Mortality & decreased egg production - poultry Flashcards
What are some non-pathological reasons for a drop in egg production?
Seasonality, broodiness, geriatric stock
What are some pathological causes of a drop in egg production?
Environmental stress
Flock mortality/morbidity
Malnutrition
Viral disease
Bacterial disease
Parasitic disease
What are the key components of investigating a drop in egg production and increased mortality?
History taking, clinical examination, post-mortem examination
What are the clinical signs of high-pathogenic avian influenza (HPAI)?
Anorexia
Up to 100% mortality in 36h
Respiratory signs (coughing, sneezing, swollen heads)
Nervous signs (depression)
Diarrhoea
What are the clinical signs of low-pathogenic avian influenza (LPAI)?
Anorexia
Respiratory signs (like HP)
Nervous signs
Diarrhoea
Egg production drop
Blood seen at nose and cloaca
What are the clinical signs of Newcastle disease in poultry?
What causes infectious bronchitis in poultry?
Coronavirus
What are the clinical signs of infectious bronchitis in poultry?
Snick (sneeze/cough)
Egg drop
Mortality
Huddling
Scouring
What are the common PM findings of infectious bronchitis in poultry & what further tests can be done?
Post-mortem findings: tracheitis, swollen kidneys (nephritis) , airsacculitis
Further tests: Serology, PCR testing, virus isolation
How can infectious bronchitis in poultry be treated & prevented?
Treatment: None, though antibiotics maybe appropriate if there are secondary bacterial infections
Prevention: Good terminal hygiene & appropriate vaccine
What causes avian rhinotracheitis?
Pneumovirus
2 subgroups:
- A (original UK isolate)
- B (original southern European isolate)
What are the clinical signs of avian rhinotracheitis?
Decreased appetite
Facial & head swelling
Ocular & nasal discharge
Conjunctivitis
Snick
Dyspnoea
Sinusitis
What are the common PM findings of avian rhinotracheitis & what further tests can be done?
Post-mortem lesions:
Serous rhinitis & tracheitis, pus in bronchi
Diagnosis:
Must differentiate from other respiratory diseases using serology, virus isolation & PCR
How can avian rhinotracheitis be prevented?
Vaccination with either Type A or B vaccine
What type of virus causes Infectious Laryngotracheitis?
Herpesvirus (lifelong latent infection)
What are the clinical signs of Infectious Laryngotracheitis?
Upper respiratory signs
Oedema of glottis, larynx
Plug of mucus
Periocular swelling
Sneezing
Tenosynovitis
Egg drop & reduced egg quality
How can infectious Laryngotracheitis in poultry be treated & prevented?
No treatment, antibiotics can help with secondary infections
Vaccination in commercial poultry
What are the clinical signs of Mycoplasma gallisepticum?
Mild sinusitis
Tracheitis
Airsacculitis
Egg drop
E coli infections often concurrent & result in severe air sac thickening, adhesive pericarditis & fibrinous perihepatitis
How can Mycoplasma gallisepticum be diagnosed?
PCR commonly used, culture is difficult, serology can be useful
How can Mycoplasma gallisepticum be treated and prevented?
Antibiotics reduce clinical signs, but don’t eliminate infection
Control with good biosecurity & good sourcing of stock
What bacteria cause Infectious Coryza?
Avibacterium avium
Why is Infectious Coryza significant in poultry flocks?
Severe respiratory disease
Poor response to antibiotics, no UK-licensed vaccines
Impact on egg production
Why is medication complicated in poultry?
Few licensed products
Need for careful antibiotic use
Withdrawal periods for eggs
Use cascade wisely
What analgesics are commonly used in poultry?
NSAIDs (meloxicam), aspirin, opioids (butorphanol preferred over buprenorphine)
What are the possible modes of treatment in poultry?
Individual application
In feed
In water
In ovo
What are the routes of administration for poultry vaccines?
Drinking water
Spray
Intra-ocular
In ovo
Injection
What other therapeutics are commonly used in poultry?
Vitamin supplementation
Analgesics & anti inflammatories
Competitive Exclusion Products (in ovo)
Yeast cell wall products
Organic acid products
Anthelmintics
Ectoparascides
What causes egg peritonitis?
Normal ovulation with oviduct failure to engulf ova, leading to egg yolk in coelomic cavity causing foreign body reaction
Common in laying hens
Prone to secondary infections
What are the clinical signs of egg peritonitis?
Lethargy
Stops laying
Upright posture
Weight gain with reduced appetite
Dirty around vent
What are the clinical signs of Avian Pathogenic Escherichia coli (APEC)?
Respiratory signs
Decreased appetite
Poor growth
Mortality
High morbidity
What are common post-mortem lesions of Avian Pathogenic Escherichia coli (APEC)?
Enteritis
Arthritis
Synovitis
Omphalitis
Salpingitis (inflammation of oviduct)
Peritonitis
Perihepatitis
Pericarditis
Airsacculitis
How is APEC diagnosed and prevented?
Culture, PCR
Vaccination available for breeders & layers
How is egg peritonitis treated?
Drain ascites
NSAIDs (egg withhold for 7 days)
Broad-spectrum antibiotics (if needed)
GnRH analogues (Suprelorin implant)
Spaying
