CVA Laboratory Techniques and Diagnostic Procedures 5

Question 1

When preparing a bacterial culture swab from a wound, which transport medium is most appropriate to maintain organism viability during shipping?

Accepted Answer

Amies or Stuart transport medium

Answer

Amies and Stuart transport media maintain moisture and preserve bacterial viability without allowing significant growth or drying during transit to the lab.

Question 2

A BUN (blood urea nitrogen) to creatinine ratio greater than 20:1 in a dehydrated dog most likely indicates what type of azotemia?

Accepted Answer

Pre-renal azotemia due to reduced renal perfusion

Answer

Pre-renal azotemia causes disproportionate BUN elevation relative to creatinine because the kidney reabsorbs urea more avidly when perfusion is low, raising the BUN:Cr ratio above 20:1.

Question 3

Which type of microscope objective is used to identify microfilariae in a modified Knott's test preparation?

Accepted Answer

Low power (10×)

Answer

The 10× objective (low power) is used first to scan for microfilariae because they are large enough to be visible at low magnification and are easier to find across the field.

Question 4

What does the term 'isosthenuria' mean in the context of a urinalysis?

Accepted Answer

Urine specific gravity equal to that of glomerular filtrate (1.008–1.012), indicating tubular inability to concentrate or dilute

Answer

Isosthenuria (USG 1.008–1.012) means the kidney can neither concentrate nor dilute urine beyond plasma ultrafiltrate, signaling severe tubular dysfunction.

Question 5

A Diff-Quik stained impression smear from a skin lesion reveals numerous round organisms with a clear halo inside macrophages. What is the most likely organism?

Accepted Answer

Cryptococcus neoformans

Answer

Cryptococcus neoformans appears as round yeast with a prominent clear polysaccharide capsule (halo) and is commonly found inside macrophages on cytology.

(CVA) Certified Veterinary Assistant Practice Test

(CVA) Certified Veterinary Assistant Practice Test

CVA Laboratory Techniques and Diagnostic Procedures 5