Bladder Cancer in Dogs

Many times bladder cancer is misdiagnosed as a urinary tract infection or kidney infection. Your veterinarian may need to do more diagnostic testing to properly diagnose bladder cancer in your dog. 

Bladder cancer, especially transitional cell carcinoma is more common in older female dogs. Shetland Sheepdogs, Scottish Terriers and West Highland White Terriers are at a higher risk of developing bladder cancer. Research has shown that Scottish Terriers that have been exposed to certain herbicides were at a higher risk of developing bladder cancer than those dogs not exposed to the herbicides.

Bladder cancer in dogs is not very common, but when it does occur it is most often transitional cell carcinoma or TCC. There are many different types of bladder cancers. Some cancers begin in the bladder and other cancers have metastasized and moved into the bladder from other parts of the body. Most bladder cancer diagnoses come when the cancer is already in advanced stages and treatments are many times unsuccessful.

Dogs that are suffering from bladder cancer will be in pain and will exhibit signs of having difficulty urinating. Depending on the stage of the cancer, a blockage may have formed in the bladder causing all functions of the bladder to cease. If you see your dog struggling with urinating or any of these other symptoms, contact your veterinarian immediately for an appointment. 

• Blood in the urine
• Straining to urinate
• Urinating often
• Painful urination
• Lameness
• Lethargy
• Vomiting
• Refusing to eat or drink

Since bladder cancer in dogs is rare, there has not been enough research conducted to conclusively report the cause of bladder cancer. Researchers do know that there are three dog breeds that seem to be more susceptible to developing bladder cancer: the Scottish Terrier, West Highland White Terrier and Shetland Sheepdog. 

Researchers also know that in the Scottish Terrier, those exposed to certain herbicides were at a higher risk of developing bladder cancer. This research concludes that certain herbicides can cause bladder cancer in dogs. 

Other research suggests that genetics also play a role in the development of bladder cancer. This suggests that there is a specific gene that is passed from parent to offspring that predisposes them to bladder cancer.

Diagnosing bladder cancer can be difficult since the symptoms are almost exactly the same as bladder stones or a urinary tract infection. Your veterinarian will begin by taking a full medical history and then performing a physical examination. Your dog’s abdomen will be palpated as well as a rectal examination. This will help your veterinarian to determine if there is a mass in the bladder, either a tumor or stones. 

Your veterinarian will order x-rays and an ultrasound of the bladder. A biopsy of the tumor will be performed to definitively diagnose bladder cancer. A complete blood count, biochemistry panel and urinalysis will also be performed. An ultrasound of the chest may also be performed to see if the cancer has spread.

Usually, by the time bladder cancer is diagnosed, the cancer has metastasized and treatments will not be effective. Many times, because of the location of the tumor in the bladder, it is virtually impossible to surgically remove them. There have been some cases where the entire bladder has had to be removed.

Radiation therapy may be used to try and shrink tumors within the bladder. Radiation therapy does have many adverse effects including inflammation of the bladder, incontinence and difficulty urinating.

Chemotherapy may also be used. Your veterinarian will probably administer cisplatin with piroxicam. This combination of chemotherapy medications has had a good percentage of dogs going into remission. However, chemotherapy may cause renal toxicity. 

Supportive care will also be necessary for your dog while they are undergoing treatments for bladder cancer. Your dog will be at a higher risk of developing secondary bacterial infections. Urine cultures should be regularly performed to ensure that your dog has not developed a bacterial infection. Catheterization may be required if your dog is unable to freely pass urine out of their bladder. Antibiotics and anti-inflammatory medications may also be needed.

Your dog’s prognosis is poor. Your veterinarian will speak with you regarding your dog’s diagnosis, treatment and overall prognosis. In cases where the bladder cancer has already metastasized and your dog is in extreme pain, euthanasia will be recommended. 

Early detection of bladder cancer will give your dog a better prognosis. If your dog is a breed that is predisposed to bladder cancer, have them screened regularly. You can take steps to prevent your dog from developing bladder cancer such as limiting their exposure to chemicals, especially herbicides.