Urinary tract infection and subclinical bacteriuria in cats: A clinical update

Abstract

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.

Hyperthyroidism is not a risk factor for subclinical bacteriuria in cats: A prospective cohort study

“…The results of our prospective study indicate that hyperthyroid cats have a low prevalence (<5%) of subclinical bacteriuria, nearly identical to that found in a cohort of euthyroid cats of similar age and sex presented for routine examination. This finding is in marked contrast to previous retrospective studies that reported a relatively high prevalence of UTI in hyperthyroid cats (12%‐22%), findings that have led to the widespread belief that hyperthyroid cats are at risk for developing subclinical bacteriuria 3,8‐10 . Our findings agree with other recent studies of mixed populations of cats, which failed to identify an increased risk of subclinical bacteriuria in much smaller cohorts of cats with hyperthyroidism 26,27 …”

“…Although hematuria was common, it was not a predictor for subclinical bacteriuria in our study. Because cystitis can lead to the presence RBC in urine sediment, hematuria might be expected in cats with subclinical bacteriuria 3,26 . However, cystocentesis itself can induce transient microscopic hematuria indistinguishable from pathological hematuria, 38,39 and the number of RBCs in the sediment cannot be used as a reliable predictor of a positive urine culture.…”

“…Subclinical bacteriuria (also called occult bacteriuria or asymptomatic bacteriuria) is defined as a positive bacterial urine culture in the absence of clinical evidence of urinary tract infection (UTI) 1 . Studies have recognized subclinical bacteriuria as a common clinical syndrome in humans, cats, and dogs 1‐4 . Retrospective studies of hyperthyroid cats have reported a prevalence of UTI ranging from 12 to 22%, 5,6 and consisting mostly of subclinical bacteriuria.…”

“…Retrospective studies of hyperthyroid cats have reported a prevalence of UTI ranging from 12 to 22%, 5,6 and consisting mostly of subclinical bacteriuria. Consequently, clinicians consider hyperthyroidism a risk factor for development of UTI, 3,7 and many recommend urine culture as a part of the routine evaluation of hyperthyroid cats 8,9 …”

Complications and survival after subcutaneous ureteral bypass device placement in 24 cats: a retrospective study (2016–2019)

“…17 Therefore, urine stasis can predispose to pyelonephritis. 14,[28][29][30][31][32] The incomplete pigtail formation was also observed by others in a very recent study; despite intraoperative fluoroscopy, penetration of the kidney with subcapsular leakage was noted postoperatively. In the same study, an incomplete deployed pigtail led to obstruction of the nephrostomy catheter in one cat, leading to euthanasia.…”