Unit 1 - Avian Part 3 (Enteric) Flashcards
What is the etiologic agent for coccidiosis?
Eimeria
True or False: Eimeria is not host specific?
False - Eimeria is very host specific
How is coccidiosis transmitted?
Fecal oral transmission
When are birds often infected by coccidiosis?
After 3 weeks of age
How long does it take for Eimeria oocysts to sporulate and become infective?
1-3 days
Commercial poultry may go through __ rounds of infection before becoming immune.
3
True or False: Bloody diarrhea is always observed with coccidia infections.
False - some coccidia do not invade the intestinal mucosa as deeply and bloody diarrhea is not always observed
What clinical signs are associated with coccidia infections that do not invade the intestinal mucosa?
Weakness, depression, and necrotic enteritis
What clinical signs are associated with coccidia that invade more deeply into the intestinal mucosa?
More severe disease, bloody diarrhea, and necrotic enteritis
In the absence of preventative measures what population of birds can have 50% mortality due to coccidiosis?
Farmyard pheasants, quail, and partridges
How is coccidiosis prevented?
sanitation and immunization
What type of bedding is bad for coccidiosis overgrowth?
Wet litter and mud
What in bedding will kill coccidia oocysts
Ammonia
What types of vaccines are available for coccidiosis?
Live attenuated vaccines for some species
Non-attenuated vaccines with low doses of sporulated oocysys
What is the benefit of a low dose vaccine against coccidiosis?
Low doses allow time to develop an immune response
Why are coccidiostats problematic?
Drug resistance is a big problem
Most coccidiostats allow for come _____ of coccidia and allow for development of immunity.
replication
What are coccidiostats often used in combination with?
Vaccines
Explain the protocol for using coccidiostats with vaccines.
Clean up a facility first to get rid of resistant coccidia
Inoculate new birds with coccidia that are still susceptible to coccidiostats
Treat with coccidiostats as needed to control clinical signs
What is used to treat coccidiosis?
Amprolium, Avatex, tetracyclings, and sulfa drugs
What drug is not recommended for treatment of coccidiosis because of the very long withdrawal time?
Ponazuril
What is infectious bursal disease (IBD) also known as?
Gumboro disease
What is the etiologic agent of IBD?
Avibirnavirus in the Birnaviridae family
There are two serotypes of IBD, which one causes disease?
Serotype 1
What is the mortality rate for classical strains of IBD?
20-50%
How do variant strains of IBD present?
No clinical signs or mortality - just lymphocyte depletion without inflammation of bursa
What is the mortality rate for vvIBD?
50-100%
True or False: Disinfectants are key to IBD control
False - they are very resistant to infections
What age group has the highest mortality due to IBD?
Between 3-6 weeks of age
When are chickens no longer susceptible to IBD?
The bursa stops functionig by 16 weeks and they are no longer susceptible
What is the main problem associated with IBD?
immunosupperssion
What does the IBD virus attack?
IgM and B-cells in the bursa
At what age can infection with IBD result in permanent immunosuppression?
If infected <3 weeks of age
At what age can infection with IBD result in reversible immunosuppresion?
6 weeks of age
What clinical signs are associated with IBD?
Feathers around the vent are stained with feces containing lots of urates
Depression, diarrhea, anorexia, incoordination
depression
Ruffled feathers especially in the head and neck area
What lesions are associated with IBD?
Initial enlargement of the Bursa of Fabricius and subsequent atrophy
Hemorrhages in the bursa, muscles of the legs, and breast
Severe urate deposition in the kidneys
How is IBD diagnosed?
Histopathology, virus isolation, serology, ELISA, and virus neutralization
How is IBD prevented and controlled?
Thorough cleaning and disinfection of facilities
Killed vaccine for breeders
MLV vaccine for chicks
Recombinant HVT
What is the etiologic agent of necrotic enteritis?
Clostridium perfringens mostly type A and some C
True or False: Chickens with multiple strains of Clostridium perfringens usually do not have disease
True
Diseased chickens with necrotic enteritis usually have a single pathogenic strain or clone. What do these strains produce?
Bacteriocin that kills off other C. perfringens
Ned B
Collagenase
What are the predisposing factors for necrotic enteritis?
High energy, high protein feeds, high levels of small grains
Subclinical coccidiosis or salmonellosis
What population of chickens are mostly affected by necrotic enteritis?
Mostly broilers and some layers
What clinical signs are associated with necrotic enteritis?
