal, but there was necrotising placentitis consistent with Neospora caninum abortion. An adult dairy cow from Northland had sunken eyes, was off-colour and had lost condition. A Ziehl-Neelsen-stained faecal smear contained clumps of bacteria resembling Mycobacterium avium ssp. paratuberculosis, and a Johne’s disease serum antibody ELISA test was positive, confirming Johne’s disease. Another case was diagnosed from a serum antibody ELISA test in an adult Auckland dairy cow that had had weight loss, scouring and submandibular oedema. Serum biochemistry in this animal was normal apart from low albumin (15 g/L; normal range 26–35) with concomitant low serum protein (40 g/L; normal range 57–75) and total calcium (1.87 mmol/L; normal range 2–2.6), consistent with a protein-losing enteropathy. Two 6-month-old calves from the Waikato had diarrhoea. Serum GGT levels were normal and a pooled serum bovine viral diarrhoea PCR test was negative. Faecal parasitology revealed no coccidial oocysts, and both serum ferroxidase and whole-blood selenium were normal. Faecal culture was negative for Salmonella spp. but yielded Yersinia pseudotuberculosis, consistent with yersiniosis. Three cows in a Northland dairy herd had grossly suppurative mastitis that always seemed to affect the back right quarter. Cytology confirmed the presence of suppurative inflammation and small rod-shaped bacteria. Culture of a milk sample produced heavy growth of Trueperella (formerly Arcanobacterium) pyogenes, consistent with Trueperella mastitis. In the United Kingdom this bacterium causes summer mastitis in dry cows; outbreaks in summer are linked to high fly populations. In Australasia summer mastitis is sporadic and Trueperella mastitis is mostly seen in lactating cows with teat injuries or sores. Two 3-year-old Friesian cows on a Canterbury dairy farm were presented with vaginal masses. Histologically both cases were typical of papillomavirusinduced fibropapillomas. An autumn-calving 500-cow Canterbury dairy herd had 19 abortions over a twoweek period. Histological examination of the tissues of one fetus revealed typical lesions of Neospora infection. The cow had a high indirect fluorescent antibody titre of > 1:2000 to Neospora caninum. Three 6-month-old crossbred dairy calves in a mob of 150 on a Canterbury farm had become sick and died. One calf was examined and had lesions of toxic renal tubular injury of several days’ duration and the lesions were highly suggestive of acorn toxicity. The calves were on goodquality pasture but further questioning of the owner revealed that they had grazed under some oak trees about 10 days before becoming sick. An Otago dairy farmer found 30 recumbent cows and one dead from a mob of 250 when he went to collect them for early-morning milking. They had been pastured overnight in a paddock full of fathen (Chenopodium album), which is known to induce hypocalcaemia (milk fever). All the recumbent cows recovered after treatment for hypocalcaemia. In Otago and Southland, between late December and early January there were six outbreaks of polioencephalomalacia at a time when pasture was described as lush and growing rapidly. Affected animals were dairy calves, either found dead or recumbent and exhibiting clinical signs of opisthotonus. In most cases only low numbers were affected, but in one case 30 from a mob of 260 dairy calves showed clinical signs and seven died despite thiamine treatment. The diagnosis was confirmed by histopathological examination of the brain. Deaths occurred in a mob of 600 sixmonth-old dairy calves grazing on a Southland farm. By the time the farmer had called in the local veterinarian, three had died and 130 were affected by a marked inspiratory effort and several were coughing. Necropsy of a dead calf showed consolidation of most of both lungs. Histological examination of the affected lung showed changes typical of Histophilus sp. pneumonia, and Histophilus somni was cultured from this lung. In another case, the same organism was cultured from the lung of a single dairy heifer in a mob of 50 grazing irrigated pasture in central Otago. This animal was found dead after showing respiratory signs for eight hours. surveillance 41 (2) 2014 9 Five calves died among a mob of 50 grazing on a Southland grazing block, after showing severe respiratory signs. They died after a short period of respiratory distress characterised by neck extension and open-mouth breathing. Histopathological examination of one lung showed severe alveolar changes with the formation of hyaline membranes, confirming a diagnosis of atypical interstitial pneumonia. There were a large number of outbreaks of enteritis among calves throughout Otago and Southland during the summer. In one outbreak 100 from a mob of 300 calves were affected and at least seven died. Yersinia pseudotuberculosis was isolated from affected animals. Systemic antibiotic treatment appeared to control most outbreaks. There were several small outbreaks of salmonellosis in adult dairy cows in Otago and Southland over this period. Affected cows commonly had high temperatures and bloody diarrhoea. Salmonella Typhimurium was cultured from the faeces. A number of four-to-five-month-old calves were found dead in a large mob on an Otago dairy farm. The first was found dead in the paddock a day before the mob was yarded for drenching. Another died on the way back after drenching and five more were found dead in the paddock over the next two days. Necropsy of a recently dead calf showed free fluid in the abdomen and thorax, and enlarged mesenteric lymph nodes. Culture of the fluid revealed a heavy pure growth of Pasteurella multocida. The paddock was full of weeds, so poor nutrition may have caused the stress that initiated this outbreak. Six out of a herd of 70 autumn-calving Friesian cows from the Auckland region aborted within two months after new bulls were introduced. One fetus was submitted for necropsy and histopathology. It had a crown-to-rump length of 53 cm (corresponding to about 6 months’ gestation) and was mildly autolysed. There were no significant gross lesions. Microscopic examination revealed characteristic foci of necrosis and gliosis in the brain, and infiltrates of lymphocytes, plasma cells and macrophages in the heart, skeletal muscle and liver. These signs were consistent with a diagnosis of neosporosis. 10 surveillance 41 (2) 2014 A large mass was identified in the liver of a cow at post-mortem inspection at a meat works. The cow was an adult dairy cow from a Waikato farm. The mass was multicystic, cream-coloured and measured about 30 x 10 x 10 cm. Hydatids was suspected, so a sample was sent for histology. Microscopic examination revealed an infiltrative multicystic neoplasm composed of epithelial cells showing features of malignancy. A diagnosis of biliary cystadenocarcinoma was made. Veterinary attention was sought for a mob of 40 five-month-old Friesian heifer calves grazing good pasture in the Rangitikei district. One had died suddenly within the previous few days and another was recumbent with profuse, dark diarrhoea. There was a significant “tail end” to the mob. Culture of faeces from the affected calf was negative for Salmonella spp. and Yersinia pseudotuberculosis. There were small numbers of coccidial oocysts in three out of five faecal samples from in-contact calves, and 10 samples contained from 0 to 400 strongyle eggs per gram (mean 165). Histopathology was more revealing, with severe inflammation affecting the distal small intestine and colon, and large numbers of coccidial megaloschizonts, gametocytes and oocysts in the affected areas. This confirmed a diagnosis of coccidiosis, and was a timely reminder that faecal oocyst counts may not accurately reflect the severity of disease if samples are taken before significant shedding of eggs. One out of 100 Friesian heifer calves from a Wanganui dairy farm was found recumbent in the paddock. A number of these calves had previously developed neurological signs that responded to thiamine. The affected calf displayed opisthotonus and respiratory distress. It did not respond to two days of treatment with antibiotics, so was euthanased. Histological examination of the brain revealed laminar cortical necrosis of the cerebral grey matter, with infiltration of affected areas by large numbers of Gitter cells (indicating chronicity). This led to a diagnosis of polioencephalomalacia, which is considered to have been caused by thamine deficiency induced by a change in pasture quality. A three-year-old Jersey cow from Westland became recumbent in the milking shed and died about two hours later. At postmortem a mesenteric torsion was confirmed as the cause of death, but there was also significant liver pathology. Histopathology revealed numerous necrotic tracts filled with haemorrhage and eosinophils throughout the liver, consistent with migration tracts of the immature stages of the liver fluke Fasciola hepatica, and fascioliasis was diagnosed. Three 6-month-old Jersey/Friesian cross dairy heifers from a Taranaki farm were poorly grown and developed diarrhoea. Serum samples tested positive for bovine viral diarrhoea virus (BVDV) by antigen ELISA. Subsequently, serum samples were collected from the other 62 heifers in the mob and tested for BVDV antigen by ELISA. A highly positive result was found in 36, a weakly positive result was found in four, and 22 were negative. Testing of the highly and weakly positive heifers was repeated 28 days later. All the highly positive ones were still highly positive, confirming that they were persistently infected. The four weakly positive heifers returned negative results the second time, indicating that they had only been transiently infected. These results confirmed fetal infection of the heifers with BVDV, and a persistent infection rate of 60 percent (39/65). A group of leased bulls that had been run with the dairy herd during mating were thought to be the source of infection. A three-year-old Friesian cow died while undergoing veterinary treatment on a Rangitikei dairy farm. At necropsy, abscesses were noted in the liver and lung. Examination of tissue samples collected for histopathology revealed thrombi mixed with neutrophils, bacteria and necrotic debris in the arteries of the lung. This suggested that one of the liver abscesses had ruptured into the vena cava and flooded pulmonary blood vessels with purulent material, causing death through these pulmonary emboli. This is known as portocaval syndrome