Bladder Cancer in Dogs

Bladder cancer is the most tumor of the urinary tract and comprises about 1% of all cancers in dogs and cats. Dogs develop this type of tumor more often than cats. Risk factors include nitrosamines, insecticide dips, cyclophosphamide, Sentinil, obesity, and living in an industrial location.

The most common type of urinary bladder cancer is transitional cell carcinoma (TCC). This is a tumor of the cells that line the inside of the urinary bladder. Other less common types of tumors of the bladder may include leiomyosarcomas, fibrosarcomas and other soft tissue tumors. TCC can also appear in the kidney, ureters, urethra, prostate or vagina. It can spread (metastasize) to the lungs, lymph nodes, bones or other organs.

While any breed of dog can develop bladder cancer, a genetic predisposition may be a risk factor since the disease is seen in Scottish Terriers far more than any other breed of dog. Beagles, Shetland sheepdogs, West Highland terriers, and wire hair fox terriers also appear to face an increased risk of developing bladder cancer. Bladder cancer is most often diagnosed in middle-aged and senior female dogs of the breeds listed.

Causes of Bladder Cancer in Dogs

Bladder Cancer in Dogs is quite rare, with only one-percent of canines being diagnosed with this type of cancer. There is still much research being conducted on rhabdomyosarcoma in canines. This soft-tissue cancer can be caused by:

• Genetics
• Wastewater parasites
• Trauma to the muscle
• Foreign bodies
• Orthopedic implants

Signs and Symptoms of Bladder Cancer in Dogs

Bladder cancer is tricky to diagnose and can mimic signs of other lower urinary tract diseases, like urinary tract stones and infections.

The most common symptoms of bladder cancer in dogs are:

• urinating small amounts frequently
• difficulty urinating
• bloody or discolored urine
• accidents in the house

Some dogs may also develop persistent urinary tract infections that do not resolve with treatment. It is important to remember, too, that any changes in urination habits, especially bloody urine or difficulty urinating, require a call to your veterinarian’s office.

Diagnosis

Tumor staging is performed to determine the best way to treat the cancer, to provide some information regarding prognosis, and to establish a baseline tumor measurement in order to determine if treatment is successful. Tumor staging for TCC includes radiographs of the thorax to look for lung metastasis, radiographs and ultrasound of the abdomen to look for metastasis in the abdomen and to assess any changes in the kidneys that result from obstructed urine flow. This information is needed to best plan how to treat the cancer.

Treatment Options For Bladder Cancer in Dogs

The goal of treatment is to slow cancer progression and improve your pet’s quality of life as much as possible. Available treatments include:

• Piroxicam, an oral NSAID that decreases inflammation around tumors and helps to improve or resolve clinical signs. It has been found to have slowed tumor growth in approximately 18% of pets.
• Chemotherapy, which can be used together with Piroxicam to treat TCC. Chemotherapy does not cause the same dramatic side effects in pets as it does in humans.
• Radiation therapy is also a possible option and can be performed while your pet is under anesthesia.