Mortality and decreased egg production

Question 1

Non-pathological reasons for egg drop

Answer 1

• Seasonality
• Hens have gone broody
• Geriatric stock

Question 2

Pathological reasons for egg drop

Answer 2

• Environmental stress
• Flock mortality/morbidity
• Malnutrition
• Viral disease
• Bacterial disease
• Parasitic disease

Question 3

Name some viruses that could cause egg drop

Answer 3

• Avian influenza (low pathogenic virus infection)
• Newcastle disease
• Infectious bronchitis (caused by a coronavirus)
• Infectious laryngotracheitis (caused by herpesvirus)
• Avian rhinotracheitis (originally caused by Type A virus in the UK)

Question 4

Name some bacterial infections that could cause egg drop

Answer 4

• Mycoplasma gallisepticum
• Infectious coryza (Avibacterium avium)

Question 5

Egg peritonitis

Answer 5

Egg yolk in the coelomic cavity leading to a foreign body reaction.

Question 6

Answer 6

Infectious laryngotracheitis

Question 7

Answer 7

Egg peritonitis

Question 8

Treatment options for egg peritonitis

Answer 8

• Drain the ascites → perform cytology/culture
• Consider an NSAID off-licence
• Antibiotic: not always necessary. Ideally base choice on culture; if this is not possible, try a broad spectrum option e.g. TMPS

Question 9

How could you diagnose APEC?

Answer 9

Avian pathogenic E. coli

Culture or PCR

Question 10

Pathogenesis of egg peritonitis

Answer 10

• Caused when normal ovulation occurs but the oviduct fails to engulf the ova
• The egg yolk in the coelomic cavity causes a foreign body reaction
• This can produce a sterile ascites, but the bird is often prone to secondary infections e.g. E. coli

Question 11

Possible pathogenesis of salpingitis

Answer 11

• Ascending infection from a contaminated cloaca
• Translocation from respiratory system
• Translocation from intestine

Question 12

Clinical signs of egg peritonitis

Answer 12

• Lethargy
• Stops laying
• Upright posture
• Weight gain with reduced appetite
• Dirty around vent

Question 13

Swollen head syndrome refers to which condition?

Answer 13

Avian rhinotracheitis

Question 14

Clinical signs of avian rhinotracheitis

Answer 14

• Decreased appetite
• Facial and head swelling
• Ocular and nasal discharge
• Conjunctivitis
• Snick
• Dyspnoea (see image)
• Sinusitis