and is thought to be due to rumenitis subsequent to ruminal acidosis, leading to hepatitis and hepatic abscessation. A herd of mixed-age cows in the Rangitikei had been forced to heavily graze a plantain crop infested with redroot (Amaranthus powellii). One cow had been noticed displaying aggression and neurological signs prior to dying. Histopathology revealed severe nephrosis throughout the kidney, consistent with a toxic insult related to ingestion of this nephrotoxic plant. A four-year-old Jersey cow from Taranaki presented with anorexia and pale mucous membranes. Samples sent to the laboratory for a complete blood count did not show anaemia or any significant changes. However, serum biochemistry revealed a marked increase in GDH (2000 U/L; normal range 8–41), a mild increase in GGT (160 U/L; normal range 9–41), and high bilirubin (32 g/L; normal range 0–15). The serum copper concentration was 69 umol/L (normal range 8–18.8), confirming a case of chronic copper toxicity. OVINE A significant “tail end’”of ill-thrifty ewes developed in a line of twotooths purchased during the drought of 2013 and grazed on pasture in the Rangitikei district. A representative ewe was sacrificed for post-mortem examination and diagnostic testing. A Ziehl-Neelsen-stained smear of faeces contained clumps of acid-fast bacilli consistent with Mycobacteria spp. Liver copper and selenium levels were adequate. Histopathology revealed diffuse expansion of the ileal mucosa by myriad epithelioid macrophages containing acid-fast bacilli, confirming a diagnosis of Johne’s disease caused by Mycobacterium avium ssp. paratuberculosis. Twenty Romney lambs aged four to five months died while grazing a red clover sward in the central North Island. They had been given two 5-in-1 clostridial vaccinations and were judged to be in good body condition. Veterinary examination of dying lambs revealed fever, excess salivation, weakness, collapse and central nervous signs. Because some of them had evaded vaccination, a tentative diagnosis of enterotoxaemia was made. Samples were taken from two lambs and processed for histology. In both samples there was severe suppurative meningoencephalitis and ventriculitis. In one there was also vasculitis, and Gram-negative bacteria were present in the brain. Culture of fresh brain was unsuccessful but the histologic changes were considered characteristic of histophilosis. Histophilus somni is the cause of thrombotic meningoencephalitis in cattle, but is also recognised as a cause of meningitis, septicaemia and polyarthritis in sheep. After being mustered for anthelmintic treatment, a mob of 750 lambs in Hawke’s Bay was held overnight in a holding paddock near the yards. Next morning, 40 were recumbent and six were dead. Serum samples collected from three of the recumbent lambs had markedly elevated creatinine phosphokinase concentrations of 43 050, 94 150 and 36 350 IU/L (reference range 132–1573) and aspartate transaminase concentrations of 1301, 2692 and 2544 IU/L (reference range 64–225), indicating severe muscle damage. Histopathology of muscle samples from the dead lambs revealed necrosis of skeletal muscle myofibres, confirming myopathy. A toxic insult was suspected as the likely cause but despite extensive searching no toxic plants were found in the holding paddock, yards or pasture. Previous cases of myopathy in lambs have been associated with staggerweed (Stachys arvensis) ingestion (Vaatstra, 2012). A seven-month-old ewe lamb from Wairarapa shared grazing in an olive orchard with one other lamb. Veterinary attention was sought in early March as she was not eating and was weak and jaundiced. Analysis of a whole-blood sample revealed increased numbers of nucleated red blood cells (31/100 leukocytes; reference level 0) and increased reticulocytes (2 percent; reference level 0), confirming a regenerative anaemia. Serum GLDH was elevated, at 627 IU/L (normal < 40). A few days later the lamb was found dead and at postmortem the liver appeared orange and swollen. Histopathology revealed frequent randomly scattered necrotic hepatocytes and abundant yellow-staining bile pigment in bile ducts. Copper toxicity was suspected and it was found that the orchard was sprayed twice a year, in early spring and late autumn, with a copper spray to control fungal disease. A sample of liver was analysed and revealed the copper concentration was markedly elevated at 4000 µmol/kg (excessive > 2800 µmol/kg) confirming copper toxicity. From January to April, 20 outbreaks of ewe deaths caused by acute salmonellosis on Southland farms were diagnosed at the laboratory. Salmonella Hindmarsh was isolated from the faeces of the dead ewes. Affected ewes showed a sudden onset of recumbency and diarrhoea with green-stained faeces, with death in a few hours. On most farms there were only a small number of deaths at the time when samples were submitted, but one farm had 50 deaths over two weeks. Listeria ivanovii was isolated from the faeces of one of two new rams that died after two days of severe diarrhoea that occurred two weeks after they arrived on a Southland farm. Home-bred rams that they had been mixed with were unaffected. This Listeria species is usually associated with abortions in ewes. Salmonella cultures were negative. Fifteen out of a mob of 400 twotooth ewes on an Otago sheep farm were found recumbent or dead over several days, a week after yarding. The recumbent ewes showed a marked nasal discharge and were found dead a few hours later. Necropsy of a ewe that had been dead for several hours revealed completely consolidated, congested lungs covered with a thick mat of fibrin. Mannheimia haemolytica was cultured and histopathological examination of lung sections showed a severe fibrinous pleuropneumonia. A four-month-old ram lamb from the Waikato died and at necropsy was found to have bilateral cranioventral pneumonia. Microscopic examination of lung sections revealed chronic active necrosuppurative pneumonia with short rod-shaped bacteria. Culture of fresh lung produced a heavy growth of Trueperella (formerly Arcanobacterium) pyogenes, consistent with Truperella pneumonia. CAPRINE A two-year-old nanny goat from a flock in the Waikato lost weight over a period of weeks and was euthanased. There were multiple 10–25-mm white encapsulated nodules scattered throughout the liver and lungs. Microscopically the lesions consisted of areas of central caseous necrosis within which ghosted macrophages containing fine basophilic cocci were seen. Surrounding these necrotic areas were epitheloid macrophages admixed with low numbers of lymphocytes, plasma cells and neutrophils, blending peripherally into concentric fibrosis. The macrophages often contained large numbers of fine basophilic cocci, either dispersed through the cytoplasm or within clear cytoplasmic vacuoles. Examination of Gram-stained surveillance 41 (2) 2014 11 sections enabled the bacteria to be characterised as small pleomorphic Gram-positive cocci, confirming a diagnosis of Rhodococcus equi infection. R. equi is a soil-borne organism often associated with respiratory and enteric infections in foals. Occasional infections are diagnosed in cattle, cats and goats (Davis et al., 1999). Underlying factors such as enteric parasitism, CAEV infection and marginal nutrition during pregnancy and lactation may predispose goats to disseminated disease. Two recently weaned goat kids became weak and died on a Bay of Plenty farm. The property had a history of drenching the kids at eight-weekly intervals with a combination anthelmintic containing levamisole HCl, abamectin and oxfendazole. The next treatment was due but had not yet been given. Gastrointestinal parasite faecal egg counts on the two dead kids were 19 000 and 17 600 eggs per gram, confirming severe parasitism. A three-year-old Saanen goat from the Waikato had kidded in July and then progressively lost weight until February despite having high-quality feed. Serum biochemistry was normal and faecal parasitology was negative for Nematodirus eggs but revealed 1000 strongyle eggs/gram, and a serum caprine arthritis and encephalitis (CAE) virus ELISA was positive, suggesting nematodiasis and infection with CAE virus. Follow-up herd serology a month later confirmed that seven out of 10 goats tested were positive for CAEV infection. CANINE AND FELINE A nine-week-old Huntaway pup from Southland was one of several dying in a litter affected by diarrhoea and depression. The property had a history of similar outbreaks of disease in litters, despite supportive care. The puppies and their dam had been routinely vaccinated and the kennels were routinely disinfected. A post-mortem examination identified no gross lesions apart from subcutaneous oedema consistent with subcutaneous fluid administration, and histopathology of a wide range of organs showed no significant findings. No Campylobacter or Salmonella organisms were isolated on faecal culture, and faecal parasitology was negative but a faecal parvovirus antigen ELISA test was positive (thought to be due to prior vaccination). Faecal antigen ELISA 12 surveillance 41 (2) 2014 tests were negative for Cryptosporidium spp. but positive for Giardia spp., suggesting that giardiasis was the underlying problem. An eight-week-old crossbred puppy from Auckland had dysentery. Faecal antigen ELISA tests were negative for Cryptosporidium and Giardia spp. Faecal parasitology identified 1000 ascarid eggs/ gram and faecal culture was positive for Campylobacter spp., indicating that the puppy had combined nematodiasis and campylobacteriosis. A five-month-old Cavalier King Charles puppy from Auckland had diarrhoea for more than a week. Faecal parasitology was negative; faecal culture was negative for Salmonella spp. but yielded a growth of Campylobacter spp. Faecal antigen ELISA tests were negative for Cryptosporidium but positive for Giardia spp., consistent with combined giardiasis and campylobacteriosis. An eight-week-old crossbred puppy from Auckland had large-bowel diarrhoea for two weeks. Signs persisted despite a range of treatments including fenbendazole, metronidazole/spiramycin and Scourban. Faecal culture was negative for Salmonella and Campylobacter spp., but faecal parasitology identified 300 ascarid eggs/gram. Faecal antigen ELISA tests were negative for Giardia but positive for Cryptosporidium spp., supporting a diagnosis of combined nematodiasis and cryptosporidiosis. A two-year-old Bengal cat from Northland had a history of altered