Kidney Cancer in Cats

Older cats are more susceptible to developing cancers of the kidney. The older the cat, the harder it is to recover from treatment. Most tumors that grow in or on the kidneys are malignant (cancerous). All renal cancers are highly invasive to the body, and over 50% of cases spread quickly. The list of organs and body parts that cancer of the kidneys can spread to is long, including blood, lymph nodes, lungs, brain and spinal cord. Because renal cancer is so aggressive, by the time symptoms have manifested the cancer has already taken hold of the patient. This is a good reason to have routine or annual blood work performed on your cat.

Renal (kidney) cancer is generally rare in cats. Of the cancers that do develop in the kidneys, lymphoma is the most common type to appear, followed by renal cell carcinoma. All renal cancer is very dangerous, requiring immediate treatment. Often, cancer found in the kidneys has metastasized (spread) from elsewhere in the body, making the condition even more serious.  

The symptoms of renal cancer often are shared with other urinary tract problems. If your cat is showing any of these symptoms, it is best to have a vet examine them immediately. Symptoms are as follows:

• Abdominal pain
• Abdominal swelling
• Polyuria (frequent urination)
• Blood in urine
• Polydipsia (increased thirst)
• Nausea
• Vomiting
• Weight loss
• Depression
• Lethargy
• Behavioral changes
• Pale gums
• Dull coat
• Poor skin condition
• Bad breath
• Anemia

Not all renal cancers have an understood cause. It seems that many senior cats eventually develop severe kidney problems. Possible causes include:

• Severe UTI (urinary tract infection) left untreated
• Ingestion of toxins
• Environmental exposure to toxins
• Interaction with a cat who has Feline Leukemia Virus (FeLV is present in almost 50% of renal cancer cases)

A cat's kidneys do not have the tendency to repair well, leading to potential allowances of cancerous irregularities to flourish.

Upon arrival at a veterinary clinic or animal hospital, the veterinarian will request your cat's complete medical history to look for any relative problems. Then, a physical examination and evaluation will take place. All other kidney and liver problems have to be ruled, out as many express the same symptoms. An X-ray or abdominal ultrasound is generally the first thing required to confirm the presence of tumors or irregularities in the kidneys.

If tumors or growths are found, a needle aspiration or biopsy will be needed to examine the properties of said tumors and determine if cancer is present. Extensive blood work will be needed, including a complete blood count and a biochemical profile looking for enzymes with elevated levels. Blood work will also show if the cat is a good surgical candidate or not. Urinalysis will be performed to look for blood traces, high white blood cell numbers, proteins, and even bacteria that could be exacerbating the renal situation. A kidney function test may also be suggested. After all of these tests, an MRI or CT scan will be requested to see if surgery is viable, and if so what the best course of action will be.

Many treatment options are available to cats facing renal cancer. Determining the right treatment will be based on the cancer's progression, the strength of the cat and the type of cancer that is present.

Surgery 

If only one kidney is affected by the cancer, often removal of the entire kidney is advised. This is a high-risk surgery, but offers the best chance of survival if the cancer has not yet metastasized to other parts of the body. The cat will be put under general anesthetic to undergo the surgery. A strict, at-home care regime will need to be administered if the surgery is successful.

Chemotherapy 

This treatment can be lengthy and expensive. Medications that combat cancerous cells will be given to the cat on a regular basis. If the renal cancer present is not lymphoma, chemotherapy may have no significant effect as a treatment.

Radiation Therapy 

This often includes a vigorous schedule of vet administered treatments that can last for weeks on end. It may be used in addition to surgery.

Antibiotics 

After surgery is complete, and if an infection was present at the time of blood work, antibiotics will be prescribed to remove bacteria.

Supportive Care 

In patients that do not qualify for surgery, often general, life assisting care is recommended. This, in turn, becomes palliative treatment to keep the cat comfortable in its last days.

Kidney cancer usually carries an overall poor prognosis in cats. Survival may only be increased by months even after vigorous treatments have been applied. The earlier the cancer is discovered, the better, as this increases the chance of removal before spreading has occurred. There is a very high rate of relapse in renal cancer.

If the cancer is only present in one kidney and has not developed in any other area of the body, and surgical removal of that kidney has taken place successfully, a full recovery is sometimes possible. Extensive at-home care will be required, including a close monitoring of the incision site for possible infection. Later X-rays will be needed to ensure no other cancer is growing, and that the remaining kidney is functioning at an optimum level.