Q&A: Stop piddling around with veterinary test results

Q: What can our clinical team do to get the most accurate results from a urinalysis?

Urinalysis is one of the simplest, most cost-effective diagnostic tests at our disposal, says Dr. Julie Byron, MS, DACVIM, a clinical assistant professor at The Ohio State University College of Veterinary Medicine. But practitioners should be aware of some misunderstandings about urinalysis, she says. Consider these misconceptions:

1. "It's OK to culture a free-catch urine sample." The results of a urine culture on a free-catch urine sample are really only useful if the culture is negative, Dr. Byron says. "If it's deemed positive, there need to be more than 100,000 cfu/ml of bacteria to consider it positive," she says. This also increases the incidence of culturing multiple organisms from the skin and distal urogenital tract.

2. "Storage of urine in the refrigerator shouldn't affect the result." Refrigeration of urine will lead to degeneration of casts and may lead to ex vivo crystal formation, both of which can affect diagnostic test accuracy, she says. Practitioners and their clinical teams need to be aware of these limitations.

3. "There's no need to examine a urine sediment in-house if I'm sending it off to a lab." See Myth No. 2 above. "Examining the urine before sending it out will prevent missing these elements," Dr. Byron says.