behaviour, weight loss, diarrhoea and prolapsed third eyelids. The intestines contained gas on palpation and the anus was inflamed. Faecal antigen ELISA tests for Giardia spp were positive but the cat tested negative by ELISA for Cryptosporidium. Faecal parasitology and faecal culture for Salmonella and Campylobacter spp. were all negative. A nine-week-old Burmese kitten from Northland was anorexic and not thriving. Faecal antigen ELISA tests were positive for Giardia spp., and faecal culture yielded a growth of Campylobacter spp., consistent with combined giardiasis and campylobacteriosis. Faecal parasitology and faecal culture for Salmonella spp. were both negative. A two-month-old Domestic Shorthaired cat from Auckland had diarrhoea. Faecal parasitology was negative for nematode eggs or coccidial oocysts, and faecal antigen ELISA tests were negative for Giardia but positive for Cryptosporidium spp., supporting a diagnosis of cryptosporidiosis. A middle-aged Huntaway dog from Otago developed a purulent lesion on a front foot. About a week later the farmer noticed that although it could still walk around and eat, it had a stiff neck, pricked ears, exophthalmos and protruding third eyelids. Tetanus was suspected and treatment with high doses penicillin was instituted. After seven to 10 days of treatment the dog had not improved, so corticosteroid therapy was also instituted. This produced a more rapid improvement, so that after a further two weeks the dog was nearly back to normal. A two-year-old male neutered Staffordshire Bull Terrier from the Waikato presented with a three-week history of diarrhoea and weight loss. Ultrasound examination suggested disseminated disease throughout the pancreas, small intestine and kidneys, so exploratory laparotomy was performed. Grossly there were multiple discrete 2–5-mm creamcoloured nodules throughout the intestinal tract, associated lymph nodes, pancreas and kidneys. Biopsy samples were taken. Histologically the nodules were composed of pyogranulomatous inflammation punctuated by moderate numbers of 4–8-µm spherical yeast cells surrounded by thick, clear capsules. The cells often occurred in clusters within clear spaces and displayed narrow-based budding. These findings were consistent with a diagnosis of disseminated cryptococcosis. This is an uncommon diagnosis in dogs but is reasonably well recognised as a respiratory infection in cats, and may be fatal in immunocompromised humans. The infective yeast is inhaled or inoculated from environmental sources such as soil or bird droppings (especially pigeons). The dog was treated with amphotericin B and fluconazole and responded well. A four-month-old Fox Terrier puppy from the Bay of Plenty had a history of recurrent bloody diarrhoea. Salmonella Typhimurium phage type 56 was grown from a faecal sample, confirming a diagnosis of salmonellosis. In another case of chronic diarrhoea from the Bay of Plenty, Giardia lamblia was identified by ELISA in the faeces of an eight-month-old Golden Retriever dog, confirming giardiasis. A further case of diarrhoea in a 16-month-old Bearded Collie dog from Waikato was confirmed as cryptosporidiosis by ELISA. A ten-month-old Ragdoll tomcat from Hauraki developed persistent diarrhoea, which an ELISA test confirmed as cryptosporidiosis. In another case of persistent diarrhoea, faeces from a one-year-old castrated Bengal tomcat from Manawatu tested positive for Giardia lamblia, confirming giardiasis. An eight-year-old heading dog presented at a Wairarapa veterinary clinic with clinical signs of polyuria, polydipsia and lethargy. Significant abnormalities indicating renal damage were identified by biochemical tests on a serum sample: increased creatinine (298 µmol/L; reference range 48–109), urea (36.3 mmol/L; reference range 2.5–9) and phosphorus (3.95 mmo/L; reference range 0.92–1.82). Elevated creatinine phosphokinase (5955 IU/L; reference range 0–385) indicated acute muscle damage, while increased alkaline phosphatase (122 IU/L; reference range 0–87) and alanine transaminase (164 IU/L; reference range 0–88) confirmed mild hepatobilary damage. Considering these clinical signs, leptospirosis was a possible differential. A microscopic agglutination titre (MAT) for Leptospira pomona was > 1:1600, confirming a diagnosis of leptospirosis. PORCINE Multiple fixed-tissue samples were submitted from an 11-year-old female Kunekune pig at a Waikato zoo. The pig had a long history of reproductive problems, loss of condition and abdominal swelling. At postmortem the abdomen was found to be expanded by a markedly enlarged uterus containing hundreds of cysts. Histological examination revealed diffuse tortuous cystic hyperplasia of the uterine endometrium with focal areas of epithelial dysplasia. One of the sublumbar lymph nodes was partially effaced by clusters of neoplastic cells forming tubules and cystic structures. The findings were interpreted as metastatic endometrial adenocarcinoma developing within a background of cystic endometrial hyperplasia (CEH). Adenocarcinoma arising in a background of CEH is well recognised in women and has also been reported in pigs (Harmon et al., 2004). Causes of cystic endometrial hyperplasia in pigs can include ovarian cysts (not observed in this case), anovulation, repeated cycling without breeding, obesity and exposure to the mycotoxin zearalenone. A four-day-old piglet from North Auckland had diarrhoea and was lethargic and hypothermic. Another piglet from the same litter had died after a period of diarrhoea, and the dam was lethargic. A faecal sample contained no coccidial oocysts. A faecal swab produced a growth of Escherichia coli positive for the K88 fimbrial type, suggesting that the piglets were infected with enterotoxigenic Escherichia coli (ETEC). POULTRY Five out of 50 free-range layer hens on a Taranaki farm developed diarrhoea, became listless and died within three days. Fixed-tissue sections were submitted for laboratory analysis. In the mesenteric adipose there were sheets of monomorphic neoplastic lymphocytes. Scattered foci of similar cells disrupted the liver. There were also multifocal air-sac and pulmonary granulomas centred on fragments of arthropods consistent with the mite Cytodites nudus. The clinical presentation and neoplastic infiltrates were considered to be most consistent with acute Marek’s disease, caused by Gallid herpesvirus-2. However, in the absence of characteristic sciatic nerve and iris involvement, avian leukosis could not be excluded. NON-POULTRY AVIAN A six-month-old male tui from a large mixed aviary in the Waikato region was found dead after being observed hanging around the water supply. On postmortem examination, one large yellow mass and two smaller masses were found in the left lung. These were histologically consistent with granuloma and contained many 4–7-µm-wide faintly basophilic fungal hyphae with parallel walls, acuteangle branching and frequent septa, confirming a diagnosis of aspergillosis. Underlying factors predisposing to avian aspergillosis include young and old age, poor body condition, bacterial or viral disease, significant stress, capture and transport, overcrowding, poor ventilation and exposure to particularly high spore numbers. CAMELID An 11-year-old alpaca from a Northland herd of 14 had thickened, leathery eyelids, right-corneal ulceration and left-corneal oedema, stiff lips and bent, swollen pinnae. Most serum biochemical tests were normal except for GGT (367 IU/L; normal range 12–27), confirming the effects of sporidesmin ingestion and a diagnosis of probable facial eczema. RABBIT Seven rabbits ranging from four to 10 months of age died suddenly over a period of days on a Wairarapa lifestyle farm. Very young rabbits and a number of older rabbits on the property were unaffected. Two of the dead animals were submitted for post-mortem examination. They had full stomachs, red, wet lungs (showing congestion and oedema) and dark red, mottled livers. Histology revealed similar changes in the livers of both rabbits, characterised by randomly oriented acute hepatocellular necrosis affecting about 70 percent of hepatocytes. There were clusters of degenerate neutrophils associated with necrotic areas and fibrin thrombi within sinusoids. The changes in the liver and the history of sudden death were consistent with a diagnosis of rabbit haemorrhagic disease caused by rabbit calicivirus. Kits less than three weeks old are resistant to the disease, but gradually become fully susceptible by 10 weeks. EQUINE An aged horse from the South Auckland region was pruritic and alopecic. It had not responded to treatment with chlorhexidine/miconazole medicated washes, glucocorticoid creams or trimethoprim-sulphonamide antibiotic therapy, and had been previously diagnosed with pituitary pars intermedia dysfunction. A skin biopsy showed focal suppurative epidermitis with fungal hyphae, consistent with a diagnosis of dermatophytosis. surveillance 41 (2) 2014 13 New Zealand Veterinary Pathology BOVINE A group of two-year-old Wagyu steers in Hawke’s Bay had a history of poor condition worsening over several months. One was culled and examined post mortem. Gross necropsy findings were not informative but histology showed a granulomatous hepatitis and lymphadenitis consistent with Mycobacteria paratuberculosis infection (Johne’s disease). An antibody ELISA test for Johne’s was also positive. One cow and two calves from a Hereford herd in the Auckland region were doing poorly. The cow had a history of weight loss, with several weeks of scour, and had small oral ulcers. The cow’s calf and one other calf on the property were growing poorly. All three animals were positive on bovine viral diarrhoea antigen ELISA. Bovine viral diarrhoea was diagnosed. A three-year-old cow in the Waikato presented with a large, firm, rapidly growing mass on her thigh. Aspiration of the mass and cytological examination revealed that it was composed of a monotypic population of large lymphocytes, consistent with sporadic cutaneous lymphoma. In the Waikato, a two-year-old heifer presented with sudden onset of profuse watery scour. Salmonella Typhimurium was isolated from a faecal sample. A cow in the Waikato presented with udder oedema and enlarged submandibular lymph nodes. On rectal examination a large mass about 25 cm in diameter was palpable in the area of the cervix. Haematology revealed no evidence of anaemia, but Theileria organisms were visible on the smear. In addition, increased numbers of