Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Diagnostic tests are needed to identify urinary bladder cancer, exclude other diseases and determine the impact of bladder cancer on your pet. Tests may include: Complete medical history and thorough physical examination including rectal examination to evaluate the urethra, bladder neck, prostate gland in males and local lymph nodes.
Abdominal and chest X-rays to evaluate for abnormalities of the bladder, enlargement of local lymph nodes and spread of cancer to the lungs. It is not unusual for bladder cancer to spread to the local lymph nodes in the abdomen.
Complete blood cell count (CBC) to evaluate red cells, white cells, and platelets, which are responsible for normal blood clotting. The CBC is a standard screening test to assess your pet's general heath and insure that it is safe to perform other procedures, such as surgery, on your pet. The presence of anemia may suggest longstanding or severe blood loss or a chronic disease process.
Serum biochemistry tests to evaluate your pet's general health, assess the function of other organs such as the liver and kidneys and identify electrolyte and acid base disturbances.
Urinalysis to evaluate for the presence of white cells, red cells, bacteria and crystals. Occasionally, bladder tumor cells can be identified by microscopic examination of the urine. Kidney function can be evaluated by a test of urine concentration called "specific gravity."
Abdominal ultrasound to evaluate for tumors in the bladder and urethra, stones in the urinary tract, or urinary tract obstruction. Ultrasound examination allows internal structures to be evaluated on a monitor as ultrasonic waves are transmitted to and reflected from tissues. Ultrasound is a specialized procedure that may require referral to a veterinary specialist. It is not painful to your pet and is tolerated well by most dogs. It does require that some of the pet's hair be shaved from the abdomen.
Special contrast X-ray studies to evaluate for bladder tumors, stones, or urinary tract obstruction. Radiographic dye is called "positive" contrast because it appears white on the X-ray, and air is called "negative" contrast because it appears black on the X-ray. Either can be introduced into the bladder via the urethra to evaluate for bladder tumors. Such a study is called a urethrocystogram.
Cystoscopy to evaluate the urethra and bladder for stones, tumors or congenital defects. Cystoscopy is a specialized test in which a flexible or rigid scope is passed into the urethra and bladder for direct visualization while the pet is under general anesthesia. This test typically requires referral to a veterinary specialist. It allows bladder tumors to be identified by their characteristic "frond-like" appearance and allows biopsy samples to be taken for pathologic analysis.
The V-TBA, or urinary tumor bladder antigen, test has been developed recently to allow identification of tumor markers in urine.
Treatment of bladder cancer rarely is curative and more often is used with the intention of controlling the disease temporarily, relieving partial urinary tract obstruction, and making the pet more comfortable for a variable period of time. Such an approach will usually improve your pet's quality of life and allow you to spend more time with your pet. Unfortunately, bladder cancer usually is very advanced in dogs by the time it is diagnosed. Often, it already has metastasized to local lymph nodes in the abdomen. Surgery. Small masses confined to the fundus or body of the bladder can be removed surgically. Despite this, the cancer can appear in other areas of the bladder. Also, bladder tumors that affect the region of the bladder into which the ureters empty (called the trigone), the bladder neck, and first portion of the urethra are not accessible for surgery. For these reasons, surgery often is not recommended for many pets with bladder cancer. Surgery, however, can serve as a diagnostic tool to obtain biopsy specimens of bladder masses or, in advanced cases, to place a tube in the bladder that comes out the through the abdominal wall allowing the owner to drain the animal's bladder manually several times a day as needed. This is a cystostomy tube.
Treatment for bladder cancer may include one or more of the following:
Cancer chemotherapy. Treatment protocols using anti-cancer drugs can be used to manage pets with bladder cancer. These drugs are often very toxic, resulting in adverse effects such as bone marrow suppression leading to low white cell count, gastrointestinal toxicity with nausea and vomiting, and kidney toxicity. A specialist in veterinary oncology should be consulted about chemotherapy for bladder cancer. Examples of some anti-cancer drugs used in dogs with bladder cancer include cisplatin, carboplatin, and mitoxantrone. Remissions of six months and sometimes longer have been achieved with chemotherapy.
Piroxicam (Feldene®) is a non-steroidal anti-inflammatory drug that has been used to treat pets with bladder cancer. Its mechanism of action is not well understood but partial remission occurs in 25 percent of treated dogs, stabilization of disease occurs in 50 percent and, unfortunately, progression of disease occurs in 25 percent of treated dogs. The main toxicity of piroxicam is gastrointestinal upset.
Radiation therapy can be used to treat some bladder cancers by directing a beam of radiation at the affected area and sites of metastasis. Radiation therapy is a highly specialized form of treatment available only at selected referral centers and teaching institutions. Radiation therapy is associated with adverse effects because overlying skin and surrounding tissues also can be damaged by the radiation. A veterinary oncologist should be consulted about the advisability of radiation therapy for your pet's bladder cancer.
Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be crucial. Administer any prescribed medications as directed by your veterinarian and contact your veterinarian if you experience difficulty treating your pet.
Activity should be restricted in the postoperative period while your pet is recovering from surgery to obtain a biopsy, remove a tumor, or place a cystostomy tube to allow proper healing of the surgery site. Your pet may need to have sutures removed from the skin 10 to 14 days after surgery.
Results of the biopsy report will help your veterinarian decide the optimal treatment approach for your pet.
If you consult a veterinary oncologist and begin chemotherapy for your pet, you will need to watch for signs of toxicity and to evaluate your pet's ability to urinate more normally. A schedule of follow-up visits will be designed to evaluate your pet's response to treatment using tests such as ultrasound examination, contrast X-ray studies and occasionally cystoscopy.
Signs to watch for that may indicate that cancer has progressed or spread include: straining to urinate or defecate, decreased activity, shortness of breath, coughing, and decreased appetite. Signs such as loss of appetite, fever, vomiting or diarrhea also may indicate toxicity associated with chemotherapy. Contact your veterinarian or veterinary oncology specialist if you observe any of these signs.
Prevention Avoid dipping your pet with insecticides used to control fleas and ticks more than two times per year due to a statistical association of such products with increased risk of bladder cancer. If you live in an area of the country where fleas and ticks are a year-round problem, talk to your veterinarian about alternative forms of flea and tick control.
Proper diet and regular exercise are important for your pet, and a statistical association of obesity and bladder cancer in dogs has been identified.
Breeds such as the Shetland sheepdogs, Scottish terriers and West Highland white terriers have increased risk for bladder cancer and should be observed carefully as they age for potential signs of bladder cancer, such as blood in the urine, straining to urinate and increased frequency of urination.
Exposure to the drug cyclophosphamide used to treat cancer and some immune-mediated diseases and its carcinogenic breakdown product (acrolein) has been incriminated in development of bladder cancer. Pets that have been treated with this drug should be monitored for potential signs of bladder cancer like blood in the urine, straining to urinate and increased frequency of urination.