Objective: To investigate the prevalence of comorbidities (CM) in cats with urinary tract infections (UTIs), as well as the prevalence of bacterial species in cats with different CM and their antimicrobial susceptibility to the commonly used antibacterial agents doxycycline, trimethoprim-sulfamethoxazole (TMS), amoxicillin-clavulanic acid (AMC), cephalothin, and enrofloxacin.
Material and methods: A retrospective analysis of cats with positive urine cultures in the years 2003 to 2009 was performed. Cats were assigned to one of four groups: cats with systemic comorbidities (sCM), cats with indwelling urinary catheters (iUC), cats with local comorbidities (lCM), or cats without CM. To evaluate the potential effectivity of the antibiotics the antibacterial impact factors were calculated.
Results: A total of 194 cats with 219 isolates were included in the study. In 78.4% (152/194) of cats, a CM was identified; 49.5% had a sCM and 28.9% (56/194) had an iUC or a lCM. Cats with sCM were significantly older than cats in all other groups, and the proportion of female animals was higher in cats with sCM than in cats with iUC or lCM. More than half of the cats with sCM did not show clinical signs of lower urinary tract disease. The most commonly isolated bacteria species were Escherichia (E.) coli, Streptococcus spp., Staphylococcus spp., and Enterococcus spp. with a significantly higher proportion of E. coli isolates in cats with sCM and significantly higher proportions of Streptococcus and Staphylococcus spp. isolates in cats with iUC and other lCM. According to the antimicrobial impact factors bacterial isolates in cats with any CM were most likely susceptible to AMC and TMS. Isolates from cats with iUC and lCM had a lower likelihood to be susceptible to the tested antimicrobials than cats with sCM and cats without CM.
Conclusion and clinical relevance: Relevant comorbidities for bacterial urinary tract infection were identified in the majority of cats in the present study. Cats with sCM often do not show clinical signs of lower urinary tract disease. AMC and TMS were the antimicrobial agents with the highest antimicrobial impact factor in this population of cats.
Keywords: Urine; antibiotics; bacterial cystitis; feline; systemic disease.