lymphoblasts were visible on the blood smear. Early lymphoblastic leukaemia was diagnosed, likely secondary to lymphoma. An enzootic bovine leukosis ELISA test was negative. PCR for Theileria orientalis Ikeda was positive. A five-year-old bison cow in the Nelson region was thin and had a watery scour. She was sedated in the field for examination and died. Post-mortem examination revealed reduced fat stores and inflammation of the caecum and abomasum. Chemistry, parasitology and antigen testing for bovine viral diarrhoea 14 surveillance 41 (2) 2014 and coronavirus were unrevealing. Culture of intestinal contents yielded Salmonella St. Paul. A four-month-old mob of 258 Friesian calves in Canterbury were drenched with a short-acting levamisole/abamectin combination drench. The calves were not seen for three or four days, and when next seen 30 of them were dead. At that time 25 were observed to be ataxic or down, with a loss of the menace response. Over the next weekend 26 more died. Abamectin toxicity was suspected on the basis of the clinical signs. Histological examination of tissues from one of the dead calves was unrevealing, as was chemistry and haematology from a live animal. The abamectin level in a section of liver from one of the dead animals was 2.0 mg/kg. Abamectin toxicosis was diagnosed. Oral doses of above 1 mg/kg of abamectin are considered potentially toxic in cattle (Button et al., 1988). A two-year-old cow in Otago had extensive swelling beneath the jaw, with a haemopurulent discharge. Culture revealed a pure growth of an Actinomyces species. Lumpy jaw caused by Actinomyces bovis was considered to be the most likely diagnosis. In the Waikato, 10 percent of a group of calves had diarrhoea and weight loss. Yersinia pseudotuberculosis was isolated from the faeces of one of the animals. Enteric yersiniosis was diagnosed. In Hawke’s Bay, a dry-cow dairy herd of 150 animals experienced five deaths over a few days. The cows had previously been fed on citrus pulp, corn waste and barley straw, but a few days before the deaths began the barley straw was replaced with lucerne baleage. Sodium bicarbonate was also added to the feed. The cows experienced profuse diarrhoea and dehydration prior to death. Salmonella Tymphimurium was isolated from the faeces of multiple affected animals. A pasture-fed six-month-old Jersey calf in the Manawatu presented with severe depression, marked abdominal distension and weakness. Another animal was also affected and had fever and depression. The first calf died and was necropsied in the field. Gross symptoms were a marked fibrinous peritonitis, and histology showed a marked multifocal suppurative splenitis. Both lesions were associated with colonies of small Gram-negative coccobacilli. Culture of the lesions was unrevealing owing to extensive contamination and post-mortem overgrowth of bacteria. The peritonitis and septicaemia was considered to be likely caused by Pasteurella, Histophilus or Yersinia. CERVINE Seven deer in Canterbury died suddenly in a southerly cold snap. The hinds appeared thin and had little abdominal fat on post-mortem examination. One hind was scouring. Yersinia enterocolitica was cultured from the faeces of one of the affected hinds. This bacterium has not been conclusively associated with enteritis in deer in New Zealand, so its significance in this case is unknown (Gill, 1996). OVINE Five out of a mob of 130 mature Perendale ewes in the Manawatu died suddenly. Field post-mortem examination revealed abomasitis and congested areas of the jejunum. Salmonella Hindmarsh was isolated from intestinal content of one of the animals. A flock of 400 Romney sheep in Canterbury were treated for footrot with lincomycin. Two days later, nine ewes were found dead. The next day another ewe died and a postmortem examination was performed by the submitting veterinarian. Histological examination of submitted tissue revealed a severe suppurative mural rumenitis and a multifocal suppurative hepatitis. Acute rumenitis with sepsis/bacteremia and embolic hepatitis was diagnosed. Culture of the faeces for Salmonella was negative. A neighbouring flock of about 2800 Merino ewes in Canterbury were also treated with lincomycin at about the same time as the case described above. About 18 ewes and hoggets were dead three to five days after treatment. Histology on one dead animal was unrevealing, but culture of faeces from three animals resulted in the isolation of Salmonella Tennessee from two of them. EQUINE A three-year-old Warmblood horse in the Waikato presented with a large abscess on the rump. A heavy pure culture of Clostridium perfringens was isolated from fluid aspirated from the abscess. A horse in the Waikato presented with a suspect septic joint. Cytological examination of joint fluid revealed a marked increase in cellularity. Ninety percent of the visible cells were neutrophils. Culture of the joint fluid revealed a scant growth of Serratia marsescens, a ubiquitous environmental organism that occasionally causes opportunistic infections. PORCINE A group of pigs in Northland had skin lesions on the face, nares, legs and feet. The lesions were raised pustules that then became ulcers. Lesions clinically resembled a bacterial furunculosis. Histologic examination of skin biopsies from affected pigs revealed numerous parakeratotic plaques with suppurative inflammation and proliferating yeast organisms. Numerous colonies of coccoid bacteria were also present. Culture revealed Candida spp., Escherichia coli and coagulase-negative staphylococci. Candidal dermatitis with complicating bacterial infection was diagnosed. POULTRY A four-month-old rooster from a domestic flock in Otago exhibited weakness with splaying of the legs. The bird was euthanased and a post-mortem examination was performed. Histology revealed abnormal mixed lymphoid infiltrates affecting multiple organs including the central nervous system. Marek’s disease was considered the most likely cause. of Gram-positive cocci. Small colonies of Gram-negative bacilli were also visible in the lung, liver, kidneys and heart. Serratia marsescens was isolated from tissues. Serratia is a common enteric bacterium that may cause opportunistic infections of ulcerated skin, especially in immunocompromised animals. NON-POULTRY AVIAN References A zebra finch from a zoo in the Auckland region had laboured breathing and was walking oddly even though it had no visible injuries. The bird was euthanased and necropsied. Histology revealed disseminated granulomatous disease affecting the gastrointestinal tract, liver and connective tissues within the coelomic cavity. Special stains of the affected tissues revealed the presence of numerous acid-fast bacilli in the lesions. Mycobacteriosis was diagnosed. REPTILIAN A five-year-old bearded dragon (Pogona vitticeps) from a zoo in the Auckland region was lethargic and developed white/tan skin lesions. Histology showed a severe ulcerative dermatitis with numerous intralesional Gram-negative bacilli and lower numbers Button C, Barton R, Honey P, Rickford P (1988) Avermectin toxicity in calves and an evaluation of picrotoxin as an antidote. Australian Veterinary Journal 65(5): 157–158. Davis WP, Steficek BA, Watson GL, Yamini B, Madarame H, Takai S, Render JA (1999) Disseminated Rhodococcus equi infection in two goats. Veterinary Pathology 36: 336–369. Harmon BG, Munday JS, Crane MM (2004) Diffuse cystic endometrial hyperplasia and metastatic endometrial adenocarcinoma in a Vietnamese pot-bellied pig (Sus scrofa). J. Vet. Diagn. Invest. 16: 587–589. Gill J (1996) Yersiniosis of farm animals in New Zealand. Surveillance 23(4): 24–26. Vaatstra BL (2012) Stachys arvensis (Staggerweed) toxicity in lambs in New Zealand. Proceedings of the Society of Sheep and Beef Cattle Veterinarians of the New Zealand Veterinary Association – Annual Seminar 2012, Volume, p 4.11.1–4.11.8. surveillance 41 (2) 2014 15 QUARTERLY REPORT OF INVESTIGATIONS OF SUSPECTED EXOTIC DISEASES Exotic vesicular diseases ruled out A veterinary pathologist contacted MPI through the exotic pest and disease hotline after receiving samples from a group of eighteen 10–12-month-old steers. Two animals were reported to have died, with others described as having erythema and crusting around the eyes and nostrils. An MPI Incursion Investigator contacted the local veterinarian and determined that six steers from the group of 18 were variably affected and that there were no oral or foot lesions. The two deaths had occurred during the two months before this notification, with the most recent death immediately before the recent sampling event. Serum biochemistry identified raised serum glutamate dehydrogenase, aspartate transaminase and gammaglutamyltransferase in the four sampled steers, indicating moderate hepatobillary damage. A presumptive diagnosis of secondary photosensitivity (spring eczema) was made. The first mortality was attributed to the effects of massive lungworm death and disintegration after deworming the previous day. Acute facial eczema was considered the cause in the more recent case. The remaining animals received zinc boluses, were moved to a bush paddock and recovered uneventfully. Exotic vesicular disease was excluded on clinical and epidemiological grounds and the investigation was stood down. Hairy vetch toxicity investigated A veterinary pathologist rang the MPI exotic pest and disease hotline to report two deaths in dairy cows with unusual and very distinct lesions, similar to those recorded for hairy vetch (Vicia villosa) toxicity overseas. The deaths occurred on a dairy farm in Marlborough and at least one of the dead cows had been sick since finishing the turnip crop three weeks earlier. Further cases with similar pathology have since been reported from dairy farms in Rotorua and Palmerston North, each involving a single cow death. Histopathology 16 surveillance 41 (2) 2014 Exotic disease investigations are managed and reported by MPI’s Investigation and Diagnostic Centre (IDC) and Response, Wallaceville. The following is a summary of investigations of suspected exotic disease during the period from January to March 2014. in these cases was characteristic of a type IV hypersensitivity reaction, with multisystemic granulomatous and eosinophilic inflammation, often with marked lesions in the heart, kidneys and skin. Affected animals are often found dead, but if alive then clinically they can show thrombocytopaenia (often with petechial haemorrhages in the vulval