Bladder cancer in dogs is usually malignant and the most common type is transitional cell carcinoma (TCC). TCC is a cancer that originates in the bladder, kidney or ureters but the most common site for this type of cancer is the bladder. It arises in the transitional epithelium, the membranous tissue covering these organs.

The exact cause of TCC is not totally known but it is suspected that carcinogens that pass out through the urine lead to development of cancer in the lining of these organs. Since the carcinogens tend to be stored in the bladder along with urine, the bladder is the most affected organ.

Some drugs are also known to be metabolized by the liver to produce acrolein, a known human carcinogen. As acrolein is produced in the liver and passed out through the urine, it is also suspected to be one of the causes of urethra and liver cancer in dogs.

Symptoms of bladder cancer in dogs tend to remain hidden for long before diagnosis is done as most of the symptoms resemble those of common urinary infection. If your dog is showing the following symptoms, which refuse to go away even after treatment, further investigative tests should be done to rule out cancer.