DVM Preventive Medicine and Zoonoses 4

Question 1

Bovine tuberculosis (Mycobacterium bovis) is primarily controlled in US cattle herds through which regulatory program?

Accepted Answer

Federal-state cooperative test-and-slaughter program

Answer

The US bovine TB eradication program relies on the caudal fold tuberculin test (CFT) with slaughter of reactor animals and traceback investigations under federal-state cooperative authority.

Question 2

Which of the following zoonotic diseases is correctly matched with its primary animal reservoir in the United States?

Accepted Answer

Hantavirus pulmonary syndrome — deer mice (Peromyscus maniculatus)

Answer

Deer mice (Peromyscus maniculatus) are the primary reservoir for Sin Nombre virus, the agent of hantavirus pulmonary syndrome in the US.

Question 3

A sensitivity analysis on a diagnostic test reveals that at 85% sensitivity and 95% specificity, the positive predictive value (PPV) drops below 50% when disease prevalence falls below approximately:

Accepted Answer

8%

Answer

With 85% sensitivity and 95% specificity, PPV falls below 50% when prevalence drops below approximately 8%, illustrating how low prevalence dramatically reduces PPV.

Question 4

Marek's disease in poultry is best prevented through which approach?

Accepted Answer

Vaccination of day-old chicks in the hatchery combined with management practices

Answer

Vaccination of day-old chicks at the hatchery with herpesvirus of turkeys (HVT) or bivalent vaccines is the cornerstone of Marek's disease prevention, as the vaccine prevents tumor formation but not infection.

Question 5

Which of the following is the recommended approach for managing a confirmed Porcine Epidemic Diarrhea Virus (PEDV) outbreak on a naïve sow farm?

Accepted Answer

Controlled feedback of virus-containing material to non-pregnant gilts and sows to accelerate herd immunity

Answer

Controlled exposure (feedback) of non-pregnant animals to virus-containing material accelerates development of lactogenic immunity in sows before farrowing, protecting piglets through colostrum.

DVM - Doctor of Veterinary Medicine Practice Test

DVM - Doctor of Veterinary Medicine Practice Test

DVM Preventive Medicine and Zoonoses 4