mucosa), neutropaenia, marked weight loss, pruritic skin lesions (often over head and neck), pyrexia and sometimes bloody diarrhoea. Cattle can take up to five weeks before dying. Citrus pulp intoxication causes similar lesions and it is thought that other plant-based toxins, such as those present in wilted brassicas, may contain similar toxins. No definitive aetiology was found in these cases or other similar cases, though interest in this syndrome continues and a future article in Surveillance is planned. Bovine parvovirus inconclusive Environmental Science & Research (ESR) notified the MPI exotic pest and disease hotline of DNA fragments with homology to bovine parvovirus (BPV), which had been identified by Next Generation Sequencing. The sample came from aerosol samples collected at a meat processing plant. The virus is ubiquitous and not associated with disease, but this would be the first report of it in New Zealand as no surveillance has previously been performed for the organism. ESR sought to confirm that the sequence existed in the original samples by designing a custom PCR for BPV3 and was successful in amplifying DNA from four samples. Sanger sequencing performed on these samples showed 94–99 percent identity at the nucleotide level to the only other published BPV3 sequence. The finding was discussed with the MPI virology team, who agreed with MPI’s 2009 risk analysis on bovine products (that the organism is ubiquitous and does not cause disease). The Imports, Exports, Risk Analysis and Response Teams were informed of the finding and had no concerns regarding it. While the finding is not conclusive proof of the presence of BPV3 in New Zealand, it does add weight to the opinion of MPI that this non-pathogenic organism is likely to be present. Exotic bovine salmonellosis excluded A veterinary pathologist rang the MPI exotic pest and disease hotline to report a cluster of six cases of unusual haemorrhagic gastroenteritis on four large dairy farms in Canterbury and Otago during spring 2013. The disease was more often seen in adult cows, with one 2-year-old also affected, and appeared to be sporadic, with low morbidity and a high case mortality rate. The cows were usually affected as springers during the transition period, often while still grazing a crop, and presented with haemorrhagic enteritis that was rapidly fatal. Salmonella species such as Dublin (exotic) and Brandenburg (endemic) were considered a possible cause but in all cases faecal culture failed to isolate these. Intestinal histology from all five cases where a post-mortem examination was carried out showed unusual atrophy and blunting of small intestinal villi, with oedema and fibrin expanding the submucosa. In some areas there was a mild to moderate infiltration of neutrophils and macrophages among the fibrin, with oedema of the serosa and pallor of parts of the outer tunica muscularis. A questionnaire completed by veterinarians for four of these cases showed that in three cases the cows were being fed a crop with barley straw at the time of disease onset. The one animal that was not being fed crop and straw was considered by the attending vet to be different from the other cases and could possibly be excluded. The consensus among several veterinary pathologists was that the causal agent was most likely a toxin produced by an unknown bacterium. Stress of the transition period and the dietary changes that can accompany feeding a crop were likely risk factors. Owing to the sporadic nature of the disease, conclusively establishing a cause was not possible though it was most likely a toxic enteropathy. No infectious cause was found and the investigation was closed. A pathologist phoned the MPI exotic pest and disease hotline to report high mortality in calves aged three and a half to five months, at a calf-rearing facility. An unusual or exotic strain of Salmonella was suspected. Concern was elevated because of the high mortality rate (100 of 400 calves, or 25 percent). Six weeks previously the calves had developed diarrhoea and weight loss, with oral ulcerations and fever in some cases. Faecal culture isolated Salmonella Typhimurium. Treatment and preventative management (vaccination plus supportive therapy) only partly resolved the outbreak. Calves continued to die and this eventually prompted notification of MPI. Diagnostics at the time included a second faecal culture, which isolated Yersinia pseudotuberculosis, and serology, which showed elevated titres for bovine viral diarrhoea virus (BVDV). The remaining sick calves responded to antibiotics and the mortality rate declined. This was considered to be a multi-factorial outbreak of enteritis caused by coinfection by BVDV, Salmonella and Yersinia spp. BVDV can cause oral ulcerations and also results in immune system compromise, which may have contributed to the severity of the bacterial enteritis. Brucellosis excluded A district health board officer contacted MPI to report a suspect case of brucellosis in a child. The seven-year-old had recently recovered from chickenpox but had ongoing fever, joint pain and a possible heart murmur. A Brucella serum agglutination test (SAT) had returned weak positive results. The child had been in contact with farm and companion animals in New Zealand only and had no history of overseas travel. Sheep on the farm were reportedly infected with Brucella ovis, but this not a zoonotic agent and no human cases could be found in the literature. A SAT re-test one month after the initial report was negative for Brucella. This was considered to be a case of non-specific hyperimmunity following a viral disease. Zoonotic brucellosis was ruled out and the case was stood down. Contagious caprine pleuropneumonia ruled out A veterinary pathologist notified MPI of a severe fibrinous pleuropneumonia outbreak in a group of four-to-eightweek-old goat kids in the Manawatu. The disease resembled contagious caprine pleuropneumonia (CCP), an exotic bacterial disease of goats caused by Mycoplasma capricolum ssp. capripneumoniae. Possible endemic causes included Mannheimia haemolytica, Histophilus somni and Pasteurella multocida. Samples from two dead kids were sent to the MPI Animal Health Laboratory, where the agent of CCP was ruled out by PCR and culture. Culture of multiple lung, liver and pleural fluid samples was positive for Mannheimia haemolytica, which is known to cause sporadic cases and small outbreaks of acute pleuropneumonia in goat kids. In this case the young age of the kids, combined with transport and mixing, probably contributed to decreased respiratory defences, thereby predisposing to development of the disease. Unusual arteritis investigated A veterinary pathologist contacted MPI to report unusual arteritis lesions in two lambs from a Southland sheep farm. The microscopic lesions were present in multiple organs but the renal arterioles were most severely affected, with lesions resembling those seen in cattle with malignant catarrhal fever (MCF), a widespread endemic disease caused by ovine herpesvirus-2 (OvHV2). Exotic causes of vasculitis or arteritis in ruminants include orbiviral diseases such as bluetongue and enzootic haemorrhagic disease. Exotic differentials were excluded by testing of serum samples from 17 flockmates. Serum was negative for antibodies to bluetongue (by competitive ELISA) and for enzootic haemorrhagic disease (by AGID). Flockmates were tested for the presence of OvHV2 and nine of 17 were positive on nested PCR. MCF is a disease of cattle. Sheep are the host species of OvHV2, with high rates of infection but no clinical disease. Pathogenesis of MCF in cattle is thought to involve stimulation of antibody production, formation of antibodyantigen complexes within the blood, lodging of complexes in artery walls, and triggering of a type III hypersensitivity reaction with resulting arteritis or vasculitis. Several overseas reports suggest that OvHV2 can cause MCFlike lesions in lambs (Lil et al., 2005; Himsworth et al., 2008) although there are also reports of idiopathic arteritis in sheep (Ferreras et al., 2013) that somewhat complicate the picture. In the present case, it is considered most likely that these lambs suffered from MCF-like disease, possibly triggered by infection with OvHV2. Proving a causative role of OvHV2 in this case is difficult or impossible, given the existence of virus in healthy animals and the complex disease pathogenesis. Further characterisation of the OvHV2 virus involved in these cases is underway. Mycoplasma ovis confirmed A pathologist reported to the MPI exotic pest and disease hotline a goat with severe anaemia. Examination of a blood smear from the goat revealed red blood cell inclusions resembling parasites. There has been a previous historical report of Eperythrozoon ovis (now Mycoplasma ovis) in sheep in New Zealand. This species can also be passed to goats through transfer of blood. A small survey was carried out in the same management group as the affected animal. Bloods were collected from 14 randomly selected goats and nine goats were purposively selected because they had clinical signs of anaemia. The haematocrits (HCT) from two (14 percent) of the randomly selected group were anaemic (HCT < 0.27; normal 27–45). In the purposively selected group six (66 percent) were anaemic. Blood samples from the affected goats were tested for Mycoplasma ovis using conventional PCR. Two of 11 goats (18 percent) tested positive and both of these had subnormal HCT. DNA surveillance 41 (2) 2014 17 sequencing could not be carried out but the banding on gel was identical to that from an ancillary investigation where M. ovis was confirmed. No other potential differentials for anaemia in goats were detected during this investigation so M. ovis is the most likely aetiology for the anaemia observed. PRRS and PEDV ruled out A veterinarian phoned the MPI exotic pest and disease hotline to report scours and coughing among three age-groups of pigs on a lifestyle block in Otaki. Adults, neonates and juvenile pigs were affected and a significant proportion of the 25 pigs present were affected over a period of two days. Subsequently a Massey University farm veterinarian visited the property and reported that the scouring and coughing had subsided. A single sick pig was euthanased and sampled for testing to rule out porcine reproductive respiratory syndrome virus (PRRSV) and porcine epidemic diarrhoea virus (PEDV). Testing identified porcine circovirus (PCV), endemic bacterial