Poultry diseases Flashcards
Type 3 Coronavirus disease
Infectious bronchitis
True or false.
Infectious bronchitis is caused by an RNA virus.
What significance does this have?
True - coronavirs
RNA viruses have fast mutation rates when compared with DNA viruses
Transmission of infectious bronchitis
Aerosol transmission - easily infecting the entire shed in an indoor broiler flock
What clinical signs are associated with infectious bronchitis in:
- Broilers
- <6 weeks broilers
- Layers
- Misc
- Broilers - Respiratory dz, wt loss
- Young - Depressed, huddled, nephritis
- Layers - Small and poor functioning oviducts (poor egg quality), respiratory signs
- Other - renal and gut (mutated virus)
Which strain of Infctious Bronchitis Virus causes abnormal oviduct development in layers?
M41
Egg peritonitis can be a sequelae to which viral disease?
Infectious bronchitis - M41 strain
What diagnostic tools are used in assessing potential cases of IBV?
Virus isolation (from eggs), PCR (genotype), serology
What types of vaccines are used in control of IBV?
Live attenuated in broilers
Live attenuated and killed in breeders
A paramyxovirus causing severe respiratory disease in turkeys and mild in other avian species.
Avian metapneumonia virus
What clinical signs are associated with aMPV in turkeys?
- Nasal discharge
- Sinusitis
- SBI - E.coli
- Decreased egg production and quality
- Mortality
Swollen head syndrome
Oedematous facial tissues associated with aMPV and E.coli infection

aMPV shows more severe clinical signs in turkeys or chickens?
Turkeys
Loss of pigmentation of egg shells is associated with which pultry respiratory disease?
aMPV
Outline the methods of transmission of aMPV
Horizontal - aerosol, mucus, fomites
Vertical - egg transmission(+/-)
How can aMPV infections be controlled/ prevented?
- Prevent it entering the farm - all-in-all-out, biosecurity, housing ventilation and temperature
- Increase flock resistence - vaccination
- Live - for broilers
- Killed before lay
Which Mycoplasma bacteria are associated with disease in poultry?
What type of disease are they associated with?
- Gallisepticum - Respiratory
- Synoviae - Respiratory and arthritis
- Meleagridis - Turkey airsaculitis
What respiratory signs are associated with Mycoplasmal disease in poultry?
Nasal discharge
Cough
Sneeze
Tracheal rales
Swollen watery eyes
Decreased wt gain
May cause sinusitis/ conjunctivitis
What reproductive signs are associated with mycoplasmal disease in poultry?
Decreased egg production
Delayed point of lay - salpingitis
Dead in egg
Decreased hatchability/ survivability
What musculoskeletal signs are associated with mycoplasmal disease in poultry?
Lameness
Swollen joints
Sternal bursitis
Decrease wt gain
Loss of condition
What is the gold standard diagnostic test for mycoplasmal disease in poultry?
What alternative may be employed?
Culture! BUT it takes a long time!
PCR may be used but this detects both viable and non-viable infectious agents (live and dead)
High pathogenicity strains of Avian Influenza
H5 & H7
What poultry diseases are notifiable in the UK?
- Avian influenza
- Newcastle disease
Incubation period of avian influenza
hrs - 3 days in individual birds
14 days in flock
Transmission of avian influenza
Faeco-oral
Fomite
Pathogenesis of avian influenza.
Replication, necrosis, congestion and haemorrhage of GI and respiratory tissues.
What clinical signs are associated with avian influenza?
- General - dull/ depressed, anorexia, cyanotic wattle, swollen head
- GI - d+, pasty vent, organ necrosis
- Resp - tears, sneeze, dyspnoea, nasal discharge
- Uro/repro - decreased egg yield
- Neuro - severe
- Other - emaciation
What post mortem lesions are associated with avian influenza?
- General - haemorrhage, cyanosis, periorbital oedema
- GI - Firm/ mottled haemorrhagic pancreas, spleen necrosis
- Resp - Sinusitis, tracheitis
- U/R - Oviduct inflammation, nephromegaly
- Other - peritonitis/ pericardial haemorrhage
Name two reportable diseases found in poultry.
