Affordable in-house tests for bacteriuria can improve antimicrobial stewardship and access to care

OBJECTIVE To evaluate the clinical utility of 3 in-house tests to screen for bacteriuria in dogs with urinary conditions: a computerized urine sediment analyzer (SediVue), a rapid immunoassay (RapidBac), and in-house urine culture. Accuracy of culture and antimicrobial susceptibility (C&S) results from submission of the positive in-house culture plate and a 24- to 48-hour refrigerated urine sample was also assessed. METHODS Sterile urine samples from 101 client-owned dogs were used to evaluate sensitivity, specificity, positive predic- tive value, and negative predictive value of 3 in-house diagnostic tests to detect bacteriuria using C&S testing at a reference laboratory as the reference standard. For positive in-house culture plates, the plate and a 24- to 48-hour refrigerated urine sample were submitted to the reference laboratory for C&S testing and compared to the reference standard. RESULTS The reference standard C&S was positive in 25 of 101 cases (25%). All 3 in-house diagnostic tests had high negative predictive values: SediVue was 89% (95% CI, 81% to 96%), RapidBac was 93% (95% CI, 88% to 99%), and in-house culture was 99% (95% CI, 96% to 100%). Positive predictive values were 89% (95% CI, 74% to 100%) for SediVue, 77% (95% CI, 61% to 93%) for RapidBac, and 86% (95% CI, 73% to 99%) for in-house culture. Culture and antimicrobial susceptibility results from submission of the positive in-house plates and refrigerated urine samples approximated the reference standard. CONCLUSIONS SediVue, RapidBac, and in-house cultures performed well to rule out canine bacteriuria. CLINICAL RELEVANCE Inexpensive in-house diagnostic tests can be used to screen for bacteriuria prior to submission of C&S testing, which promotes antimicrobial stewardship, responsible use of client resources, and access to veterinary care.