Antimicrobial susceptibility in bacterial isolates from Norwegian cats with lower urinary tract disease.

Studies of feline lower urinary tract disease (FLUTD) among Norwegian cats have shown higher prevalences of bacterial cystitis than most previously published reports. The aims of the present study were to identify bacterial isolates obtained from the urine of Norwegian cats with FLUTD and their susceptibility to antimicrobial agents. Eighty-two bacterial isolates from 72 urine cultures obtained from 71 different cats were included. Escherichia coli, Staphylococcus species, Enterococcus species and Streptococcus species were the most frequently detected. The percentages of isolates susceptible to the included antimicrobial agents were as follows: enrofloxacin - 92%; trimethoprim/sulfonamide - 91%; nitrofurantoin - 89%; tetracycline - 78%; ampicillin - 73%; amoxicillin/clavulanic acid - 72%; trimethoprim - 68%; amoxicillin - 58%; cephalexin - 51%; spiramycin - 39%; penicillin - 34%; fucidic acid - 34%; lincomycin - 27%. Although several tendencies towards increasing antimicrobial resistance were detected among the isolates included, the species of bacteria isolated and their patterns of antimicrobial resistance were, in general, in concurrence with the existing literature. Thus, the results do not fully explain the higher prevalence of bacterial cystitis found in Norwegian cats. Moreover, additional explanatory factors beside the inclusion of primary accession cases rather than referred cases were not found.