DVM Trivia 5 — Questions and Answers
Question 1: What is the significance of the 'eclipse period' in the replication cycle of a virus?
- Time between infection and host immune response
- Period when no intact virions are detectable inside the cell (Correct answer)
- Time between host death and viral inactivation
- Duration of the carrier state
Correct answer: Period when no intact virions are detectable inside the cell
The eclipse period follows viral uncoating; the parental virus is dismantled and progeny virions have not yet assembled, so no intact virus particles are detectable.
Question 2: A ferret is presented with symmetrical alopecia, pot-bellied appearance, and pruritus. What is the most likely diagnosis?
- Hyperadrenocorticism (adrenal gland disease) (Correct answer)
- Hypothyroidism
- Sarcoptic mange
- Insulinoma
Correct answer: Hyperadrenocorticism (adrenal gland disease)
Adrenal gland disease (often adrenocortical carcinoma or adenoma) is extremely common in ferrets and causes sex hormone excess leading to bilateral alopecia and pruritus.
Question 3: Which test is the gold standard for antemortem diagnosis of bovine spongiform encephalopathy (BSE)?
- ELISA on serum
- Western blot on brainstem tissue (obex) (Correct answer)
- PCR on whole blood
- Histopathology of skeletal muscle
Correct answer: Western blot on brainstem tissue (obex)
BSE diagnosis requires Western blot (immunoblot) or immunohistochemistry detection of PrPSc in brainstem tissue, specifically the obex region.
Question 4: What is the primary action of atropine when used as a preanesthetic agent in dogs and cats?
- Muscle relaxation
- Reduction of salivary and respiratory secretions (Correct answer)
- Induction of sedation
- Prevention of vomiting
Correct answer: Reduction of salivary and respiratory secretions
Atropine is an anticholinergic that blocks muscarinic receptors, reducing secretions (saliva, mucus) and preventing bradycardia associated with anesthetic agents.
Question 5: Which protozoan parasite is transmitted transplacentally and causes abortion and neonatal neurological disease in cattle?
- Cryptosporidium parvum
- Neospora caninum (Correct answer)
- Sarcocystis cruzi
- Toxoplasma gondii
Correct answer: Neospora caninum
Neospora caninum is a leading cause of bovine abortion; it is transmitted vertically (cow to calf) in up to 95% of cases in endemically infected herds.
Question 6: A turtle is presented with open-mouth breathing, nasal discharge, and wheezing. What is the most likely class of pathogens causing upper respiratory tract disease in chelonians?
- Fungal (Aspergillus)
- Mycoplasma species (Correct answer)
- Spirochetes
- Protozoa
Correct answer: Mycoplasma species
Mycoplasma agassizii and M. testudineum are the primary agents of upper respiratory tract disease (URTD) in tortoises and sea turtles.
Question 7: What is the name for the surgical procedure that involves cutting the lateral digital extensor tendon to correct a knuckling over deformity in calves?
- Tenotomy of the superficial digital flexor
- Desmotomy of the suspensory ligament
- Tenotomy of the lateral digital extensor (Correct answer)
- Neurectomy of the palmar digital nerve
Correct answer: Tenotomy of the lateral digital extensor
In calves with spastic paresis or knuckling, tenotomy of the lateral digital extensor (and sometimes the tibialis cranialis) relieves the abnormal extensor tension.
DVM Trivia 5
What is the significance of the 'eclipse period' in the replication cycle of a virus?