The aim of this retrospective study was to document the prevalence of bacterial species in cats with significant bacteriuria and to compare their antimicrobial susceptibilities over five years. One hundred sixty-nine positive urine cultures from 150 cats were included. Fifty-five per cent showed clinical signs, while 40 per cent had subclinical bacteriuria. , species, species, species and accounted for 50.5 per cent, 22.9 per cent, 15,1 per cent, 3.6 per cent and 2.6 per cent, respectively. species was significantly more common in cats with subclinical bacteriuria. species and isolates were resistant to a significantly higher number of antimicrobials than other isolates. Applying the formula to select rational antimicrobial therapy, bacterial isolates were most likely to be susceptible to imipenem, nitrofurantoin, gentamicin and amoxicillin clavulanic acid. Over the study period, only minor differences were noted for the antimicrobial impact factors (IFs) between years and between cats with and without clinical signs. The cumulative IF increased significantly compared with the previous 10 years. Empirical treatment of bacterial cystitis should be avoided whenever possible and, if needed, based on the locally determined bacterial spectrum and antibiotic susceptibility.

Practical relevance: Urinary tract infection (UTI) is an important cause of feline lower urinary tract disease (FLUTD), particularly in female cats older than 10 years of age. In addition to cats with typical clinical signs of FLUTD or upper UTI, many cats have subclinical bacteriuria, but the clinical relevance of this is currently uncertain. UTIs are one of the most important indications for antimicrobial use in veterinary medicine and contribute to the development of antimicrobial resistance. Adherence to treatment guidelines and confinement to a few first-line antimicrobial agents is imperative to avoid further deterioration of the antimicrobial resistance situation. The decision to treat with antimicrobials should be based on the presence of clinical signs, and/or concurrent diseases, and the results of urine culture and susceptibility testing. Clinical challenges: Distinguishing between cats with bacterial cystitis, and those with idiopathic cystitis and concurrent clinical or subclinical bacteriuria, is challenging, as clinical signs and urinalysis results may be identical. Optimal treatment of subclinical bacteriuria requires clarification as there is currently no evidence that demonstrates a beneficial effect of routine treatment. Management of recurrent UTIs remains a challenge as evidence for most alternatives used for prevention in cats is mainly anecdotal, and no preventive treatment modality is currently recommended. Evidence base: This review draws on an extensive literature base in veterinary and human medicine, including the recently updated guidelines of the International Society for Companion Animal Infectious Diseases for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Where published evidence is lacking, the authors describe their own approach; notably, for the bacteriuric cat with chronic kidney disease.

ZusammenfassungBei Harnwegsinfektionen (HWI) handelt es sich um die Anheftung und Multiplikation von Erregern im Harntrakt. Acht bis 19 % der Katzen mit klinischen Symptomen einer Erkrankung der unteren Harnwege leiden an einer HWI. Bei Katzen mit einer subklinischen Bakteriurie kann eine signifikante Anzahl an Bakterien im Urin nachgewiesen werden, obwohl keine entsprechenden Symptome vorliegen. Die Prävalenz der subklinischen Bakteriurie in der Katzenpopulation beträgt 1–29 %. Neben dem am häufigsten isolierten Uropathogen Escherichia coli werden oft Streptokokken, Enterokokken und Staphylokokken nachgewiesen. Harnwegsinfektionen sind ein häufiger Grund für den Einsatz von Antibiotika. Um der zunehmenden Resistenzentstehung vorzubeugen, sollte ein Antibiotikum mit möglichst engem Wirkspektrum basierend auf den Ergebnissen der Kultur und des Antibiogramms gewählt werden. Aktuell ist die Studienlage zur Behandlung der subklinischen Bakteriurie unzureichend. Die meisten Experten empfehlen, nur Patienten mit einem erhöhten Risiko aufsteigender Infektionen antibiotisch zu behandeln.