Diseases of commercial chickens Flashcards
What are immunosuppressive diseases of growers + pullet chickens?
- Infectious bursal disease virus
- Chicken anaemia virus
- Marek’s disease
- Reoviruses
- Mycotoxicosis - non-infectious
What are respiratory diseases of growers + pullet chickens?
- Mycoplasmas
- IBV
- aMPV / SHS
- ILT
- NDV
- AIV
- E coli
- P multocida
- Ornithobacterium
- Infectious Coryza
What are CS of ornithobacterium rhinotracheale? Dx? Tx?
- Coughing/ sneezing
- Reducing weight gain, poor FCR
- Reduced egg production
- Main lesions = airsacculitis, tracheitis, bronchopneumonia
- Dx = culture + PCR
- Tx = antibiotics, vaccine
What are gastroenteteric problems of grower + pullet chickens?
- Salmonella
- E coli (ETEC)
- Clostridium
- Campylobacter
- Parasites / worms / protozoa
- Crop mycosis
What are clinical signs of clostridium enteritis? Dx? Tx?
- Acute form in young chickens
- Depression, ruffled feathers, sudden death, increased mortality
- Poor weight gain + FCR
- Necrosis of intestinal mucosa, fibrinonecrotic enteritis forming diphtheritic membrane
- Dx = signs, lesions, culture + PCR
- Tx = antibiotics
What are nervous system problems in grower + pullet chickens?
- Avian encephalomyelitis
- Marek’s disease
- Botulism
- Nutritional encephalomalacia
- NDV
- AIV
What is Avian encephalomyelitis? Dx? Tx? Px?
- Picornavirus
- Tremor of head + neck, legs, paralysis, cataract
- Drop in egg production
- Dx = histopath, PCR
- Tx = NONE
- Px = vaccine
What are non-infectious causes of lameness in grower / pullet chickens?
- Tibial dyschondroplasia
- Spondylolisthesis
- Rickets
- Valgus-varus deformities
- Ionophore toxicity
What are infectious causes of lameness in grower / pullet chickens?
- Marek’s disease
- Botulism
- Bumblefoot
- Viral arthritis
- Infectious synovitis
- Staphylococcus / other septic arthritis
What is dyschondroplasia influenced by?
- Affects proximal tibiotarsus- tibial dyschondroplasia
- Influenced by
- genetic selection
- feed: calcium/phosphorus ratios
- acid:base balance in feed
- mycotoxins
What causes rickets?
- Calcium, phosphorus or vitamin D deficiency
What are respiratory problems that affect layer hens? (drop in egg production)
- Mycoplasmas
- IBV
- aMPV / SHS
- NDV
- AIV
- P multocida
- Infectious Coryza
- Brachyspira spp infection
What causes peritonitis in layers? What are influencing factors?
- Mainly E. coli
- influencing factors =
- flock uniformity
- body weight
- physical + hormonal stresses
- source of bacteria = water/ air
Peritonitis can be secondary to what infections?
- M synoviae
- P multocida
- Erysipelas
- ORT
- IBV
- aMPV
- NDV
- AIV
How can peritonitis be treated / prevented?
- Tx = antimicrobial therapy + E coli vaccination
- Px = E coli vaccination, minimise bacterial challenges, reduce stress + sustain body weight + uniformity
