The soft tissue cancers known as rhabdomyosarcomas occur primarily in the oral cavity and its related regions, as well as in the urinary tract. The botryoid type of these malignancies are tumors with a grapelike clustered appearance. Botryoid rhabdomyosarcomas most often appear in the bladder.
While other forms of canine bladder cancer usually affects older dogs, botryoid rhabdomyosarcomas generally afflict dogs under the age of 2. Large breeds, such as the Saint Bernard, are most vulnerable to these relatively rare tumors, and females are more likely to develop the cancer than males. These tumors are primarily located on a smooth section of the bladder known as the trigone, but they can grow on the bladder wall. They can also extend into the urethra, obstructing urinary flow.
In its early stages, botryoid rhabdomyosarcoma might be mistaken for a bladder infection. An affected dog might have difficulty urinating, with blood appearing in his pee. Rather than relieve himself in a steady stream, he might pee in small amounts in different locations. Your veterinarian might initially treat him for a bladder infection -- but that malady generally clears up promptly with antibiotics. When the antibiotic therapy fails to do the trick, more extensive testing is necessary.
Your veterinarian will conduct blood tests and a urinalysis on your dog, along with X-rays and a computed tomography scan for diagnosis. After the tumor is identified, you vet will conduct a biopsy. Once botryoid rhabdomyosarcoma takes hold, it becomes extremely invasive. Your veterinarian can perform surgery to remove the tumor, but it's hard for a surgeon to eradicate the entire tumor, and the operation might not prove successful. After surgery, your dog will likely undergo chemotherapy to stabilize or prevent further tumor growth. Your vet will probably prescribe nonsteroidal anti-inflammatories for pain management.
Botryoid rhabdomyosarcoma usually metastasizes to the bones or the dog's internal organs via the lymph nodes. Unfortunately, if the cancer metastasizes, most dogs don't live more than a year, even after receiving surgery and chemotherapy. With surgery alone, many dogs don't live more than a few months. The dire prognosis is something to consider if expenses are tight, as surgery and chemotherapy are costly. If these treatments aren't an option for you, speak to your veterinarian about palliative treatment that can keep your dog comfortable until you make a decision regarding euthanasia.
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