E. coli Infections in Poultry By Eric Gingerich, DVM

As published in
E. coli Infections in Poultry
By Eric Gingerich, DVM
Technical Service Specialist - Poultry
Diamond V
Escherichia coli (E. coli for short) is a Gram negative bacterium that can cause a various forms of
disease in poultry. Diseases caused by E. coli are called colibacillosis and may infect all classes
and ages of poultry. The E. coli bacterium is ubiquitous wherever fecal material from animals is
found. E. coli related diseases continue to be at or near the top of lists of disease issues for
broilers, turkeys, and egg layers. The different disease syndromes and their control are described
herein.
Yolk infections in chicks and poults due to E. coli are primary infections from exposure to the
bacterium during the hatching process. Egg shell contamination is the main reason for the
exposure although poor hatcher sanitation can leave a residue of E. coli from the previous hatch.
Losses normally occur during the first three days of life and present clinically as normal sized
chicks on feed but dead. Lesions of caseous yolk material are often seen. Culture of this yolk
material is used for diagnosis to differentiate from other possible bacterial causes such as
Salmonella spp., Pseudomonas spp., Staph. aureus, etc. Treatment with antibiotics is normally
not used because the course of the disease is so short-lived that by the time a diagnosis is
obtained, the disease losses are nearly complete. Effective prevention means only utilizing clean
hatch eggs by using effective nest management and sanitation techniques. Also, the use of an
effective hatcher and hatcher tray sanitation program is important. The use of Diamond V Original
XPC in feed can also be an aid as E. coli levels in the breeder feces will be less, reducing nest
contamination.
E. coli infections secondary to respiratory infections in broilers, egg-type pullets and layers, and
turkeys, is an important disease scenario. The normal respiratory tract has the capability to
remove E. coli and other bacteria from deep in the respiratory tract due to the action of ciliated
epithelial cells lining the trachea. In respiratory disease situations such as Bordatella avium in
turkey poults, infectious bronchitis in chickens, Mycoplasma gallisepticum infections in both
turkeys and chickens, the epithelial cells of the trachea and bronchi of the lungs undergo changes
that do not allow normal function of these cells. Hence E. coli numbers increase and infection of
the respiratory tract occurs. The initial lesion seen when E. coli infection is established is a
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caseous airsacculitis. The deadly and chronic lesion seen with E. coli infection is a caseous
peritonitis, perihepatitis, and/or pericarditis.
House management practices can play a role in the incidence and severity of E. coli infections.
Low ventilation rates that lead to high atmospheric ammonia, increased litter moisture, and high
dust counts in the air all will aid in carrying more E. coli deep into the respiratory tissues.
Increased litter moisture also has the effect of increasing the survivability and reproduction of E.
coli bacteria.
Egg layer colibacillosis is viewed as a primary disease due to E. coli. It is most often seen at the
onset of egg production but can be seen at older ages as well. The sources of infection appear to
be water, dust, or fecal material pecked off equipment. The stress of recent movement and the
onset of egg production appear to be factors in the onset of the disease early in lay. One theory is
that the young layer’s everted reproductive tract during egg laying is quite susceptible to infection
with E. coli and the bacterium infects the bird by moving retrograde up the oviduct.
Turkey poults suffer an E. coli related syndrome after viral enteritis. This is due to overgrowth of
E. coli in the intestine from poor digestion of nutrients and a buildup of these undigested nutrients
in the lower intestine. Poult death losses can be quite high with lesions seen as a septicemia or
caseous peritonitis, perihepatitis, and/or pericarditis.
Antibiotic treatment of older flocks infected with colibacillosis has met with much less success
recently than in the past due to widespread antibiotic resistance and the lack of new and effective
antibiotics to take their place. For example, there is only one antibiotic preparation available to
treat bacterial infections in egg layers in production. The tetracyclines and sulfa drugs are
available for use in broiler and turkey flocks. A very effective antibiotic, enrofloxacin, was taken
away from the industry by FDA several years ago due to the ill-perceived notion that enrofloxacin
was being used in feed or as a widely used preventative medication and not as a therapeutic as
intended.
Treatment now involves supportive measures to aid in reducing the level of infection for the
remaining flock members as follows:
• Vaccination with the live E. coli vaccine;
• Fogging (nebulizing) disinfectants such as VirkonS or chlorine dioxide;
• Sanitizing water with five to 10 ppm chlorine or six to 12 ounces of iodine disinfectant per
gallon of stock solution metered at one ounce per gallon drinking water;
• Collecting dead birds more frequently to remove them as a source of infection in an
attempt to decrease the disease cycle;
• Replacing wet litter with dry in floor houses;
• Adding an intestinal health aid such as Diamond V Original XPC will give some
immediate boost of the immune system while prolonged use will aid in improving the
microflora makeup.
Prevention of E. coli infections is therefore the main control measure used. Several preventative
practices are available as follows:
• Intestinal health aids. Several research-backed products are on the market. Diamond V
Original XPC has been shown to reduce E. coli levels in the cecum when fed at
recommended levels and would aid in reducing contamination levels in the birds’
environment and improve their response to invading bacteria.
• Water sanitation. Routine sanitation of water with either chlorine or iodine can be very
effective in reducing bacterial infections.
• Vaccination. The live E. coli vaccine has been a very useful tool in egg layers and is
being evaluated in broiler and turkey flocks. In egg layers, two to three doses are applied
by spray during the growing period prior to housing. Booster applications are given to
some flocks prior to molting.
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Ventilation practices. Reducing ammonia levels by providing the proper ventilation rates
and temperatures throughout grow for broilers will keep litter dry and reduce the release
of ammonia from the litter. Keeping the stored manure dry in high-rise layer houses is
also important in reducing ammonia. The use of manure drying fans in the pits of highrise houses has been a great aid in reducing moisture of the manure piles.
Moving age of egg layers. Moving egg layer pullets at least one to two weeks prior to the
onset of production will aid in getting the birds’ microflora stabilized and the birds
exposed to pathogens in the new layer house environment prior to the stress of egg
production. Spreading out these stressors appears to reduce the problems with early lay
E. coli problems in egg layers.
Typical lesions of colibacillosis in layers – Caseous Peritonitis
Lesions of Colibacillosis in a Broiler – Caseous pericarditis and perihepatitis
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Colibacillosis in a chick – Note full crop and enlarged yolk full of caseous exudates
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