Poultry Medicine: Infectious Disease Flashcards
Which drugs have no extralabel use in food-producing animal species?
How is colibacillosis diagnosed? What 6 postmortem findings are seen?
bacteriology –> E. coli
- air sacculitis and pneumonia
- enteritis
- septicemia
- synovitis, arthritis
- omphalitis
- coligranuloma formation
How is colibacillosis treated? Prevented?
antibiotics based on sensitivity - not typically recommended due to widespread resistance
- sanitation and disinfection
- biosecurity
What causes fowl cholera? Which poultry is most commonly infected? What acts as reservoirs?
Pasteurella multocida
young, mature free-range turkeys, chickens, ducks, and geese
chronically infected, asymptomatic carriers –> wild birds, cats, dogs, pigs, raccoons, insects
What signs are associated with acute fowl cholera?
- lethargy, poor condition
- anorexia
- mucoid discharge from nares/beak
- dyspnea
- cyanotic comb/wattle
- sudden death
What signs are associated with chronic fowl cholera?
- tracheal rales, dyspnea
- nasal/ocular d/c
- swelling of sinuses, wattles, leg or wing joints, foot pads, and sternal bursa
- toricollis
- decreased egg production
- stunted growth
How is fowl cholera diagnosed?
bacterial culture of oral/nasal mucus
What 4 postmortem findings are indicative of acute fowl cholera?
- general hyperemia with widespread petechial and ecchymotic hemorrhage, especially in the lungs, subserosa, and abdominal fat
- exudative pneumonia
- hydropericardium
- swollen liver with small, necrotic foci
What postmortem finding is indicative of chronic fowl cholera?
fibrinopurulent inflammation of respiratory tract, musculoskeletal system, and integument
What treatments are recommended for fowl cholera? How is it prevented?
- antibiotics - Sulfonamides decrease clinical signs and mortality
- acute form - prolonged IV antibiotics (10 days)
eliminate reservoir, good management practices, vaccine
What causes infectious coryza? What poultry are susceptible? How is it transmitted?
Avibacterium paragallinarum - highly contagious, acute respiratory disease with high morbidity and low mortality (secondary infections common!)
chickens of all ages - disease most severe in mature birds
direct through respiratory exudates or indirect through drinking water
What clinical signs are indicative of acute infectious coryza? Chronic?
- depression
- nasal discharge and sneezing - wiping exudate on wings/back
- conjunctivitis
- hyporexia, decreased water intake
- diarrhea
- stunted growth
- decreased egg production
dyspnea and facial edema
How is infectious coryza diagnosed? What postmortem findings are seen in acute and chronic cases?
swabs of exudate placed in commercial transport medium –> serology, culture, PCR (needs feeder bacteria to grow)
ACUTE - catarrhal (fibrinous rhinitis, conjunctivitis, sinusitis), SQ edema on face
CHRONIC - bronchopneumonia, air sacculitis
How can infectious coryza be prevented?
- IDEALLY - depopulation of infected/recovered flocks, cleaning and disinfecting, restocking 2-3 weeks
- vaccination
What causes Pullorum disease? How is it transmitted? What poultry is most commonly affected?
Salmonella pullorum –> almost eradicated, caused the formation of the National Poultry Improvement Plan
- vertically through infected hen through the egg
- horizontal
chicks and poults
What characteristic signs is seen in chicks with Pullorum disease?
chicks able to hatch are typically weak/depressed and have white diarrhea and dyspnea
- these chicks infect other birds in the flock
How is Pullorum disease treated? Prevented?
cull positive birds - antibiotics will not eliminate the pathogen
- careful sourcing of new birds from disease-free flocks
- good hygiene
What causes fowl typhoid? How is it transmitted?
Salmonella gallinarum
- vertical
- horizontal
- pests and fomites
What clinical signs are indicative of fowl typhoid in adults?
- depressed
- respiratory signs, dyspnea
- pale comb/watttle
- pyrexic
- weight loss
What 4 postmortem findings are indicative of fowl typhoid?
- septicemic
- catarrhal enteritis
- miliary necrosis of liver
- pericarditis
How is fowl typhoid treated? What is prognosis like?
- antimicrobials
- supportive therapy
- cull positive birds
fair - most survivors remain carriers
How is fowl typhoid prevented?
- good hygiene and biosecurity
- use serology and bacteriology to ID carriers
What is the most common cause of gangrenous dermatitis? What poultry is most commonly affected? How is it transmitted?
Clostridium perfringens
young, growing chicks - commonly secondary to immunosuppressive disease (prior infection with IBD)
fecla-oral
What are 2 classic signs of gangrenous dermatitis in poultry? What is seen on postmortem exam?
- legs/feet are hyperemic and swollen
- tissues of wing tip, medial thigh, and ventral wing become hyperemic and slough off
- dark, moist, edematous skin patches
- discoloration of underlying muscles
- swollen internal organs
How is gangrenous dermatitis treated? Prevented?
antibiotics or culling of infected birds to prevent spread (poor prognosis)
- good biosecurity and husbandry
- minimize stress
- control immunosuppressive disease
How is Mycoplasmosis transmitted?
- vertical
- horizontal - inhalation (direct), living vectors or fomites (indirect)
What causes chronic respiratory disease (CRD)? What poultry is most commonly affected?
Mycoplasma gallisepticum
chickens and turkey
What clinical signs are seen in cases of chronic respiratory disease of chickens and turkeys? What other complications are associated?
CHICKENS - air sacculitis (dyspnea)
TURKEYS - air sacculitis (dyspnea) + severe sinusitis
- poor hatchability - embryos with curled toes and dwarfism
- pericarditis
- perihepatitis
- peritonitis
What unique signs are associated with Mycoplasma synoviae infection?
- synovitis
- arthritis
- lameness
What poultry is most common affected by Mycoplasma meleagridis? How is it transmitted?
turkeys
vertical and horizontal –> present in bursa of Fabricius, phallus, oviduct, repro tract, and contaminated semen
What 4 clinical signs are associated with Mycoplasma meleagridis infection?
- air sacculitis
- decreased hatchability
- perosis, crooked neck, osteochondrodystrophy
- birds sick at time of hatching
How is Mycoplasmosis diagnosed? What 3 postmortem findings are indicative?
direct detection and ID on special media followed by biochemical differentiation, immunofluorescence, PCR, and antibody detection by serum plate agglutination, ELISA, and hemagglutination inhibition
- catarrhal - fibrinous rhinitis, sinusitis, tracheitis, bronchitis, air sacculitis
- pneumonia
- pericarditis, epicarditis with secondary E. coli infection
What treatment is recommended for Mycoplasmosis? What is prognosis like? How is it prevented?
antibiotics - Macrolides, Tetracyclines, Fluoroquinolones
good - nearly impossible to eliminate from a flock, recurrence common
provide optimal environment and nutrition + vaccine
What causes necrotic enteritis? What is it commonly secondary to?
Clostridium perfringens –> commensal in young growing broilers
- coccidiosis
- poor diet
- stress
- intestinal mucosal damage