NAVLE Swine Medicine and Production

Question 1

A commercial sow farm reports a sudden increase in late-term abortions, stillbirths, and weak-born piglets across multiple farrowing rooms.
Serology confirms Porcine Reproductive and Respiratory Syndrome Virus (PRRSV).
Which viral characteristic best explains the reproductive failure observed?

Accepted Answer

PRRSV infects porcine alveolar macrophages and spreads hematogenously to the fetoplacental unit during the last trimester

Answer

PRRSV preferentially infects uterine endometrial cells, causing direct placental necrosis

Answer

PRRSV crosses the placenta during early gestation and integrates into fetal DNA

Answer

PRRSV causes reproductive failure exclusively through induction of hyperprogesteronemia

Question 2

A nursery pig presents with acute onset of polyarthritis, meningitis, and sudden death. Gram-positive cocci in pairs and short chains are isolated from CSF. What is the most likely causative organism?

Accepted Answer

Streptococcus suis serotype 2

Answer

Erysipelothrix rhusiopathiae

Answer

Haemophilus parasuis

Answer

Mycoplasma hyorhinis

Question 3

Postweaning multisystemic wasting syndrome (PMWS) associated with Porcine Circovirus type 2 (PCV2) is diagnosed in a 6-week-old pig. Which histologic lesion in lymph nodes is considered pathognomonic?

Accepted Answer

Lymphoid depletion with histiocytic replacement and intracytoplasmic basophilic inclusion bodies

Answer

Lymphoid hyperplasia with germinal center formation

Answer

Lymphocytic vasculitis with fibrinoid necrosis

Answer

Granulomatous lymphadenitis with central caseation

Question 4

A gilt in a farrow-to-finish operation develops diamond-shaped, raised, red skin lesions over the trunk 2 days after moving to the breeding barn. The most appropriate treatment is:

Accepted Answer

Penicillin G IM, NSAIDs, and isolation

Answer

Florfenicol IM and supportive care

Answer

Ivermectin SC and topical antifungal

Answer

Enrofloxacin IM and corticosteroids

Question 5

Which of the following is the recommended nutritional strategy to prevent osteochondrosis dissecans (OCD) in fast-growing market pigs?

Accepted Answer

Ensuring Ca:P ratio of approximately 1.2:1 with adequate vitamin D and controlled growth rate

Answer

High-calcium, low-phosphorus diet to maximize bone density

Answer

Restricting dietary lysine to slow growth rate

Answer

Supplementing vitamin E and selenium to prevent oxidative cartilage damage

Question 6

Transmissible Gastroenteritis (TGE) and Porcine Epidemic Diarrhea (PED) cause clinically identical disease but differ in one key epidemiological feature. Which statement correctly distinguishes them?

Accepted Answer

Both are coronaviruses, but TGE has largely been displaced in North America by PEDV since its 2013 emergence

Answer

TGE is caused by a coronavirus while PED is caused by a rotavirus

Answer

PED virus does not infect adult swine, while TGE virus affects all ages equally

Answer

TGE causes bloody diarrhea while PED causes watery white diarrhea with no blood