pneumonia pathogens and parasitism. The combination of all of these likely resulted in the illthrift and clinical signs seen. The farm veterinarian was advised of the findings, vaccination was recommended and the investigation closed. Equine herpesvirus myeloencephalitis excluded A 20-year-old mare in the Wellington region developed hindlimb ataxia and weakness after being transported by float. Owing to recent interest in herpesviral myeloencephalopathy, this case was pursued to rule out herpesvirus as well as the exotic differential West Nile Virus (WNV) and other flaviviruses. Serum was negative by PCR for EHV1, WNV and generic flaviviruses antigens. The mare recovered gradually over about a week and was normal at last update. The lack of clinical progression, lack of affected herdmates and the recent history of transport meant trauma was the most likely cause of inco-ordination. The investigation was stood down. A veterinarian phoned the MPI exotic pest and disease hotline to report a foal with progressive neurological signs. The vet suspected equine herpesvirus myeloencephalitis (EHM) but the 18 surveillance 41 (2) 2014 progression of clinical signs and age of the foal were not typical of this disease. The epidemiological information also did not indicate this as a likely cause as there was no direct or indirect link of significance to the concurrent outbreak in the region. There were no other known risk factors, but the foal was on a stud farm where continual movements of horses and people, on and off the property, were part of routine business. The foal died and post-mortem samples were negative on PCR for EHV1, EHV4, EHV5, and a generic flavivirus PCR. Histopathology found no lesions in the brain but thrombosis in the liver and lung, hepatitis, and endocarditis. These findings were indicative of sepsis but bacterial culture did not isolate any pathogens (e.g. Rhodococcus equi). The only finding was a positive PCR for EHV2, which is unlikely to have been a primary cause in the death of the foal but could be a component cause. The investigation was closed and as the farm had no other clinically ill horses the risk of EHM was considered negligible. A veterinarian called the MPI exotic pest and disease hotline to report a yearling horse that was recumbent and then ataxic when made to stand, with a high temperature. The horse showed extreme behaviour that could have been a sign of a neurological problem or possibly just an indication that it was not used to being handled. This case came soon after a localised outbreak of equine herpesvirus 1 (EHV1) neurological strain in the Waikato. While this is accepted as being an endemic and sporadically occurring virus, testing was done to ascertain whether it had occurred in a different region. The PCR for EHV1 on a nasal swab and blood was negative, as was a PCR for West Nile virus. EHV1 and EHV4 ELISA tests were negative. Biochemistry and haematology results suggested an infectious process. The horse responded well to antibiotics and made a full recovery. EIA/EVA ruled out A Gribbles veterinary pathologist reported a horse for surveillance of equine viral arteritis (EVA) and equine infectious anaemia (EIA), via the MPI exotic pest and disease hotline. The horse was a New Zealand-born 26-year-old Appaloosa with anaemia (HCT = 0.18; reference range 0.24–0.44) and oedema of distal limbs. The horse was the only equid on the property and had been isolated from other horses for a number of years. A serum sample collected during examination was submitted to the Animal Health Laboratory and tested negative by serology for EVA (using VNT) and EIA (using AGID). The horse subsequently died and because of the risk assessment informed by the negative findings and travel history no postmortem was carried out. It is likely that the horse died of age-related factors. Brucella canis ruled out A veterinarian phoned the MPI exotic pest and disease hotline to report an adult male dog with suspect Brucella canis infection. The dog had inflammation of the testes and the veterinarian could not rule out B. canis on gross morphology. Histopathology on the testes indicated testicular torsion and PCR on the testicular tissue was negative for B. canis so the investigation was stood down. A veterinarian phoned the MPI exotic pest and disease hotline to report an eight-year-old French Mastiff with an acutely enlarged scrotum and subcutaneous oedema with neutrophilia. An ulcerated area was present on the right side of the scrotum. Differential diagnoses included orchitis (caused by the exotic agent Brucella canis or by endemic bacteria) and enlargement caused by neoplasia. The dog had no travel history outside of New Zealand. Fine needle aspirate of right and left testes and an enlarged inguinal lymph node was performed, which revealed large numbers of mast cells with decreased granules and an atypical appearance. The diagnosis was testicular mast cell tumour with possible metastasis to the inguinal lymph node. Serological testing was not carried out as a noninfectious aetiology was confirmed and the investigation was stood down. Avian influenza and Newcastle disease ruled out A veterinarian rang the MPI exotic pest and disease hotline to report a chicken with torticollis from a backyard poultry unit. Four out of 14 young birds had died in the last four weeks. All had hatched from the same clutch of eggs purchased together. A freshly euthanased diseased bird was postmortemed at AHL Wallaceville and samples tested negative by PCR for Newcastle disease virus and avian influenza virus. Marek’s disease was ruled out on gross pathology. Histopathology indicated multifocal hepatitis and encephalitis consistent with bacterial or viral aetiologies. An endemic cause of the disease was not determined but the investigation was stood down. A veterinary pathologist phoned the MPI exotic pest and disease hotline to report upper respiratory signs in 17 sub-adult chickens at a property belonging to a small hobby breeder in Kamo, Northland. All birds had nasal discharge and sneezing but improved over the course of several weeks, with no deaths. The farm veterinarian submitted an entire head of one bird to the veterinary pathology lab and on gross examination several pinpoint to coalescing diphtheritic plaques were noted on the respiratory mucosa. Testing for the exotic diseases avian influenza, Newcastle disease virus and Ornithobacterium rhinotracheale was performed at the AHL Wallaceville. All these results were negative. Tests for the endemic poxvirus were also negative. The investigation excluded exotic diseases and was stood down with no firm aetiological diagnosis reached. Exotic ticks ruled out A veterinarian rang the MPI exotic pest and disease hotline after finding some unusual-looking ticks on an injured shag. Samples were sent to the Plant Health and Environment laboratory (PHEL), Tamaki and identified as Ixodes eudyptidis, the endemic New Zealand seabird tick. Distemper ruled out A veterinary pathologist rang the MPI exotic pest and disease hotline after a clinically ill four-year-old Oriental small-clawed otter (Aonyx linereus) in a zoological collection tested positive on a commercial snap test ELISA for antibodies to canine distemper virus. The otter was ill with pyothorax, from which Actinomyces spp. bacteria were cultured. EDTA blood samples and nasal swabs from the affected otter and two enclosuremates were negative for distemper virus by PCR at the MPI Animal Health Laboratory and by VNT at an overseas reference laboratory. The initial positive ELISA test was presumed to be a non-specific crossreaction resulting in a false positive. The investigation was closed. References Ferreras MC, Benavides J, Fuertes M, GarcíaPariente C, Muñoz M, Delgado L, Polledo L, González J, García Marín JF, Pérez V (2013) Pathological Features of Systemic Necrotizing Vasculitis (Polyarteritis Nodosa) in Sheep. J. Comp. Path. 149: 74–81 Himsworth CG, Harms NJ, Wobeser G, Hill J (2008) Bilateral Perirenal Hemorrhage in two Stone’s Sheep (Ovis Dalli Stonei): A Possible Manifestation of Malignant Catarrhal Fever. J. Vet. Diagn. Invest. 20: 676 Lil H, O’Toole D, Kim O, Oaks JL, Crawford TB (2005) Malignant catarrhal fever-like disease in sheep after intranasal inoculation with ovine herpesvirus-2. J. Vet. Diagn. Invest. 17: 171–175 Paul Bingham Team Manager Surveillance and Incursion Investigation (Animals and Marine) Ministry for Primary Industries paul.bingham@mpi.govt.nz surveillance 41 (2) 2014 19 MARINE AND FRESHWATER QUARTERLY REPORT OF INVESTIGATIONS OF SUSPECTED EXOTIC MARINE AND FRESHWATER PESTS AND DISEASES Mediterranean fanworm range extension confirmed A mature Mediterranean fanworm (Sabella spallanzanii) was found on the hull of a vessel on a swinging mooring at Opua, Bay of Islands. In response, the Northland Regional Council (NRC) had the vessel slipped and cleaned at the next available opportunity. Fanworms have previously been found in Northland and the species is established in Whangarei Harbour but the NRC is still running elimination programmes for this species in this location. The vessel had come from Halfmoon Bay, Auckland, where it had apparently been anti-fouled five months previously. The Response team was engaged to liaise further with the NRC. The next round of surveillance was conducted at Opua four months later and found no fanworms, so the investigation was stood down. 20 surveillance 41 (2) 2014 Exotic marine pest and aquatic disease investigations are managed and reported by MPI Investigation and Diagnostic Centre and Response, Wallaceville. The following is a summary of investigations of suspected exotic marine diseases and pests during the period from January to March 2014. During a round of port surveillance at Whangarei, divers found a high level of hull fouling on the underside of a recentlyarrived fishing vessel. The fouling included several thousand large Mediterranean fanworms (Sabella spallanzanii). The vessel was subsequently manually cleaned by divers under direction of the Northland Regional Council (NRC). It had spent considerable time in Napier, Gisborne, Tauranga and Bluff since leaving Auckland in 2011. Response teams were engaged, regional councils were contacted and surveillance was undertaken in these places. Although the direct risk from the fanworms on the hull of the vessel concerned has been mitigated by NRC actions, the presence of this infected vessel in areas from which the Mediterranean fanworm has not been