Coccidia in Birds - NCSU Veterinary Parasitology

Coccidia in Birds
• Intestinal coccidiosis in birds caused by
Eimeria spp.
• Pathology due to destruction of intestinal
cells
• Hemorrhage, malabsorption - can be
present prior to patency
• Each species has tissue site specificity
• Subclinical infection impacts on production
Comparison of
Eimeria necatrix
and
Eimeria tenella
E tenella
Fowl coccidiosis
Intestinal sites for various Eimeria
spp. infecting chickens
• Different age classes of birds most
affected by different species
• Chickens - E. tenella (cecal coccidiosis -4
wk old), E. necatrix (>6 wk), E. acervulina
(quail), E. maxima, E. mivati, E. brunetti
• Mixed infections common
• Turkeys - E. adenoeides, E. meleagrimitis
• Host species specific
Treatment and Control of Avian
Coccidiosis
• Sanitation
• Young birds most at risk
• Coccidiostats in feed or water - must
rotate drugs as resistance develops with
continual usage of single or closely related
drugs
• Vaccines - oocyst cocktails, irradiated,
mutated - recombinant antigen vaccines in
future - Inovocox vaccine (Embrex)
Control of Avian Coccidiosis
• Drug resistance a problem
• Drugs switched in middle of growing
period or switching classes of drugs (>25
available)
• Some drugs , e.g., sulpha drugs given in
an interrupted fashion so as to allow
immunity to develop during an outbreak of
clinical disease
Eimeria leukarti
• Horses
• Non pathogenic
• Oocyst large (~58 x 87 microns - thickwalled), dark brown, resembles melon
seed with micropyle - heavy, use
sedimentation technique – not a problem
so don’t bother looking
Swine Coccidiosis
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• Eimeria debliecki and E. scabra
• Acute enteritis limited to lower sm intestine
• Characteristic yellow fibronecrotic
pseudomembrane often accompanied by
bloody diarrhea
• Diagnose during acute prepatent phase by
examination of gut
Isospora suis
• Important etiologic agent of porcine
neonatal coccidiosis
• Important to distinguish from viral and
bacterial diarrheas of piglets
• Nonhemorrhagic diarrhea in 7-10 d old
pigs
• Feces initially yellow changing to gray and
pasty, becoming more fluid over time
• Asexual stages most pathogenic
• Sporulation time ~ 24h favoring explosive
outbreaks
• Control with sanitation-slatted floors
• Usually not a problem in well managed
facilities
Coccidial Infections of the Dog
and Cat
Isospora and Cystoisospora
Isospora dogs and cats
Isospora spp. Dog/Cat
• Eimeria does not infect dogs/cats
• Isospora canis - homoxenous or
heteroxenous lc - sporulation time 4 dmouse can carry cystozoite
• Pathology ??? 105 sporulated oocysts
does not cause pathology in puppies
• Isospora wallacei
• heteroxenous lc
• Raw meat source of infection
• Pathology - I. canis and I. wallacei
possible bloody or mucoid diarrhea,
abdominal pain, dehydration, anorexia,
vomiting
• Isospora felis - lc similar to I. canis
Treatment and control of
coccidiosis in dogs and cats
• Infection ubiquitous, especially kittens and
puppies
• Pathology associated with poor sanitationaccumulation of sporulated oocysts
• Immunity develops following exposure
• Sulfadimethoxine drug such as Albon®,
Bactrovet®, or Tribrissen®
• Treat with Albon (sulfadimethoxine) for at least 5
days - must limit re-exposure – however efficacy
of this drug unclear!!!!
• Almost all puppies and kittens acquire
coccidial infections but usually no need to
treat