Brucellosis
Salmonellosis
Name five poultry diseases that are zoonotic.
Campy
Crypto
E. coli
Listeriosis
Psittacosis
Salmonellosis
Which species of salmonella are associated with disease in poultry?
Salmonella enterica sbspp. typhimurium/ enteritidis
Transmission of avian tuberculosis.
Faecal-oral
Progressive wt loss, depression, diarrhoea, death
Which species of Chlamydia is associated with disease in poultry?
Chlamydia psittaci
Causes respiratory disease and diarrhoea
Fowl typhoid
Salmonella gallinarium
Pullorum disease
Salmonella pullorum
Paratyphoidal disease and Salmonellosis
Salmonella Enteritidis
Salmonella Tymphimurium
Why is Salmonellosis a significant disease despite not causing significant economic loss for poultry producers?
Causes severe gastroenteritis, nausea, v/d and fever in humans
May lead to death if left untreated
Name three Coccidial parasites associated with disease in poultry.
Eimeria…
- Acervulina
- Brunetti
- Maxima
- Mitis
- Necatrix
- Praecox
- Tenella
Name three Anticoccidial agents used in chickens.
- Chlorotetracycline
- Oxytetracycline
- Baycox
- Sulfamethazine
- Sulfadimethoxine
Name an attenuated and non-attenuated coccidial vaccine used in poultry.
Attenuated - Paracox
Non-attenuated - Coccivax
Vaccines in poultry can be administered by what methods?
Spray
Drinking water
On-food
Injectable
Injectable vaccines are used in control of which poultry disease?
Mareks
Poultry circovirus
Chicken anaemia virus
Transmission of chicken anaemia virus.
Vertical
Horizontal - faeco-oral, feather follicles
What clinical signs are associated with Chicken Anaemia Virus?
- Ab -ve at 12-17 do
- Anorexic, weak, depressed
- Decreased PCV, anaemia, leukopenia, pan-cytopenia
- No response to vaccine
- SBI
What PM lesions are associated with chicken anaemia virus infection?
Decreased lymhoid tissue - thymus and bursa of fabricious
Pale and yellow marrow
Dermal, muscular and visceral haemorrhage
Avibinavirus aka Gumboro disease
Infectious bursal disease
Transmission of IBDV
Faecal-oral
Signs of acute IBDV
- Sudden onset
- Depression
- Ruffled feathers
- Vent pecking
- 90%+ mortality
- Dehydration
- Muscular and bursal haemorrhage
Signs of high virulence IBDV
+++ mortality
Fibrosis, haemorrhage and destruction of muscle, proventriculus, bursa
Oedematous and haemorrhagic lesions
MALT organs affected
Subclinical IBDV
Bursal atrophy
GaHV-2 oncogenic viral disease in poultry
Mareks disease
Signs of classical Mareks disease.
Limb paresis
Dyspnoea
Crop dilation - CN X
Dermal, muscular and visceral tumours
Grey eye
Mareks disease virus - lymphocytic infiltration
Mareks disease transmission
Feather follicle shedding
Notifiable paramyxovirus affecting poultry
Newcastle Disease
Name the five types of Newcastle disease.
Which is the most severe?
- VV - viscerotropic-velogenic
- NV - neurotropic-velogenic
- M - mesogenic
- L - lentogenic
- A - assymptomatic enteric
VV NDV
Acute, lethal infection
GI haemorrhage
NV NDV
Respiratory and neurological signs, no gut lesions, high mortality
M NDV
Lower mortality respiratory an neurological disease than NV
L NDV
Mild respiratory disease
A NDV
Assymptomatic enteric disease
Transmission of NDV
Direct contact
Contact with contaminated secretions
Clinical signs associated with NDV
- General - anorexic, dehydrated, poor condition
- Neuro - tremors, star-gazing, twisted neck, convulsions, paralysis
- Respiratory
- Visceral - Green-yellow diarrhoea, intestinal haemorrhage