Effects of Diagnostic Work-Up on Medical Decision-Making for Canine Urinary Tract Infection: An Observational Study in Danish Small Animal Practices

Background: Clinical signs of urinary tract disease in dogs often lead to prescription of antibiotics. Appropriate diagnostic work-up could optimize treatment and reduce the risk of inappropriate use of antibiotics.

Hypothesis/objectives: To describe and evaluate the impact of diagnostic work-up on decision to treat (DTT) and choice of antibiotic treatment (COT) for dogs presenting with clinical signs of urinary tract disease.

Animals: One hundred and fifty-one dogs presenting to 52 Danish veterinary practices.

Methods: Prospective, observational study. Clinical signs, diagnostic work-up, and prescriptions were recorded. Urine samples were submitted to a reference laboratory for quantitative bacterial culture (QBC) and susceptibility testing. The laboratory results were used as reference for assessing the appropriateness of DTT and COT.

Results: In the majority of dogs, veterinarians performed dipstick (99%), microscopic examination of urine (80%) and bacterial culture (56%). Fifty-one percent of dogs had urinary tract infection (UTI) based on reference QBC. Appropriate DTT was made for 62% of the dogs, while 36% were over-prescribed and 2% under-prescribed. Inappropriate use of second-line agents was found in 57% of the UTI cases. Performing microscopy-but not culture-significantly impacted DTT (P = 0.039) while no difference was seen in COT (P = 0.67). The accuracy of in-house microscopy and culture were 64.5 and 77%, respectively.

Conclusions and clinical importance: Over-prescription of antibiotics was common among dogs with suspected UTI, regardless of the diagnostic work-up performed. Test inaccuracy under practice conditions and incoherence between diagnostic test results and decision-making both explained inappropriate and unnecessary use of antibiotics.