Prevalence and Antimicrobial Resistance Trends of Canine Uropathogens in a Veterinary Teaching Hospital in Northern Italy: A 10-Year Retrospective Study (2014–2023)

Urinary tract infections (UTIs) are a major driver of antimicrobial use in canine veterinary practice. The International Society for Companion Animal Infectious Diseases (ISCAID) guidelines recommend that empirical antimicrobial therapy be guided by locally updated data on pathogen prevalence and resistance patterns. This retrospective study analyzed 201 positive urine cultures obtained via cystocentesis from dogs at a veterinary teaching hospital in northern Italy between 2014 and 2023. The aim was to assess uropathogen distribution and antimicrobial resistance trends before and after the 2019 ISCAID guideline release. Escherichia coli was the predominant isolate (47.5%) showing stable prevalence over time. High resistance rates were observed for amoxicillin (62.4%), whereas resistance to trimethoprim–sulfamethoxazole was lower (33.6%). Importantly, resistance to amoxicillin–clavulanate declined significantly from 52.6% to 25.6% (p = 0.0002). These findings suggest amoxicillin alone may be suboptimal for empirical therapy locally, while amoxicillin–clavulanate and trimethoprim–sulfamethoxazole remain suitable first-line agents. Ongoing local surveillance is essential to support evidence-based antimicrobial stewardship.