Urinary Bladder Cancer in Cats

Urinary bladder cancer in cats is characterized by an abnormal growth of cells within the urinary bladder. The most common type of urinary bladder cancer seen in cats is called transitional cell carcinoma (TCC). This type of cancer forms from the cells lining the thick wall of the bladder and can quickly spread to the lymph nodes, kidneys, lungs, and bones as well as adjacent urinary tract organs (vagina, prostate, urethra, ureters). Urinary bladder cancer is a rare disease in cats but this type of cancer is fast acting and deadly. 

Like most forms of cancer, urinary bladder cancer in cats is an abnormal growth of cells that has occurred for idiopathic (unknown) reasons. Urinary bladder cancer is most commonly seen in female cats around the age of seven, but is also seen in males. Urinary bladder cancer in cats mimics the same symptoms as a bladder infection or bladder stones, which makes it critical for pet owners to have their feline examined by a veterinary medical professional. 

The first signs of urinary bladder cancer mimic those of a bladder infection and most pet owners interpret straining to urinate, frequent urination, and urinary incontinence as a simple bacterial infection. Urinary bladder cancer, however, easily spreads to other areas of the body and may soon show the following symptoms:

• Bloody urine
• Urethral obstruction causing an inability to urinate
• Pain upon palpation of the back or pelvic regions
• Weakness
• Exercise intolerance
• Polydipsia
• Polyuria with only a small amount of urine passed
• Vocalization upon urination 
• Coughing 
• Difficulty breathing
• Vomiting
• Anorexia
• Weight loss
• Abdominal swelling

If the feline has an obstructed urethra, the cat will have a full bladder without the ability to urinate, which becomes an emergency situation instantly. If your cat is continuously going to the litter box to urinate and no urine has been passed, seek emergency veterinary help immediately. 

Urinary bladder cancer in cats, as well as in all other mammals, occurs for idiopathic reasons. Cancer itself is the result of mutated cells upsetting the body’s routine regulation of cell replacement, but the particular reason why this happens is not straightforward. Genetics likely play a role. Veterinary specialists have reported that obese felines have a higher chance in developing the disease, but excessive weight is not directly linked to this condition. 

Diagnosing urinary bladder cancer in cats begins with a physical examination, blood tests and urinalysis. A urinalysis can assess for crystals and bacteria and may also detect the signs of urinary cancer, as traces of cancer cells can occasionally be found in the urine. A feline’s blood work often has a normal result even if he or she does have urinary cancer, but a blood analysis is helpful to evaluate other organs the cancer may be affecting. Your veterinarian may choose to perform a VBTA test, or veterinary bladder tumor antigen test, a type of urine screening test to detect a bladder tumor. The VBTA test will either show a positive or negative result. If the result is positive, your veterinarian may proceed to perform the following diagnostic exams: 

Ultrasound

An ultrasound of the abdomen can help the veterinarian determine the size, location and activity of any tumor inside the bladder.

X-ray

An x-ray may be used to detect where the cancer has spread throughout the body, but may prove ineffective for locating the bladder tumor itself without a highlighting element (cystogram).

Cystogram

A cystogram is a test that introduces a special dye that will highlight the insides of the cat and highlight the tumor on x-ray. 

Biopsy

Once the tumor is located, a biopsy can be taken from the mass to evaluate if it is malignant or benign.  

Treating urinary bladder cancer in cats can be attempted through surgical removal of the tumor, chemotherapy and/or radiation therapy. 

Surgical Treatment

Surgically removing the bladder tumor is only possible when the mass is located in a non-invasive area. If the tumor is found within the urethra or ureters, as in most cases, surgical removal would not be advised for these are vital structures. In that case, the veterinarian may perform a debulking surgery which would simply reduce the tumor in size. Debulking is only a temporary treatment to alleviate symptoms, as the mass will continue to grow back. 

Chemotherapy Treatment

The perfect chemotherapy drug mixture is still to be decided for effectively treating urinary bladder cancer, as less than 20 percent of felines respond to the current protocol. 

Radiation Therapy Treatment

Radiation therapy has proven to be more effective than chemotherapy in treating urinary bladder cancer in cats, but radiation rays often damage urinary structures.  

Treatments for urinary bladder cancer in cats are performed to give a feline a better quality of life, but there is no cure for this disease. 

Whether you choose to seek treatment for your cat’s urinary bladder cancer or not, the overall prognosis for an affected cat is poor. Cats that have received treatment are estimated to live between six months to a year, whereas untreated cats often pass at four to six months. 

Your veterinarian may prescribe an anti-inflammatory drug, such as pirioxicam, to relieve bladder pain and provide a better quality of life for your cat. Ask your veterinarian about the best recovery and management options for your cat, as each urinary bladder cancer case is different.