Constructing a Perspective of Probiotic Bacteria in the Management of Urinary Tract Infection in Cats: A Scoping Review.

Feline lower urinary tract disease (FLUTD) and urinary tract infections (UTIs) pose a significant clinical challenge in companion animal medicine. Increasing antimicrobial resistance and emerging insights into the feline urinary microbiome highlight the potential of probiotic-based therapeutic strategies. However, the scope and quality of existing evidence in feline medicine remain unclear. This study aimed to systematically map and characterize the literature on probiotic microorganisms (particularly Lactobacillus spp. and Bifidobacterium spp.) in feline urinary health, identifying research domains, evidence gaps, and future priorities. A scoping review identified peer-reviewed studies addressing FLUTD, urinary microbiota, antimicrobial resistance, and probiotic interventions. Studies were categorized into four domains: clinical burden, microbiome evidence, clinical probiotic evidence, and mechanistic probiotic evidence. Fifty-three studies met inclusion criteria. The main finding of this review is that there is limited to no direct evidence on the use of probiotics for the management of FLUTD or UTIs in cats: only nine studies addressed probiotics (clinical probiotic evidence: n = 5; mechanistic probiotic evidence: n = 4), and no randomized controlled trials specifically assessing probiotic efficacy in cats were identify. Most literature focused on clinical burden (n = 37), comprising epidemiological surveys and antimicrobial resistance reports, whereas microbiome investigations were limited (n = 7). The high prevalence of Escherichia coli and increasing antimicrobial resistance underscore the need for alternative strategies. Addressing this gap through well-designed clinical trials in cats is essential before probiotic-based strategies can be recommended to improve both clinical outcomes and animal welfare in feline patients.