Microscopic urine sediment examination, common in-clinic screening method for diagnosing urinary tract infections (UTI), is predictive of infection when coupled with urine culture and urinalysis bacterial results. It is only useful, however, when bacteria numbers in unstained urine are >10,000 rods/mL or >100,000 cocci/mL. The Accutest Uriscreen is a catalase-based test for detection of bacteriuria and pyuria. These enzymes are found in most bacteria that infect the urinary tract as well as within somatic cells. It is currently used as a screening test for UTI in humans, but has not been validated for use in dogs and cats.
In this study, 165 urine samples were evaluated for UTI based on bacterial culture, sediment evaluation, or Uriscreen. Twenty-seven samples were positive on bacterial culture; 24 of these tested positive with the Uriscreen. Of the 138 samples that cultured negative, 98 were negative on the Uriscreen (specificity, 71%). The Uriscreen was found to be more sensitive than sediment evaluation for the detection of UTI (89% vs 78%, respectively). False-positive results were common, but UTI was unlikely if results were negative. Limitations include the need for a urine culture and the potential for false-positive results caused by somatic cells in the absence of bacteria or presence of dysplastic cells.