Urinary tract infections (UTIs) are highly prevalent in companion animals. According to studies, UTIs are significantly common in dogs (44.6%), and cats (18.6%), with higher frequency in females (30.1%). 

Common Causes

• E. coli: Escherichia coli is the predominant pathogen in both species.
• Other Pathogens: Following E. coli, Proteus spp. and Staphylococcus spp. are common in dogs, while Staphylococcus spp. is more common in cats.
• Antimicrobial resistance (AMR) in pet urinary tract infections (UTIs), driven by overuse of antibiotics, with up to 37–75% of isolates showing multi-drug resistance (MDR) in studies.

Symptoms

• Inability to urinate or only passing a small amount of urine.
• Increased amount and/or frequency of urination.
• Apparent loss of bladder control.
• Bloody or cloudy urine.
• Constant licking of urinary opening.
• Strong odor to the urine.
• Signs of Lethargy or decreasing health.
• Changes in appetite
• Weight loss
• Vomiting
• In cats - abdomen seems bloated or hard to the touch.
• Increased water consumption.

Treatment

First line of defense as prescribed by veterinarians will typically be antibiotics. Amoxicillin or Trimethoprim-sulfonamide (TMS) are typically used for 3 to 5 days. These are usually very effective. But if UTI’s are recurring, the best approach is to get ahead of them by taking preventive measures. Without doing so there is a risk of your pet getting resistant to antibiotics, resulting in them becoming ineffective. Here are some preventive steps that can be taken:

• Hydration: Constant access to fresh water is crucial to dilute urine and flush bacteria from the urinary tract.
• Nutrition: Feeding diets that manage urinary pH and are lower in magnesium and phosphorus helps prevent the formation of stones/crystals.
• Hygiene & Grooming: Regular grooming around the perineal area reduces the risk of bacteria entering the urethra.
• Providing Frequent/Regular Urination Opportunities: Regular opportunities for urination prevent urine stagnation, allowing innate immunity to clear bacteria.

Therapeutic Supplements for Prevention

Cranberry Extract

• Mechanism of Action: Cranberry extracts contain A-type proanthocyanidins (PACs), which disrupt the ability of P-fimbriated Escherichia coli () to adhere to the epithelial cells lining the urinary tract.
• Efficacy (Dogs):  Research shows that oral administration of cranberry extract can prevent UTI recurrence in dogs by significantly reducing bacterial adhesion. A study with 12 dogs showed no UTIs over 6 months.
• Efficacy (Cats): Preliminary data suggests cranberry, may assist in reducing clinical signs of feline idiopathic cystitis.

D-Mannose

• Mechanism of Action: E.coli has mannose-receptors that bind to D-Mannose, stopping the bacteria from colonizing the bladder lining.
• Efficacy: Research indicates it is effective for recurrent UTIs in dogs and cats. It is frequently utilized in conjunction with other treatments for urinary health.
• Immunomodulatory Effects: A recent study suggests D-mannose can improve gut microbiota and increase serum IgG levels (immune function) in cats.

Probiotics

• Mechanism of Action Probiotics compete with harmful uropathogens for adhesion sites and nutrients on the epithelial surfaces of the gut and potentially the urogenital tract, preventing pathogenic colonization.
• Efficacy: Can improve gut health, potentially reducing the fecal bacteria that commonly cause UTI infection.
• Natural Antibiotic: Promising studies show that specific probiotics can fight UTI pathogens, can act as a natural alternative to antibiotics in dogs

Cranberry, D-mannose, and probiotics have been shown to be effective preventive nutrition, helping  to preemptively  to stop UTI’s before they happen, and keep your pet away from having to be caught in a loop of infection and antibiotic use.

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References

Thassakorn P, Sukon P, Phuektes P, Fungbun N. Prevalence of Bacterial Urinary Tract Infections in Dogs and Cats with Lower Urinary Tract Diseases and Other Illnesses: A Systematic Review and Meta-Analysis. Animals (Basel). 2025 Nov 30;15(23):3456. doi: 10.3390/ani15233456. PMID: 41375516; PMCID: PMC12691362.

Prevalence and Antimicrobial Resistance of Bacterial Uropathogens Isolated from Dogs and Cats Sophie Aurich^*, Ellen Prenger-Berninghoff and Christa Ewers Institute of Hygiene and Infectious Diseases of Animals, Faculty of Veterinary Medicine, Justus Liebig University Giessen, D-35392 Giessen, Germany Antibiotics 2022, 11(12), 1730;https://doi.org/10.3390/antibiotics11121730

Effects of cranberry extract on prevention of urinary tract infection in dogs and on adhesion of Escherichia coli to Madin-Darby canine kidney cells Hsin-I Chou DVM, MS Kuan-Sheng Chen DVM, PhD Hsien-Chi Wan DVM, PhD, and Wei-Ming Lee DVM, PhD

Hutchins RG, Bailey CS, Jacob ME, Harris TL, Wood MW, Saker KE, Vaden SL. The effect of an oral probiotic containing lactobacillus, bifidobacterium, and bacillus species on the vaginal microbiota of spayed female dogs. J Vet Intern Med. 2013 Nov-Dec;27(6):1368-71. doi: 10.1111/jvim.12174. Epub 2013 Aug 28. PMID: 24033665.

Ala-Jaakkola R, Laitila A, Ouwehand AC, Lehtoranta L. Role of D-mannose in urinary tract infections - a narrative review. Nutr J. 2022 Mar 22;21(1):18. doi: 10.1186/s12937-022-00769-x. PMID: 35313893; PMCID: PMC8939087.