Dark, blood-stained feces, dehydration, sudden deaths, ataxia, somnolence, depression, and poor weight gain with ‘subclinical’ cases
What part of the intestine does necrotic enteritis affect?
Mid to distal small intestine
If necrotic enteritis is treated, the mortality can be around ____%. If untreated, mortality can be ____%.
2%, 50%
How is necrotic enteritis diagnoised?
With gross lesions and demonstration of organisms on mucosa
How is necrotic enteritis prevented?
Controlling coccidia
How is necrotic enteritis treated?
Penicillins or other antibiotics in drinking water
What species does gangrenous dermatitis affect?
Turkeys and chickens
What causes gangrenous dermatitis?
Clostridium septicum, C. perfringens Type A, and staphylococcus aureus singly or in combination
Gangrenous dermaititis has _____ onset, and (acute/chronic) mortality.
Rapid, acute
What is gangrenous dermatitis?
Necrosis of the skin and subcutaneous tissues
What is gangrenous dermatitis often associated with?
Immunosuppression such as with infectious bursal disease or other infections
What can help eliminate gangrenous dermatitis from a facitlity?
Thorough cleaning and disinfection
What is salmonellosis also known as?
Pullorum disease
What is the etiologic agent of pullorum disease?
Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum
What population of birds is Salmonellosis of concern for?
Home-raised chicks, gamebirds, etc.
How is Pullorum disease transmitted?
Bird to Bird transmission, contact, cannibalism, wound contamination, and fecal contamination
Can eggs become infected with Salmonella?
Yes, about 1/3 of eggs will be infected, but chicks hatch with the infection
How does pullorum disease spread?
Laterally
What clinical signs are associated with Pullorum disease?
Weakness, anorexia, chalky white feces, and death by 2-3 weeks
How is Pullorum disease prevented?
Purchase only pullorum-free birds and good biosecurity
How is Pullorum disease treated?
It is unwise to treat it -just euthanize and sanitize
What is the etiiologic agent of Fowl Typhoid?
S. enterica subspecies enterica serovar Gallinarum biovar gallinarum
How is fowl typhoid transmitted?
Horizontal and vertical transmission
What does fowl typhoid resemble in young birds?
Pullorum disease
What group of birds is fowl typhoid a serious problem in?
Growing and adult chickens and turkeys
Fowl typhoid has been eradicated from developed countries, but has been re-introduced on occasion to what farms?
Commercial poultry farms
What can happen to birds hatched from fowl typhoid infected eggs shortly after hatching?
they can die
What clinical signs do older birds with fowl typhoid exhibit?
Depression, dehydration, weight loss, watery to mucoid diarrhea, and anemia with pale shrunken combs
What lesions are associated with fowl typhoid?
Swollen, friable, bile-stained liver, splenomegaly, enlarged kidneys, and enteritis with bile-stained slimy contents
What enteric diseases need to be reported to the area veterinarian in charge or to the state veterinarian?
Pullorum disease and fowl typhoid
What is the treatment recommendation when fowl typhoid has been detected?
Quarantine and depopulation of infected flocks or extensive testing and removal of carriers
Where is Salmonella arizonae a problem and in what species?
It is a problem mostly in turkeys in some areas of North America
What is the mortality rate of Salmonella arizonae?
60%
What is the etiologic agent of ulcerative enteritis?
Clostridium colinum
What species get ulcerative enteritis?
Bobwhite quail, chickens, turkeys, pheasants, grouse, and other gallinaceous birds
What is ulcerative enteritis linked to?
Stress and other problems such as occidiosis and infectious bursal disease
What clinical signs are associated with ulcerative enteritis?
Diarrhea and thirst
What lesions are associated with ulcerative enteritis?
Enteritis and ulcers in the small intestine and upper large intestine
Peritonitis due to ruptured ulcers
Hepatitis and hepatic necrosis
How does Clostridia infect the liver in cases of ulcerative enteritis?
It enters the portal cicrulation
What does ulcerative enteritis look like in chickens?
Coccidiosis
How is ulcerative enteritis prevented?
Bacitracin in the water or feed
Streptomycin and Tylocin are also used
What causes Candidiasis, moniliasis, and thrush (they all the same thing just got many names)?
Candida albicans
What anatomic locations does candidiasis affect?
Mucosa of the mouth, proventriculus, intestines, cloaca, and gizzard
True or False: Candida albicans is the most common fungal pathogen of birds.
True
What population of birds does candidiasis affect?
