Clinical Laboratory Procedures Flashcards

What is the normal packed cell volume (PCV) range for adult dogs?

Answer: 37–55%

The normal PCV (hematocrit) for adult dogs is approximately 37–55%, with values below 37% indicating anemia.

A cat's blood smear shows many erythrocytes with refractile inclusions near the cell membrane that stain blue with new methylene blue. This is MOST consistent with:

Answer: Heinz bodies

Heinz bodies are aggregates of denatured hemoglobin that stain with supravital stains like new methylene blue and are common in cats due to their susceptibility to oxidative damage.

When collecting a urine sample by cystocentesis, which needle gauge and direction is most appropriate?

Answer: 22-gauge needle, directed into the bladder body

A 22-gauge needle directed into the body of the bladder is standard for cystocentesis to minimize trauma and obtain a sterile sample.

Which chemistry value would you expect to be ELEVATED in a patient with cholestasis?

Answer: Alkaline phosphatase (ALP)

ALP is an enzyme that leaks from biliary epithelial cells during cholestasis, making it a key marker of bile duct obstruction or hepatobiliary disease.

In a complete urinalysis, crystals identified as colorless coffin-lid shaped structures are most likely:

Answer: Struvite (magnesium ammonium phosphate)

Struvite crystals classically appear as colorless three-to-six-sided 'coffin-lid' prisms and are common in alkaline urine.

Which of the following is a zoonotic disease that can be detected on fecal examination?

Answer: Toxoplasma gondii oocysts in cat feces

Toxoplasma gondii oocysts shed in cat feces are infectious to humans, especially immunocompromised individuals and pregnant women.

A blood sample is hemolyzed when received at the laboratory. Which chemistry value is MOST likely to be falsely elevated due to hemolysis?

Answer: Potassium

Potassium is found in high concentrations inside red blood cells, so hemolysis releases intracellular potassium and artificially elevates serum potassium.