Canine UTI Diagnostics and Treatment in Denmark

May 25, 2018
Natalie Stilwell, DVM, MS, PhD

Dr. Natalie Stilwell provides freelance medical writing and aquatic veterinary consulting services through her business, Seastar Communications and Consulting. In addition to her DVM obtained from Auburn University, she holds a MS in fisheries and aquatic sciences and a PhD in veterinary medical sciences from the University of Florida.

According to a recent study, suspected cases of urinary tract infection are commonly overtreated with antibiotics.

Urinary tract infection (UTI) is one of the most common reasons for oral antibiotic administration in dogs. Researchers in Denmark recently performed a prospective study examining diagnostic methods and treatment choices for UTI in companion animal practice.

Study Design

The authors contacted primary practices in Denmark for voluntary enrollment in the study. All dogs presenting for 1 or more clinical signs consistent with UTI were eligible, but those that had systemic or chronic disease or had been administered antibiotics within 3 weeks before presentation were excluded.

During consultation, in-house diagnostics performed on urine samples included urine dipstick analysis, microscopy, sediment staining, quantitative bacterial culture (QBC), and antibiotic susceptibility testing (AST). QBC and AST were also performed at the University of Copenhagen reference laboratory for a subset of cases. In addition, pet owners recorded clinical signs and treatment administration for 10 days after consultation.


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The investigators examined whether practitioners made the appropriate decision to treat for UTI empirically and after receiving QBC results. They also analyzed whether practitioners selected an appropriate first-line antibiotic for treatment (amoxicillin or potentiated sulfonamides) based on AST results.


Between May 2014 and November 2016, 151 dogs presenting to 52 veterinary practices throughout Denmark were enrolled in the study. Fifty-eight dog breeds were represented, with a mean age of 6 years and mean weight of 21.7 kg. Most dogs were female (73%). The most commonly reported clinical sign was pollakiuria (80%) occurring for a median duration of 3.3 days before consultation.

The most commonly utilized in-house diagnostic procedures were urine dipstick (99%), microscopy (80%), and QBC (56%). Veterinary practitioners tentatively diagnosed UTI in 132 cases (87%) and empirically treated 119 dogs (79%) with antibiotics. Reference lab QBC results subsequently confirmed UTI diagnosis for 77 dogs (51%), including 74 dogs already receiving empiric treatment. Of the 74 dogs negative for UTI, 55 (74%) received empiric antibiotic therapy.

Overall, veterinarians appropriately decided whether to prescribe antibiotics in 62% (93/151) of cases. The use of in-house microscopy, but not QBC, significantly increased the likelihood of appropriately selecting treatment. Compared with reference lab QBC, in-house microscopy and in-house QBC were 65% and 77% accurate, respectively, at detecting UTI.

AST results showed that appropriate first-line antibiotics were selected in 36% of confirmed UTI cases, while second-line agents were prescribed in 57% of cases. Nineteen-percent of bacterial isolates were resistant to 1 or both first-line antibiotics.

Owner diaries were returned for 101 dogs, 53% of which were confirmed positive UTI cases. The median time from consultation to resolution of clinical signs was 2 days for both UTI and non-UTI cases, while clinical signs persisted in 7% of cases 10 days after consultation.


The authors acknowledged that the decision to treat UTI is complex, as delaying treatment until culture and antibiotic susceptibility results are available is not always feasible. Nevertheless, the investigators determined that overtreatment of UTI is a common issue in Danish veterinary practices.

Dr. Stilwell received her DVM from Auburn University, followed by a MS in Fisheries and Aquatic Sciences and a PhD in Veterinary Medical Sciences from the University of Florida. She provides freelance medical writing and aquatic veterinary consulting services through her business, Seastar Communications and Consulting.