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

## TL;DR

Urinary bladder cancer in dogs and cats is aggressive and hard to detect early, with risk factors like age, breed, and environmental exposures needing more study to improve diagnosis and prevention.

## Contribution

This narrative review synthesizes current knowledge on risk factors for urinary bladder cancer in dogs and cats, emphasizing the need for clearer understanding to improve early detection and prevention.

## Key findings

- Urinary bladder cancer in dogs and cats is influenced by factors like breed, sex, age, obesity, and environmental exposures.
- In dogs, female Terriers are more susceptible, while in cats, males and short-haired breeds are more commonly affected.
- Dietary patterns, such as vegetable consumption, may reduce cancer risk in dogs.

## Abstract

Urinary bladder cancer is a highly aggressive disease in pets, yet its risk factors remain poorly explored. Early diagnosis is difficult because clinical signs often resemble those of common urinary tract infections. Current evidence highlights several potential contributors, including age, sex, neutering status, obesity, breed-related genetic predisposition, environmental exposures, tobacco smoke, certain flea control products, and diet. These factors may act independently or interact to increase susceptibility. A clearer understanding of these risks is essential to improve disease recognition, support earlier diagnosis, and reduce animals’ exposure to preventable predisposing 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.