Poultry Flash - Newcastle Disease

Question 1

what are the 5 forms of newcastle disease? which ones are reportable?

Answer 1

1. viscerotropic velogenic - reportable
2. neurotropic velogenic - reportable
3. mesogenic - reportable
4. lentogenic - not reportable, used for MLV
5. asymptomatic enteric - not reportable

Question 2

what is the classic presentation of the viscerotropic velogenic form of newcastle disease?

Answer 2

highly virulent, 100% mortality in 2-3 days

respiratory - gasping, coughing, wheezing, sneezing, nasal discharge, square head from facial edema

neurologic - tremors, droopy wings, opisthotonus, circling, paralysis, torticollis

gi - digestive inappetence, violent watery green diarrhea

repro - decreased egg laying, thin shells, abnormal shapes

sudden death

Question 3

what clinical signs are seen in the neurotropic velogenic form of newcastle?

Answer 3

highly virulent 100% morbidity with 50% mortality

respiratory signs followed by neurologic signs

Question 4

what clinical signs are seen in the mesogenic form of newcastle?

Answer 4

moderate virulence & low mortality

young - up to 50% mortality, gasping, coughing, hoarse chirping, ataxia, & star gazing

adults - mild depression, respiratory signs, increased morbidity due to secondary infections, decreased egg production, & abnormal eggs

Question 5

what is seen on necropsy of a bird with the viscerotropic velogenic form of newcastle?

Answer 5

hemorrhage & necrosis of lymphoid organs, depletion of lymphoid tissue

Question 6

what is seen on necropsy of a bird with the neurotropic velogenic form of newcastle?

Answer 6

no gross lesions!!!

lymphoid depletion, myocarditis, CNS gliosis

Question 7

what is seen on necropsy of a bird with the mesogenic form of newcastle?

Answer 7

thickened air sacs, tracheal/pulmonary hemorrhages, brainstem encephalitis, myocardial/splenic/pancreatic necrosis

Question 8

what is the gold standard test for newcastle disease?

Answer 8

virus isolation

Question 9

what test, if positive for newcastle, is notifiable?

Answer 9

positive hemagglutination activity = newcastle or avian flu specific amino acid motif of F protein

Question 10

what test is widely used for measuring virulence of newcastle disease?

Answer 10

ICPI - intracerebral pathogenicity index - most sensitive

Question 11

what treatment is used for newcastle disease?

Answer 11

none - cull all birds on premises of outbreak

Question 12

how is newcastle disease prevented?

Answer 12

vaccinate - but doesn’t full protect

strict biosecurity & sanitation protocols

Question 13

if a strain is positive for hemagglutination activity, what disease of chickens is ruled out?

Answer 13

rules out infectious bronchitis