poultry immunosurpressive diseases

Question 1

what are the immune structures of the chicken

Answer 1

harderian gland
thymus
spleen
gut associated lymphoid tissue (GALT)
cecal tonsils
bursa of fabricus

Question 2

what are the three immunosurpressive diseases

Answer 2

infectious bursal disease
chicken anemia virus
mareks disease

Question 3

what kind of virus is infectious bursal disease and how many pathotypes are there

Answer 3

Birnaviridae, double stranded RNA nonenveloped.

4 groups of strains
mild
classical
very virulent
variant

Question 4

what is the process of IBDV

Answer 4

infection and destruction of B cells
leads to reduced number and function of plasma cells
leads to reduced antibody production
leads to increased susceptibility to other pathogens AND reduced response to vaccinations

Question 5

what are the clinical signs of acute IBD

Answer 5

depression
dehydration
muscular haemorrhage
proventricular and bursal haemorrhage

in mild cases lead to carcass condemnation and bursal atrophy

Question 6

how would you diagnose IBDV

Answer 6

necropsy, histopathology

serology (elisa, agar gel precipitation)

Question 7

how would you prevent IBDV

Answer 7

live vaccines!

drinking water, spray, ocular, nasal, subcutaneous, IN-OVO

Question 8

which immunosurpressive disease is a DNA Gyrovirus

Answer 8

CHICKEN ANEMIA VIRUS

Question 9

how is CAV transmitted

Answer 9

vertical

horizontal

Question 10

what structures does viraemia affect/destroy

Answer 10

thymus, spleen and bone marrow

Question 11

what group is this disease most often seen in

Answer 11

<7 days old chicks that are MDA negative

Question 12

what lesions are seen

Answer 12

thymus pale and atrophic
reduced bursa
BONE MARROW YELLOW!

Question 13

what are the clinical signs of CAV

Answer 13

haemorrhages under skin

anemic and weak

Question 14

how is the vaccination strategy for CAV different from other diseases

Answer 14

give live vaccines to breeders prior to egg production

chicks will have MDA’s against it then as a result

Question 15

What is the only tumor causing virus in chicken.

Answer 15

MARKES DISEASE

herpesvirus, oncogenic

Question 16

what is mareks disease classically associated with

Answer 16

nerve swellings and tumors!

Question 17

markes disease has an unique method of virus excretion. what is this

Answer 17

virus excreted through feather follicles.

inhaled by others

Question 18

what are the 4 manifestations of this disease

Answer 18

1. neurological
2. visceral
3. cutaneous
4. occular

(neurological=infiltration of the CNS and nerves resulting in
‘floppy broiler syndrome‘, transient paralysis of legs or wings and eye lesions.
Sciatic and brachial nerves affected)

Question 19

What is the characteristic position you find infected chickens in

Answer 19

on the floor with SPLAYED LEGS

Question 20

how is mareks vaccinated asgainst

Answer 20

Live vaccine given at day old

vaccine works through inhibition