reported is a matter of considerable concern. The Response teams and regional authorities are co-ordinating further surveillance and the present investigation has been closed. Paul Bingham Team Manager Surveillance and Incursion Investigation (Animals and Marine) Ministry for Primary Industries paul.bingham@mpi.govt.nz PLANTS AND ENVIRONMENT WEIGHING UP THE COSTS OF SURVEILLANCE TRAPPING AND THE LIKELY BENEFITS FROM AVOIDING FUTURE PEST DAMAGE The use of attractant-baited traps for surveillance can enable the early detection of insect pests before eradication becomes impossible. In New Zealand, MPI carries out surveillance trapping for a few key insect pests, including gypsy moth (Lymantria spp.) and fruit flies (Tephritidae) (Acosta and White, 2011). An external evaluation of New Zealand’s Forest Health Surveillance Programme, commissioned by the Forest Owners Association in 2007, recommended the implementation of a trap-based surveillance programme for detecting bark beetles and wood-boring insects. These insects include some of the most serious forest pests worldwide. Assisted by the worldwide movement of wooden packaging materials and live plants, many such species have become successful invaders, often causing substantial and costly damage to forests. Recent examples overseas are the emerald ash borer (Agrilus planipennis), Asian long-horned beetle (Anoplophora glabripennis) and red-bay ambrosia beetle (Xyleborus glabratus) (Aukema et al., 2010). Numerous exotic borers pose a potential threat to New Zealand’s forest biosecurity and could have serious implications for our plantation forests and urban trees (Brockerhoff, 2009). A trap-based surveillance programme (Brockerhoff et al., 2006) could enable earlier detection of these pests, increase the likelihood of success and lower the costs of eradication and containment, thus reducing the overall cost of invasions. A recent collaboration between scientists in New Zealand and the United States aimed to develop a detailed estimate of the costs and benefits of a surveillance trapping programme for these pests in New Zealand. Cost-effective surveillance strategies must account for tradeoffs between investment in surveillance and eventual control costs and damages caused by invaders. The benefits of such a programme are the expected avoided costs resulting from the enhanced surveillance, less the costs of the programme. Figure 1: Conceptual diagram illustrating the main components of the cost-benefit analysis of surveillance trapping for invading wood borers and bark beetles. The analysis incorporates scenarios for establishment, population growth and damages over time; trap density and likelihood of detection and eradication relative to the size of infestations. Figure 2: Once a population has been detected, eradication can be attempted at a cost that increases with the size of an infestation. Invading populations cause damages to urban and plantation forests for a number of years or until successful eradication. The cost-benefit analysis compares the cost of trapping with the benefits of reduced damages and lower eradication and management costs. surveillance 41 (2) 2014 21 We developed and used a mechanistic bio-economic model to represent invasive species establishment, spread, detection, control and impacts. The model specifically relates the background rate of population establishment (b), surveillance intensity (i.e. trap density, d) and the size of an invading population over time, to the probability of the population being detected. This determines the expected success and costs of eradication or control programmes (Figures 1 and 2). The model can be used to evaluate specific surveillance programmes and to optimise programme design to provide the greatest benefits. We considered damage to both urban and plantation forests in our analyses, based respectively on estimates of urban tree replacement cost and harvest value reduction. We evaluated the implementation of a 30-year surveillance programme focused on the four ports (Auckland, Tauranga, Wellington and Christchurch) that receive the most imports (apart from some bulk cargoes like petroleum) and hence have the highest entry risk for wood borers and bark beetles. We also conducted analyses to determine how sensitive the surveillance programme’s cost-effectiveness is to uncertainty in different inputs to the model. For example, the rate of future establishment of harmful wood borers and bark beetles is uncertain. The implementation of the International Standard of Phytosanitary Treatments No. 15 (ISPM 15) is expected to have reduced the establishment rate, but it is not 100 percent effective and there has been a considerable increase in trade and pathway volume by which borers can arrive (Haack et al., 2014, Leung et al., 2014). Nevertheless, ISPM 15 is expected to be beneficial (Leung et al., 2014), although there is still some risk (Brockerhoff et al., 2014). We allowed for this in our cost-benefit analysis and applied three different establishment rate scenarios, including the recent (1980–2011) average establishment rate in New Zealand and half that rate. Our findings indicated that a surveillance trapping programme for invasive wood borers and bark beetles would have net benefits under all scenarios considered. Several examples are shown in Figure 3. Even a modest number of traps would be expected to be beneficial. For example, with just 200 traps deployed continuously for 30 years at an estimated present-value cost of US$1.7 million1 (US$100 000 a year), there would be a net present benefit of US$142 million (US$9.2 million a year) in reduced urban and plantation forest damage (EpanchinNiell et al., 2014). With 1000 traps costing about US$5.6 million (present value) (US$400 000 a year), the expected net present-value benefit would be about US$227 million (US$14.8 million a year). However, the optimal trapping strategy involves a relatively high investment, with about 10 000 traps at an estimated 350 300 Surveillance cost over 30 years 50 Expected net benefits 250 40 200 30 150 20 100 10 50 0 0 50 200 400 Total number of traps 1000 Expected net benefits (millions USD) Surveillance cost over 30 years (million USD) 60 10000 cost of US$54 million (present value2) (US$3.5 million a year). This strategy would provide an expected net presentvalue benefit of about US$300 million (US$19.5 million a year) by reducing the expected total eradication cost and damage from pests that might have become established, and this would provide a 39 percent cost reduction. The extent of predicted net benefits varies among the four port cities we considered. The greatest benefits would be expected in Tauranga and Auckland, where more imports and invaders arrive than is the case in Christchurch and Wellington (Epanchin-Niell et al., 2014). Sensitivity analyses suggest that these findings hold even after allowing for uncertainty in the model. While surveillance is expected to reduce the longer-term damage from invasive wood borers and bark beetles, there are other factors to consider: whether the invasions actually eventuate; whether they are detected, and what the degree of eradication success is. These factors are all influenced by stochasticity and cannot be predicted with certainty. The actual benefits will also depend on the particular species and their potential severity, the circumstances under which they are detected, and how the agencies concerned respond (i.e. eradication efforts). Actual damage might be greater or less than our analyses suggest. Owing to this uncertainty, and in recognition of the limited funds available, we recommend that a trap-based surveillance programme be implemented whereby the level of surveillance effort could be scaled to the available funds. It is possible to determine an optimal surveillance strategy, in terms of trap numbers and locations, in relation to the funds available. We note that more damage is expected in urban forests, where most invasions begin, than in the more remote plantation forests. Therefore, with any surveillance programme for wood borer and bark beetles there are many more beneficiaries than just the forestry industry . References Acosta H, White P (2011) Atlas of Biosecurity Surveillance. Ministry of Agriculture and Forestry, Wellington, New Zealand. Figure 3: Relationship between the number of traps and the costs and expected benefits of surveillance trapping We used US dollars as the base currency of our analyses as New Zealand’s logs are traded in this currency and because it enables comparisons with similar studies in other countries. The long-term average exchange rate of NZ$1=US$0.65 was used throughout. For a 5 percent discount rate. 1 22 surveillance 41 (2) 2014 2 Aukema JE, McCullough DG, Von Holle B, Liebhold AM, Britton K, Frankel SJ (2010) Historical accumulation of nonindigenous forest pests in the continental United States. BioScience 60: 886–897. Brockerhoff EG (2009) Wood borer and bark beetle risk analysis. Scion Report number 16833, for New Zealand Forest Biosecurity Research Council. 