FREE NAVLE Large Animal Herd Health Questions and Answers

Question 1

A dairy farmer reports a sudden increase in mastitis cases in his herd, with several cows exhibiting acute, severe clinical signs including fever, anorexia, and watery milk.
Milk culture results show a predominance of Klebsiella pneumoniae.
What is the most likely source of this outbreak?

Accepted Answer

Contaminated sawdust bedding

Answer

Poor milking machine hygiene

Answer

Inadequate post-milking teat dipping

Answer

Introduction of a new infected animal

Question 2

Which of the following management practices is most crucial for preventing the introduction and spread of Bovine Viral Diarrhea Virus (BVDV) in a beef cow-calf operation?

Accepted Answer

Testing all purchased replacement heifers for BVDV persistently infected (PI) status

Answer

Administering a modified-live vaccine to all calves at weaning

Answer

Implementing a strict external parasite control program

Answer

Ensuring adequate selenium supplementation in the feed ration

Question 3

A producer notices several lambs in his flock exhibiting lameness, swollen joints, and reluctance to move. Some lambs also have navel infections. The flock is housed indoors in a pen with deep bedding. What is the most likely causative agent for this presentation, and what is the primary route of infection?

Accepted Answer

*Trueperella pyogenes* via umbilical infection

Answer

*Erysipelothrix rhusiopathiae* via skin abrasions

Answer

*Streptococcus suis* via aerosol transmission

Answer

*Chlamydophila pecorum* via ocular secretions

Question 4

To effectively control internal parasites in a large ruminant herd, what is the most sustainable and recommended strategy to minimize anthelmintic resistance?

Accepted Answer

Implementing a 'targeted selective treatment' (TST) approach based on fecal egg counts or clinical signs

Answer

Administering anthelmintics to the entire herd at regular, fixed intervals

Answer

Rotating between different classes of anthelmintics every few months

Answer

Increasing the dose of anthelmintics to ensure complete parasite elimination

Question 5

A swine farmer reports an increase in stillbirths, mummified fetuses, early embryonic death, and respiratory disease in growing pigs. Serology reveals high titers to Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). What is the primary method of controlling PRRSV in a farrow-to-finish operation?

Accepted Answer

Strict biosecurity measures and management of pig flow (all-in/all-out)

Answer

Mass vaccination of all animals twice yearly

Answer

Antibiotic treatment of affected animals

Answer

Daily disinfection of all farrowing crates

Question 6

Which nutritional deficiency in pregnant ewes is most commonly associated with 'white muscle disease' (nutritional myodegeneration) in their lambs?

Accepted Answer

Selenium and Vitamin E

Answer

Iodine

Answer

Copper

Answer

Calcium

A dairy farmer reports a sudden increase in mastitis cases in his herd, with several cows exhibiting acute, severe clinical signs including fever, anorexia, and watery milk.Milk culture results show a predominance of *Klebsiella pneumoniae*.What is the most likely source of this outbreak?

A dairy farmer reports a sudden increase in mastitis cases in his herd, with several cows exhibiting acute, severe clinical signs including fever, anorexia, and watery milk.
Milk culture results show a predominance of Klebsiella pneumoniae.
What is the most likely source of this outbreak?