Renal lymphoma is a cancer of the lymphocytes (red blood cells involved in the immune system) that affects a cat’s kidneys and can potentially extend to the central nervous system.
Cats suffering from renal lymphoma typically have enlarged, firm kidneys that present a characteristic halo-like appearance on abdominal ultrasound. Renal lymphoma at advanced stages will lead to renal failure.
Causes of renal lymphoma in cats
Infection with feline viruses such as FeLV or FIV has been associated with the development of lymphoma in cats, including renal lymphoma. Inflammation associated with chronic inflammatory bowel disease has also been identified as a possible predisposing factor for the disease, especially gastrointestinal lymphoma.
The constant movement of the lymphocytes through the lymph system means lymphoma is rarely a localized disease. The affected lymphocytes in one part of the body will be carried to another. For example, lymphocytes from the gastrointestinal or nasal tissues will eventually end up in the kidneys.
It’s vital to note that the development of lymphoma is complex and multiple events and lifestyle factors play a role. The good news, however, is that cases of viral-induced renal lymphoma in cats can be prevented with the use of vaccines.
Symptoms of renal lymphoma in cats
Clinical signs of renal lymphoma in cats include:
- Weight loss
- Increased thirst/drinking
- Excessive urination
- Reduced appetite
- Enlarged left kidney
Diagnosis of renal lymphoma in cats
In order to determine whether a cat has renal lymphoma, a veterinarian may have to perform a baseline screening bloodwork to assess the cat’s overall health. This also helps them rule out other possible causes of the clinical signs your cat is presenting.
Diagnosing renal lymphoma often involves the use of a fine needle aspirate. The procedure involves the insertion of a needle into the enlarged area, often the kidney, to remove a small number of cells for microscopic examination. While the use of needle aspirate doesn’t yield high-quality diagnostic samples, it’s preferred because the procedure carries minimal risks, costs, and side effects.
In case the needle aspirate procedure yields inconclusive results or is impossible to do for whichever reason, the veterinarian will likely perform a surgical biopsy. It involves removing a piece of tissue from the affected area and a microscopic examination done to assess lymphoma.
Once the diagnosis is done and the findings indicate your cat has renal lymphoma, your veterinarian will proceed to determine whether the condition is high-grade or low-grade. This determination is based on how malignant the cancer cells appear to be and the rate at which they divide.
Low-grade renal lymphoma in cats is more likely to respond to chemotherapy treatment with the possibility of a longer remission. The opposite is true for high-grade renal lymphoma.
Treatment for renal lymphoma in cats
Renal lymphoma is an aggressive form of cancer that often requires the use of chemotherapy with a CHOP-based protocol. Radiotherapy and surgery are less effective because affected lymphocytes are not localized.
The treatment reduces enlargement of the kidney and kidney functions improve for the duration the cat is in remission. The good thing is that cats can tolerate chemotherapy better than humans and rarely lose their hair (fur).
Based on research studies, approximately 60-70 percent of cats receiving chemotherapy treatment for renal lymphoma will experience clinical improvements, which includes going into remission. About 10 percent of cats experience side effects when undergoing the treatment, which includes vomiting, diarrhea, and decreased appetite.
If chemo is not an option due to the cat’s health condition, prednisone can be used for hospice or palliative care. Prednisone is not a treatment of the disease but provides a temporary reduction of the clinical signs.
It’s vital to note that approximately 50% of cats with renal lymphoma are likely to test positive for the feline leukemia virus, which is likely to cause other health complications.
Renal lymphoma prognosis in cats
Sadly, renal lymphoma in cats carries an unpleasant prognosis. The average survival time of cats suffering from this condition is only 4-7 months. There are, however, a few isolated cases where cats can survive for up to a year.
Renal lymphoma also has a tendency to spread to the central nervous system, which occurs in approximately 40% of cats suffering from the disease. The spread of the sick cells worsens the prognosis hence reducing projected lifespan.
How to prevent renal lymphoma in cats
While it’s almost impossible to prevent your cat from suffering from renal lymphoma, there is one thing you can do to reduce the chances of this happening. You should prevent feline leukemia virus infection by having your cat vaccinated against the feline leukemia virus. This will help prevent feline leukemia infection, which in turn reduces the risks of your cat suffering from renal lymphoma.
Facts about renal lymphoma in cats
A few facts worth keeping in mind as far as renal lymphoma in cats is concerned include:
- The tumor is more likely to spread to the nervous system (brain and spinal cord)
- Tumor spread has been observed in approximately 40% of the sick cats
- Cats with renal lymphoma can live for between 4-7 months, though some live longer
- The significant kidney damage from renal lymphoma means the metabolism of chemotherapy drugs will be affected due to reduced renal efficiency
- Significant kidney damage also means the renal damage is likely to be progressive even when undergoing chemotherapy or when the cat is in remission
- The spread of the renal tumor to the central nervous system causes other health complications hence reducing the cat’s lifespan
Renal lymphoma in cats is the most fatal type of lymphoma cats can get. While there is little you can do to prevent your cat from suffering from the condition, it’s advisable to have them vaccinated against the feline leukemia virus. This will help protect your cat to some extent.