Evaluating the use of plasma hematocrit samples to detect ketones utilizing urine dipstick colorimetric methodology in diabetic dogs and cats

Objective: To determine whether plasma from a heparinized hematocrit tube placed on a urine dipstick would accurately reflect (positive or negative) urine ketone results in diabetic dogs and cats. Design: Prospective study, 37 dogs and 43 cats, with a known history of diabetes or hyperglycemia, glucosuria, and symptoms of undiagnosed diabetes mellitus were tested. Setting: Veterinary Referral Hospital. Animals: Client owned dogs and cats. Interventions: None. Measurement and main results: Heparinized plasma and urine ketone results were recorded using urine reagent strips. Plasma dipstick results were compared to urine dipstick results as the standard. Results were recorded based on the color chart provided by the manufacturer. Two individuals were responsible for verifying the results of the colorimetric test. Test efficiency was 97% (sensitivity = 96%, specificity = 100%) for the canine population, 93% (sensitivity = 100%, specificity = 83%) for the feline population, and 95% (sensitivity = 98%, specificity = 91%) for the total population. Four of 80 animals were found to have discordant results (1 dog and 3 cats). Conclusion: Plasma from heparinized hematocrit tubes is clinically useful for detecting the presence or absence of ketonuria, and therefore ketosis, in diabetic dogs and cats using urine dipstick colorimetric methodology.