Bacteria represent the most common cause of urinary tract infection. Antimicrobial drugs are the cornerstone of treatment of urinary bacterial infections. Because of the chronic nature of urinary bacterial infections urinary tract infection (UTI) and the potential for antibiotic resistance, a natural approach to prevention and treatment is desirable. This study evaluated the efficacy of a polyphenolic extract obtained from cranberries. The product was daily orally administered to 10 dogs with bacterial cystitis for a period of 60 days. The results obtained, despite of the small population under study, suggest a potential efficacy of the product in treating bacterial cystitis.