Kidney Tumors(Cancer)in Dogs

The kidneys are essential filters that remove toxins and wastes from the blood. Kidneys produce a hormone that stimulates the bone marrow to make red blood cells. They also maintain the correct balance of water, various salts and minerals in the body. Each kidney is connected to the urinary bladder by a ureter, a tube for transport of urine. This complex system can also be affected by cancer in dogs.

There are two types of kidney tumors that exist in dogs; ones that originate from within the kidney and ones that have spread to the kidney from another tumor within the body. Tumors that originate within the kidney include renal carcinoma, renal adenocarcinomas, transitional cell carcinoma, sarcomas of varying types and a tumor that originates from embryonic cells called a nephroblastoma. At the time of diagnosis of a kidney tumor, about 16% of them have evidence of spread of the tumor to the lungs.

Primary kidney tumors are relatively rare dogs and are almost always malignant. About 50% of these tumors arise from the cells that line the kidney tubules (passageways).

Kidney tumors are not often found in dogs, but when they are, they’re usually found in middle-aged and older dogs and require the affected kidney to be removed.

Causes of Kidney Cancer in Dogs

Not much is known about what causes kidney cancer in dogs. The cancer doesn’t prefer a breed or gender, with the exception of German Shepherds, who are predisposed to a syndrome known as renal cystadenocarcinomas.

Symptoms of Kidney Cancer in Dogs

Some dogs do not exhibit symptoms of kidney cancer, though they may begin to show signs as the disease grows. These include:

• Increased thirst
• Frequent urination
• Blood in the urine

If the kidneys begin to fail, the dog may develop additional symptoms such as:

• Loss of appetite
• Vomiting
• Weakness
• Depression
• Dental disease

Diagnosis of Renal Neoplasia in Dogs

• Complete blood count (CBC)
• Biochemical profile
• UrinalysisUrine culture and sensitivity
• Abdominal X-rays
• Chest X-rays
• Abdominal ultrasound
• Intravenous pyelogram
• Abdominal exploratory and biopsy

Treatment

Surgery

Surgical management depends on behaviour of the tumor, presence of metastases and bilateral renal involvement, and invasion of the caudal vena cava and adjacent structures.

Chemotherapy

If the cancer affects both kidneys or has metastasized to other areas of the body, rendering a nephrectomy infeasible, chemotherapy may be used to help combat the spread of the tumors and prolong your dog’s life. Your veterinarian can administer a potent combination of drugs, limiting the cancer’s spread to other organs. However, there is little documentation to support chemotherapy’s effectiveness against most primary renal tumors.