Pet birds, commercial poultry that have been on antibiotics for long periods, chicks and poults around 1 month of age, and young layer hens
What is the epidemiology of Candidiasis?
Candida albicans is normal flora of the digestive tract. Outbreaks are often associated with poor sanitation and stress.
How is candidiasis spread?
Through waterers, feeds, and through litter
What clinical signs are associated with Candidiasis?
Nebulous, sick chick attitude, and a drop in egg production
What is sick chick attitude?
Poor growth rate and listlessness
What lesions does Candidiasis cause?
Thickened, white mucous membranes
White, raised plaques that tend to coalesce
How is Candidiasis diagnosed?
Gross lesions and histopath
What will you find on histpoath in patients with Candidiasis?
Yeast cells and pseudohyphae
How is Candidiasis prevented and controlled?
Avoid prolonged antibiotic therapy, good sanitation and disinfection with iodine, chlorination of water, copper sulfate, and Ca or Na proprionate in feed
How is Candidiasis treated in pet birds?
Oral nystatin
Ketoconazole or fluconazole in resistant infections
How is Candidiasis treated in poultry?
Copper sulfate in drinking water or Nystatin in feed or water with sodium lauryl sulfate
What is blackead also known as?
Histomoniasis
What is Blackhead?
A protozoan disease primarily of young turkeys 3-18 weeks of age and Peafowl
What is the characteristic lesion of Blackhead?
Cyanosis of the head (bluish discoloration)
What, other than turkeys, can carry Blackhead?
Chickens and wild birds
What is the etiologic agent of Blackhead?
Histomonas meleagridis
What is Blackhead transmitted/
H. meleagridis infects the eggs of cecal worms (Heterakis gallinarum) which are ingested by turkeys
Ingestion of infected earthworms also has been shown to cause infection
H. meleagridis an be transmitted directly through the cloaca from contaminated litter
Inside the cecal worm eggs, protozoa can remain infective for 2-3 ____ in soil.
years
What clinical signs are associated with Blackhead?
Acute, high mortality, sulfur-colored watery feces, cyanosis of the heat, anorexia, weight loss, depression, and emaciation
What organ is affected first by Blackhead?
Cecum
What lesions does Blackhead cause in the cecum?
Hemorrhage, inflammation, thickening and ulceration of the cecal wall, and dry, cheesy contents often streaked with blood
What lesions does blackhead cause in the liver?
Circular depressed areas, hepatomegally, and scarring
How is Blackhead treated?
Dimetridizole….. jk its banned by the FDA - there is no efficacious treatment approved by the FDA
How is Blackhead prevented?
Do not raise chickens and turkeys together or raise turkeys after the chickens have been in the same area
What is the etiologic agent of spotty liver disease?
Campylobacter hepaticus
Spotty liver disease is mostly a problem in what population of birds?
Free-range, barn raised flocks, layer operations
Where is C. hepaticus found in chickens with spotty liver disease?
The small intestine and cecum
How is spotty liver disease transmitted?
Fecal-oral
Spotty lifer disease is basically a _____ with 1-2mm ___ lesions.
hepatitis, liver
Does spotty liver disease affect egg production?
Yes - up to 35% reduction of egg production
What is the mortality rate of spotty liver disease?
Up to 15%
What species does erysipelas effect?
Turkeys
When does erysipelas commonly effect young tom turkeys?
When they are fighting or AI
When does erysipelas commonly affect hens?
4-5 days following AI - there are outbreaks of sudden deaths
Aside from AI and fighting, what else can spread Erysipelas?
Cannibalsism and ingestion of infected, dead birds
Can Erysipelas affect other species aside from turkeys?
Yes, serious outbreaks have occurred in chickens, ducks, and geese
How does Erysipelas usually present?
As an acute infection with sudden deaths
What clinical signs are associated with early cases of Erysipelas?
Depression and unsteady gait
What is the mortality rate of Erysipelas if unvaccinated?
50%
What is the mortality rate of Erysipelas if vaccinated?
15%
What lesion caused by Erysipelas usually results in no clinical signs and sudden death?
Vegetative endocarditis in turkeys
What lesions are associated with Erysipelas?
Generalized darkening or diffuse patchy darkening of the skin
Splenomegally and hepatomegally with occasional mottling
What differentials should be considered with Erysipelas?
Fowl cholera, Salmonellosis, E. coli, and Peracute Newcastle disease
How is Erysipelas diagnosed?
Culture of the liver, spleen, heart blood or bone marrow
How is Erysipelas prevented and controlled?
Immunization
How is Erysipelas treated?
