At our veterinary clinic in Lebanon, we frequently encounter lymphoma in cats, which is a form of cancer that affects lymphocytes, a type of white blood cell in their body. In this article, we will delve into the various types of lymphoma that affect cats, the methods used for diagnosis, and the treatment options available for this condition.
What is lymphoma in cats?
Did you know that lymphoma is a type of cancer that affects the lymphocytes in a cat's immune system? These cells are found in the blood and lymphatic vessels and travel throughout the body. It's commonly associated with feline leukemia, but thanks to vaccination efforts, both diseases are becoming less common. However, lymphoma still accounts for about 30% of all cancer cases diagnosed in cats.
Where is lymphoma typically found in cats?
Lymphocytes are present in various organs of your cat's body, increasing the likelihood of lymphoma affecting multiple areas. The disease typically develops in the cat's nasal cavity, gastrointestinal tract, or mediastinal region. Classification of your cat's lymphoma will be based on the location of the disease and the size of the lymphocytes, which can be small or large cells.
- Intestinal lymphoma is the most common form of lymphoma in cats. This cancer is found in the GI tract and is most often seen in cats over 9 years of age.
- Mediastinal lymphoma affects the lymphoid organs found within the cat's chest. These organs include the lymph nodes and the thymus. Strongly associated with feline leukemia, this form of lymphoma is typically seen in cats around 5 years of age.
- Renal lymphoma is also associated with feline leukemia. Renal lymphoma affects the cat's kidneys and may result in kidney failure.
What are the most common symptoms of lymphoma in cats?
Your cat's lymphoma symptoms will depend upon where the cancer is located.
- A cat with intestinal lymphoma will often experience diarrhea, weight loss and vomiting. In cats with large cell intestinal lymphoma these symptoms can come on very rapidly, in a matter of just days or weeks, whereas cats with the small cell version of the disease will show a much slower onset of symptoms.
- Because mediastinal lymphoma is found in the cat's chest area breathing difficulties are a common symptom of the disease. In some cases fluid can build up around the tumor making it increasingly difficult for the cat to breathe
- As toxins build up in the blood system, cats with renal lymphoma will show common symptoms related to kidney failure including vomiting, reduced appetite, and increased thirst. In some cases the cat's central nervous system may be affected, in which case symptoms such as seizures, instability while walking and behavior changes may occur.
How is lymphoma in cats diagnosed?
When it comes to diagnosing lymphoma in cats, veterinarians typically choose between fine needle aspiration cytology or a biopsy, depending on the severity and location of the disease. In some cases, vets might have to obtain samples from other organs or conduct molecular testing on tissues or blood to confirm the lymphoma diagnosis. There could also be a requirement for additional diagnostic procedures.
- Bloodwork such as CBC (Complete Blood Count) and full chemistry panel
- Testing for feline leukemia FeLV/FIV
- Urinalysis
- Ultrasound imaging to evaluate the cat's GI tract, spleen, liver and lymph nodes
- X-rays to evaluate lungs and lymph nodes
What is the treatment for lymphoma in cats?
If a cat is diagnosed with lymphoma, chemotherapy is often the first line of treatment. However, radiation therapy and surgery, with or without chemotherapy, may also be considered if the lymphoma is limited to a specific area like the nasal region or abdomen. Your veterinarian or veterinary oncologist can suggest the most suitable treatment based on your pet's unique condition. In cases where chemotherapy is not feasible, prednisone might be prescribed for palliative or hospice care.
What is the prognosis for cats diagnosed with lymphoma?
Cats diagnosed with gastrointestinal large cell lymphoma can have a prognosis of 6-9 months with treatment. Although rare, a small percentage of cats who reach full remission with treatment can live up to 2 years. For cats diagnosed with small cell gastrointestinal lymphoma, ongoing care with oral medications is necessary, but they could live 2-3 years or longer with the disease.
Unfortunately, cats diagnosed with mediastinal lymphoma and feline leukemia have a poor prognosis of about 3 months. However, cats without feline leukemia who have mediastinal lymphoma may respond fully or partially to chemotherapy and have an average survival time of about 9-12 months. Regrettably, renal lymphoma has a very poor prognosis, with an average survival time of only 3-6 months.
Although there are isolated reports of cats surviving longer, renal lymphoma has a tendency to spread to the brain and central nervous system, which worsens its prognosis. Without chemotherapy, large cell lymphoma in cats can progress quickly and result in fatality. Palliative treatments may extend a cat's quality of life by a few weeks or months.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.