Sometimes our cats are affected by conditions that we don't see coming, even with routine care. One of these conditions is lymphoma which affects the white blood cells of your cat. In today's blog, our Corpus Christi vets discuss the causes, signs, and treatment of lymphoma in cats.
How Lymphoma Affects Cats
Lymphoma is a systemic cancer that affects the lymphocytes of the cat's immune system. Lymphocytes travel through your cat's body in the blood and lymphatic vessels. This condition is associated with the viral infection of feline leukemia.
Thanks to increasing numbers of cats being immunized against feline leukemia as part of the annual wellness and vaccination care, both feline leukemia and lymphoma are becoming less common than they once were, although there is still much room for improvement. When it comes to lymphoma, approximately 30% of all cats will be diagnosed at some point in their life.
Where Lymphoma Develops
Lymphocytes are present throughout your cat's body which means that this cancer can develop in any organ or area of your cat.
Some of the commonly seen affected areas include the cat's nasal cavity, gastrointestinal tract, or mediastinal. Your cat's lymphoma will be classified based on the location of the disease and the size of the lymphocytes, which can be either large cells or small 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.
Signs of Lymphoma in Cats
The symptoms that your cat will experience with lymphoma will depend on where the cancer has affected the body. Here are some of the symptoms based on location:
- 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.
Diagnosing Feline Lymphoma
Depending on the extent of the disease and the location, either fine needle aspiration cytology or a biopsy will typically be used to diagnose lymphoma in cats.
In some cases, vets may require sampling of bone marrow or other organs, or molecular testing on tissues or blood to provide a definitive diagnosis of lymphoma.
Diagnostics may also include:
- Bloodwork such as CBC (Complete Blood Count) and full chemistry panel
- Testing for feline leukemia FeLV/FIV
- Ultrasound imaging to evaluate the cat's GI tract, spleen, liver, and lymph nodes
- X-rays to evaluate lungs and lymph nodes
Treating Lymphoma in Cats
The most common method of treatment for lymphoma in cats is chemotherapy. Although radiation can also be an option and surgery (with or without chemo) if the disease is only present in a single area of your cat's body.
Your veterinarian or veterinary oncologist will be your best source to determine which treatment method will be best for your kitty.
There may be situations where chemotherapy is not an option and prednisone may be prescribed as palliative or hospice care.
The Prognosis for Feline Lymphoma
With treatment, the prognosis for cats diagnosed with gastrointestinal large cell lymphoma is about 6 - 9 months. While rare, some cats may experience full remission and potentially live up to 2 more years.
Cats diagnosed with small cell gastrointestinal lymphoma will require ongoing care with oral medications but could live 2 - 3 years with the disease or longer.
Sadly, cats diagnosed with mediastinal lymphoma and feline leukemia face a poor prognosis of about 3 months.
Cats that do not have feline leukemia, who are diagnosed with mediastinal lymphoma, may show a full or partial response to chemotherapy. These cats have an average survival time of about 9-12 months.
Renal lymphoma, unfortunately, carries a very poor prognosis. Average survival with this type of lymphoma is only 3-6 months, though there are isolated reports of cats surviving far longer. Renal lymphoma tends to spread to the brain and central nervous system; this occurs in approximately 40% of renal lymphoma cases and worsens the prognosis for this disease.
If not treated with chemotherapy, large cell lymphoma in cats will progress very quickly and soon be fatal. Palliative treatments may help to extend the cat's quality of life by a few weeks or possibly 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.