Signs and symptoms of bladder cancer in dogs aren't subtle, as the majority involve obvious urinary issues. While you can't prevent your dog from developing bladder cancer, you can reduce the risk by keeping him in a smoke-free home and limiting his exposure to pesticides. While it's not the most pleasant part of pet ownership, it's good animal husbandry to pay attention to your dog's elimination habits, so you're aware of any changes.
Although various types of bladder cancers affect canines, the most common is transitional cell carcinoma. This type of tumor metastasizes -- or spreads -- quickly, which means early diagnosis and treatment is imperative for your dog's long-term survival. Usually, transitional cell carcinomas spread throughout the lymphatic system and into the lungs. The tumor, which might be single or form numerous projections in the bladder layers, interrupts the normal flow of urine.
While any dog can develop bladder cancer, some breeds are more susceptible than others. Female dogs have higher rates of bladder cancer than males. Some affected breeds -- beagles, West Highland white terriers, Scottish terriers, wire-haired fox terriers, Airedales and Shetland sheepdogs -- appear to have a genetic predisposition to bladder cancer, according to the Veterinary Cancer Center in Norwalk, Connecticut. Overweight dogs have a higher incidence of bladder cancer than normal-sized canines.
Bladder cancer symptoms include difficulty urinating, blood in the urine and frequent urination. Don't panic if your dog develops any of these symptoms, as they're also common in urinary tract infections. Nonurinary tract signs include weight loss. You might feel a mass in your dog's abdomen, and your pet might exhibit signs of abdominal pain. Less often, dogs suffering from a bladder tumor might experience difficulty walking and obvious lameness. If your dog displays such symptoms, get him to the vet for an examination as soon as possible.
Your vet diagnoses bladder cancer initially through a physical exam, feeling for a thickened urinary bladder wall via a rectal palpation. She'll also conduct a complete blood count and urinalysis and take X-rays or perform an abdominal ultrasound to detect tumors. If your dog is female, your vet can use a cytoscope -- a tiny camera threaded into the bladder -- to view the tumor or collect a sample for biopsy. Treatment depends on tumor stage, with small tumors least likely to have spread making them the best surgical candidates. Other treatments include chemotherapy, laser therapy and radiation.
The prognosis for many dogs diagnosed with bladder cancer isn't good. Without treatment, a dog generally will succumb within a few months, but treatment with the nonsteroidal anti-inflammatory piroxicam can relieve pain and symptoms for up to nine months. Chemotherapy might add another several months, as can laser therapy.