Silent Threats: A Narrative Review of Urinary Bladder Cancer in Dogs and Cats—Epidemiology and Risk Factors

Urinary bladder neoplasms are clinically relevant in dogs and cats and are also common in humans, all of which may share exposure to environmental factors that influence disease risk. In Veterinary Medicine, however, their etiological determinants remain poorly defined. Urinary bladder neoplasia range from non-invasive lesions limited to the mucosa to invasive forms that infiltrate the muscular layer, which are more aggressive and metastatic. In dogs, invasive urothelial carcinoma (UC) represents the most frequently diagnosed type, while in cats, it is less common but displays similar biological behavior. Hematuria and dysuria are the predominant clinical signs, and although urinary bladder cancer accounts for only a small proportion of canine neoplasms, it is associated with considerable morbidity and mortality. Several risk factors have been identified, including breed, sex, age, obesity, diet, neuter status, and environmental exposures. Female dogs, especially Terrier breeds, are more susceptible, whereas in cats, males and short-haired animals are more often affected. Contact with insecticides, herbicides, and antiparasitic products is a recognized risk factor in dogs, although this association has not been consistently demonstrated in cats. Neutering and obesity appear to increase risk in dogs, and dietary patterns may offer protection, with regular vegetable consumption linked to a reduced incidence. Understanding these determinants is essential to improve early detection, guide preventive measures, and strengthen comparative oncology research.