Relationship between Urine Protein-To-Creatinine Ratio and Leukocyte Esterase in Canine Urine Samples

The urine dipstick strip test is used for detecting urinary leukocytes and protein; however, factors like specific gravity, pH and infection may affect accuracy. Concerns exist regarding white blood cells interfering with the urine protein-to-creatinine (UP/C) ratio, a key test for proteinuria.

This study aimed to determine whether the results of the leukocyte esterase test affect the UP/C ratio in canine urine samples.

A total of 186 canine urine samples were collected. The dipstick strip leukocyte esterase test was used to classify the specimens into two groups: leukocyte strip-positive (+) and leukocyte strip-negative (-). The UP/C ratio was then measured for all samples employing the Catalyst One biochemical analyser.

The absolute value of the correlation coefficient between leukocyte strip status (±) and the UP/C ratio was 0.014 (p = 0.849), indicating no significant correlation. When applying the International Renal Interest Society (IRIS) grading criteria and setting the threshold for abnormal UP/C at ≥ 0.2, no significant correlation was found between leukocyte strip status and abnormal UP/C (p = 0.490). When categorising the UP/C ratio according to IRIS classification criteria, the absolute value of the correlation coefficient between leukocyte strip status and UP/C classification was 0.032 (p = 0.661), again showing no association. These findings suggest that a positive leukocyte esterase test does not interfere with the UP/C ratio.

The presence of a positive leukocyte esterase test does not affect the UP/C ratio in canine urine samples. Therefore, the UP/C ratio test can be performed regardless of the results of the leukocyte esterase test.