23 pp. Brockerhoff EG, Jones DC, Kimberley MO, Suckling DM, Donaldson T (2006) Nationwide survey for invasive wood-boring and bark beetles (Coleoptera) using traps baited with pheromones and kairomones. Forest Ecology and Management 228: 234–240. Brockerhoff EG, Kimberley M, Liebhold AM, Haack RA, Cavey JF (2014) Predicting how altering propagule pressure changes establishment rates of biological invaders across species pools. Ecology 95: 594–601. Epanchin-Niell RS, Brockerhoff EG, Kean JM, Turner JA (2014) Designing cost-efficient surveillance strategies for early detection of invasive species: a case study on wood borers and bark beetles. Ecological Applications, in press. http://dx.doi.org/10.1890/13-1331.1. Haack RA, Britton KO, Brockerhoff EG, Cavey JF, Garrett LJ, Kimberley M, Lowenstein F, Nuding A, Olson L, Turner J, Vasilaky K (2014) Effectiveness of the International Phytosanitary Standard ISPM No. 15 on reducing wood borer infestation rates in wood packaging material entering the United States. PLoS ONE 9(5): e96611. Leung B, Springborn MR, Turner JA, Brockerhoff EG (2014) Pathway level analysis of trade policy for reducing invasive species risk: synthesis, estimation and identification of data needs. Frontiers in Ecology and the Environment 12: 273–279. Eckehard G. Brockerhoff Scion (New Zealand Forest Research Institute) P.O. Box 29237, Christchurch; and Better Border Biosecurity (B3, b3nz.org) eckehard.brockerhoff@scionresearch.com Rebecca S. Epanchin-Niell Resources for the Future 1616 P Street NW Washington, DC 20036 USA Epanchin-Niell@rff.org John M. Kean AgResearch Ruakura Research Centre Private Bag 3123 Hamilton 3240; and Better Border Biosecurity (B3, b3nz.org) john.kean@agresearch.co.nz James A. Turner AgResearch Ruakura Research Centre Private Bag 3123 Hamilton 3240 James.Turner@agresearch.co.nz surveillance 41 (2) 2014 23 PLANTS AND ENVIRONMENT BIOSECURITY RISKS ASSOCIATED WITH TRADING ONLINE AND GIFTS FROM OVERSEAS Post-border exotic pest and disease incursions threaten New Zealand’s economy, environment, health and cultural identity. Worldwide, the increasing availability and volume of on-line internet trade of plant material is an emerging biosecurity risk. Two recent cases highlight the challenges posed by importation via the internet. MPI was notified by a member of the public of a plant product received as a gift purchased from an overseas company’s website. The product was a can that contained a viable Canavalia ensiformis (Jack bean) seed and planting substrate. The plant did not meet the requirements for import into New Zealand as it was not recorded on the Plant Biosecurity Index (PBI). Species not listed on the PBI are ineligible for import as they are not covered by a valid Import Health Standard (IHS). The plant was deemed a new organism under the Hazardous Substances and New Organisms (HSNO) Act 1996 so it was seized by MPI staff and destroyed. MPI contacted the overseas company, identified the risk item and requested that the product be removed from sale. The response was swift and the product was immediately removed for sale to New Zealand customers. This was an excellent outcome that required minimal effort, partly owing to the proactive actions of the recipient of the gift. The second case concerned an illegal import of a green alga (Aegagropila linnaei) through the International Mail Centre (IMC) from a large overseas web store. Known as marimo (in Japan), or moss balls (in aquarium shops), or lake balls, this filamentous green alga forms spherical balls several centimetres in diameter (Figure 1) although it can also occur in different growth forms depending on environmental conditions (Boedeker & Immers, 2009). In Japan, marimo is a protected species (Kurogi, 1980) and in the northern hemisphere lake balls are commonly used to filter debris in fish tanks. A. linnaei is not present in New Zealand and if introduced could adversely impact native aquatic plants and ecological 24 surveillance 41 (2) 2014 Figure 1: Lake balls (Aegagropila linnaei) in Lake Akan, Hokkaido, Japan (photo: I. Wakana) systems, with devastating consequences (Ingram, 2012). Under the HSNO, A. linnaei is not eligible for import into New Zealand as it is not covered by a valid IHS under the Biosecurity Act 1993. After ordering the moss balls the New Zealand buyer contacted the New Zealand Customs Service to confirm the legality of importing them. The enquiry was referred to MPI and the local buyer provided helpful information about the purchase and website. The buyer immediately advised MPI when the shipment was delivered and an MPI Quarantine Inspector retrieved the illegally imported product. Before the moss balls were destroyed they were used by MPI staff to train detector dogs at the IMC. This was a valuable and positive outcome from the investigation. The web store (or e-shop front) used for the purchase of the moss balls, like many similar websites, did not directly control what it sold. The challenges posed by the increasing availability of goods on line will likely increase in volume and complexity. These cases demonstrate the importance of New Zealand’s biosecurity system and illustrate the pivotal role that New Zealanders can play in biosecurity. Encouraging the public to do the right thing when trading on line or receiving gifts from overseas helps protect New Zealand from biosecurity risks. References Boedeker C, Immers A (2009) No more lake balls (Aegagropila linnaei Kützing, Cladophorophyceae, Chlorophyta) in The Netherlands? Aquatic Ecology 43: 891–903. Kurogi M (1980) Lake ball “Marimo” in Lake Akan. Jap. J. Phycol. 28: 168–169. Ingram K (2012) Aquaculture biosecurity risks. New Zealand Aquaculture, November/ December, 3. Carolyn Bleach Incursion Investigator Surveillance and Incursion Investigation Group Ministry for Primary Industries Carolyn.Bleach@mpi.govt.nz plants and environment investigation report: january to march 2014 Brown crazy ant found at Ports of Auckland The invasive brown crazy ant (Paratrechina longicornis) was found in February 2014 through the National Invasive Ant Surveillance Programme, which is carried out annually at ports and high-risk Transitional Facilities around the country. The pest control company Flybusters Antiants visited the site at Ports of Auckland and found P. longicornis trailing near the base of a light pole on the Fergusson Container Terminal. It is common to find ants around light poles and electrical systems. Exterm-An-Ant toxic bait was placed to encourage ants to forage and recruit to the bait. A nest was identified in a gap in the concrete at the base of the pole and two larger nests were found further out. The nest age, based on worker numbers, was estimated at about a month for the light pole nest and for the two bigger nests, 2–3 months. The surrounding area was sprayed with a residual insecticide and Exterm-An-Ant toxic ant café bait stations were deployed. After two weeks a final site visit was undertaken to check treatment efficacy and the areas were re-baited with Exterm-An-Ant. A single dead P. longicornis was found in an ant café bait station adjacent to the light pole. No further ants were seen in the area, indicating that all nests were destroyed. Exotic ant found at Auckland Transitional Facility Sixteen specimens of an exotic ant species, Monomorium sp., were found at an Auckland Transitional Facility during the National Invasive Ant Surveillance (NIAS) survey in February 2014. Flybusters Antiants visited the site. The original NIAS find was near a bunker used for storing dangerous goods. Visual searches were undertaken and attractant bait was laid but no ants were seen. Two follow-up surveys a week apart were undertaken with attractant re-baiting but no more ants were seen. The area was treated with a residual insecticide and toxic baits were laid. The area was considered unlikely to be suitable for nest establishment because of high vehicle disturbance (close to a road), dry site and little ant habitat. The case was closed. Lora Peacock Senior Adviser Surveillance and Incursion Investigation Group Ministry for Primary Industries Lora.peacock@mpi.govt.nz surveillance 41 (2) 2014 25 PEST WATCH: 15 FEBRUARY 2014 – 16 MAY 2014 Biosecurity is about managing risks: protecting New Zealand from exotic pests and diseases that could harm our natural resources and primary industries. MPI’s Investigation & Diagnostic Centres and Response (IDC & R) directorate devotes much of its time to ensuring that new organism records come to its attention, and to following up as appropriate. This information was collected from 15 February 2014 to 16 May 2014. The plant information is held in the MPI Plant Pest Information Network (PPIN) database. Wherever possible, common names have been included. Records in this format were previously published in the now discontinued magazine Biosecurity. To report suspect new pests and diseases to MPI phone 0800 80 99 66. Validated new to New Zealand reports Type Organism Host Location Submitted by Comments Bacterium Ensifer medicae no common name Melilotus indicus King Island melilot Coromandel IDC & R (General Surveillance) Melilotus indicus is able to produce nitrogen-fixing root nodules through the microsymbiont Ensider medicae, which has a cosmopolitan distribution. Fungus Colletotrichum petchii no common name Dracaena deremensis no common name Coromandel IDC & R (General Surveillance) Host-specific fungus that causes black lesions on leaves that slowly progress toward the stem. Fungus Coniella fragariae no common name Fragaria x ananassa strawberry Auckland IDC & R (General Surveillance) Causes leaf spot on strawberry. Fungus Fusarium lactis no common name Capsicum annuum sweet pepper Mid Canterbury IDC & R (General Surveillance) An internal rot of sweet pepper. No external symptoms observed, though seeds and interior of the fruits were covered with fungal mycelium. Mite Euseius elinae phytoseiid mite Erythrina sp. coral tree Auckland IDC & R (General Surveillance) Predatory mite on leaf with a phytophagous mite (Tetranychus ludeni) infestation. Endemic to Australia. Used for biological control in Australian horticulture. If you have any enquiries regarding this information please contact surveillance@mpi.govt.nz. 26 surveillance 41 (2) 2014 gribbles veterinary pathology To report suspected exotic land, freshwater and marine pests, or exotic diseases in plants or animals, call: 0800 80 99 66 Investigation and Diagnostic Centre – Wallaceville 66 Ward Street Upper Hutt Tel: 04 526 5600 Investigation and Diagnostic Centre – Tamaki 231 Morrin Road St Johns Auckland Tel: 09 909 3568 Investigation and Diagnostic Centre – Christchurch 14 Sir William Pickering Drive Christchurch Tel: 03 943 3209 • AUCKLAND Courier: 37–41 Carbine Road, Mount Wellington, Auckland 1060 Postal: PO Box 12049, Penrose, Auckland 1642 Tel: 09 574 4701 Fax: 09 574 5304 • HAMILTON Courier: 57 Sunshine Ave, Hamilton 3240 Postal: PO Box 195, Hamilton 3240 Tel: 07 850 0777 Fax: 07 850 0770 • PALMERSTON NORTH Courier: 840 Tremaine Avenue, Palmerston North 4440 Postal: PO Box 536, Palmerston North 4440 Tel: 06 356 7100 Fax: 06 357 1904 • CHRISTCHURCH Courier: 7 Halkett Street, Christchurch 8140 Postal: PO Box 3866, Christchurch 8140 Tel: 03 379 9484 Fax: 03 379 9485 • DUNEDIN Courier: Invermay Research Centre, Block A, Puddle Alley, Mosgiel, Dunedin 9053 Postal: PO Box 371, Dunedin 9053 Tel: 03 489 4600 Fax: 03 489 8576 NEW ZEALAND VETERINARY PATHOLOGY • AUCKLAND Courier: NZCCM, Gate 2, Auckland Zoo, Motions Road, Western Springs, Auckland 1022 Postal: PO Box 44 422, Point Chevalier, Auckland 1246 • HAMILTON Courier: Cnr Anglesea and Knox Streets, Hamilton Postal: PO Box 944, Hamilton Tel: 07 839 1470 Fax: 07 839 1471 • PALMERSTON NORTH Courier: IVABS Building, 1st Floor, Massey University, Tennant Drive, Palmerston North Postal: PO Box 325, Palmerston North Tel: 06 353 3983 Fax: 06 353 3986