Poultry Forensics

Question 1

Origin of Avian Leucosis?

Answer 1

§ Clinical signs only in case of infection before the age of 10 weeks

§ If the animals are over 10 weeks of age at time of delivery: it is originated back before

delivery

§ If the animals are under 10 weeks of age at time of delivery: either germinative or

contact infection, before the age of 10 weeks: epidemic investigation

Question 2

Significance of Avian leukosis?

Answer 2

§ Sporadic deaths

§ Breeding flock: germinative infection

§ Always significant (even 1 case)

§ Immuno-tolerance: life-long virus shed

§ Table egg production: if death rate is over 2%

Question 3

Origin of Derzsy´s disease?

Answer 3

High rate of death: germinative infection or infection at the hatchery

§ Incubation period: 8-12 days

§ Serum on the first day at the hatchery

§ Isolation of the day-old chickens

§ Vaccination of breeding flocks

Question 4

Significance of Derzsy’s disease?

Answer 4

Breeding flock: germinative infection

§ Broiler flock: if the loss is over 2%

Question 5

Origin of Mushy chicken disease?

Answer 5

Death of day-old chickens under the age of 10 days can be originated back to the hatchery (or
to the breeding flock)

Question 6

Diagnosis of Mushy chicken disease?

Answer 6

Clinical signs: weak, low body weight (minus variants)

§ Pathological findings: triad: yolk sac persistence, omphalitis, improper closing of the

navel

§ Mortality: 1-10 days

§ Laboratory examinations: excluding other infectious and non-infectious diseases

Question 7

Origin of Fowl typhoid?

Answer 7

Death during the first 5 days could be originated back to the hatchery

§ To the breeding flock: if the hatchery complied with the rules (marking the eggs,

separate hatching)

§ Tests: blood tests, examination of dead eggs

§ Deaths after 5 days of age: epidemic investigation (isolation etc.)

Question 8

Significance of Fowl typhoid?

Answer 8

Infection: significant in breeding flocks
§ Disease: broiler chickens: death rate (2%)
§ Breeding flocks: germinative infection (even 1 case could be significant)

Question 9

Origin of Fowl cholera?

Answer 9

§ Virulent P. multocida (carrier) and predisposing factors
§ Clinical signs within 24 hours: could be originated back before the time of delivery
§ After 24 hours: was there any fowl cholera outbreak at the seller during the previous 1
year (carrier state)?
§ Has he informed the buyer about the previous outbreak?
§ Other source of infection at the buyer (isolation, all in-all out system?)
§ Predisposing factors (transport, force-feeding etc.)

Question 10

Significance of Fowl cholera?

Answer 10

Depending on rate of death eggshell contamination, but there is no germinative transmission

Question 11

Significance of Marek´s disease?

Answer 11

Depending on death rate (2%)

§ No germinative infection

Question 12

Origin of Marek´s disease?

Answer 12

§ Age of susceptibility (10 weeks of age)

§ Routes of infection: eggshell, day-old chickens, adult poultry, equipment, persons)

§ Incubation period (1-7 months)

§ The younger is the chicken the higher is the susceptibility

§ High rate of diseased animals: if infection during the first days of life

§ Infection at the hatchery: if isolation until the age of 6-8 weeks

Question 13

Fertility of the eggs?

Answer 13

Sex-rate
§ Age
§ Temperature
§ Length and intensity of lighting
§ Infectious and non-infectious diseases
§ Feed-toxicosis

Question 14

Hatchability of the eggs?

Answer 14

Age of the egg

§ Contamination

§ Temperature and humidity during storing

§ Transport

§ Rest after transport

§ Vitamin supply

§ Hatching technology