Immunize with a killed bacterin and treat/prevent with potassium or sodium penicillin IM during an outbreak
Repeat immunization every 2-4 weeks (may be necessary to control)
Penicillin in the drinking water - only helps those still eating and drinking
What is Limberneck?
Botulism
Limberneck is a problem in what populations in the United States?
Wild duck populations in the Western U.S.
What botulism toxins result in Limberneck?
Most often type C, but also A, B, and F
How can birds get botulism?
In spoiled canned food, pond sediments, crustaceans, water insects, rotting vegetation, decaying carcasses, and maggots
True or False:Treatment of botulism is practical in most cases.
False - it is not practical in most cases
How can botulism be treated?
Antibiotics or for valuable birds Type C antitoxin
How is botulism prevented?
Prompt removal of dead birds, complete removal of litter, acidification of itter with acid disinfectants or sodium bisulfate, and/or immunization with toxoids in valuable birds
What is the main site of infection of Capillaria species?
the small intestine but there can be an infection in almost any area of the digestive tract
________ _______ is an intestinal parasite of pigeons, chickens, pheasants, and wild and domestic turkeys. It can be a problem in deep litter facilties.
Capillaria obsignata
What clinical signs are associated with Capillaria obsignata?
Diarrhea, weight loss, emaciation, decreased egg production, and pale birds
What lesions are associated with Capillaria obsignata?
Sever inflammation and thickening of the upper small intestine, occasional hemorrhage, erosion of the intestinal mucosa, and death if lesions are severe
How is Capillaria obsignata diagnosed?
Scrape intestinal mucosa and wash through a 100 mesh screen. Direct microscopic exam of mucosa may reveal worms in heavy infestations
Where does C. contorta occur?
In the crop and esophagus
What does C. contorta cause?
It may cause mucosal thickening and inflammation. Occasional severe losses in turkeys and game birds on the ground
What species is C. contorta most severe in?
Quail and pheasants
What clinical signs are associated with C. contorta?
Penguin stance due to pendulous crop, look of hunger at the feeder but won’t eat, emaciation, and swallowing motions
What lesions does C. contorta cause?
Thickened, inflamed walls of crop and esophagus, heavy exudate covers epithelium, and sloughing of epithelium
How is C. contorta diagnosed?
Masses of eggs and worms in sloughed epithelium or seen by pulling crop walls apart
How is C. contorta treated?
Hygromycin B is the best
Fenbendazole can work but it is not approved for use
Levamasole is quite effective
Vitamin A may help
What is the infective stage of poultry ascarids?
Eggs
What clinical signs do poultry ascarids cause?
Diarrhea, anorexia, weight loss, and intestinal blockage in heavy infestations
How are poultry ascarids prevented?
Clean, dry environment
How are poultru ascarids treated?
Pyrantel pamoate, piperazine, fenbendazole, and ivermectin
Supportive treatment if infestation is severe
_____ _____ is a poultry tick that is more common in warm climates and in backyard flocks. It is not common in commercial poultry facilities.
Argas persicus
What clinical signs are associated with Argas persicus infestation?
Anemia, skin lesions, occasional tick paralysis, emaciation, weakness, and reduced productivity
How is Argas persicus infestation treated?
It is more effective to use insecticide sprays in the buildings than to treat birds
________ _______ is the most common and economically significant louse.
Menacanthus stramineus
Where is poultry lice typically found?
on the breast, vent, and thighs
What do poultry lice do?
They puncture soft quills at their base gnaws the skin at the base and feeds on the blood
How can heavy populations of poultry lice affect flocks?
they can reduce reproductive potential and weight gain
How are poultry lice controlled?
Inseciticides treatment - repeat in 10 days
_________ _______ is the chicken mite, northern fowl mite, and tropical fowl mite.
Dermanyssus gallinae
________ is the turkey mite.
Trombiculidae
In what populations are poultry mites found?
breeeder and small farm flocks
True or False: Poultry mites are readily transmitted between farms and can remain in buildings for up to 6 months.
True
How are poultry mites treated?
Insecticide sprays or dusts
What is cannibalism often initiated by?
feather pecking
What issue exacerbates cannibalism?
crowding
What population is cannibalism more common in?
free-range chickens
What helps prevent cannibalism?
De-beaking and spectacles or blinders through the nasal septum
What predators are considered ‘one-a-day’ predators for poultry?
Raccoons, fox, coyotes, and hawks
What predators kill lots of poultry at a time?
Skunks and weasels
