Lymphoma in Cats

Feline lymphoma is the most common of all cat cancers. The disease varies greatly. Some cats manage to live with it for years while others experience rapid progression. Unfortunately, lymphoma isn’t curable. 

Read on to learn more about lymphoma in cats, including the causes and treatment options currently available.  

What is Lymphoma in Cats?

Feline lymphoma is cancer of the lymphocytes, which are specific white blood cells responsible for the production of antibodies to fight infection and disease. 

The disease can appear almost anywhere, as lymphocytes can be found throughout the body. This is why it’s referred to as being ‘systemic’ rather than ‘localized.’

Most Common Types of Feline Lymphoma

The type of lymphoma a cat may develop depends on its location in the body. The most common types are as follows:

• Multicentric: originates in the lymph nodes.
• Intestinal: affects the gastrointestinal tract. (This is the most common type and occurs most often in senior cats.)
• Mediastinal: affects the lymphoid organs in the chest, and is typically seen in young cats.
• Renal: affects the kidneys as healthy kidney cells get replaced by cancerous cells.

High-Grade & Low-Grade Lymphoma

It’s important to note that lymphoma in cats is also classified based on the disease’s progression.

High-grade lymphoma means many of the cells are immature and dividing quickly. The disease spreads fast and is usually unresponsive to treatment. 

Low-grade lymphoma occurs when the cells divide slowly, which means it will likely respond better to treatment options. 

Causes of Feline Lymphoma

The cause of lymphoma in cats is currently unknown, although cats that have Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) face greater risk. Additional research suggests a link between second-hand tobacco smoke  and lymphoma.

Symptoms of Feline Lymphoma

Feline lymphoma can affect a range of organs. There are also several types.

Intestinal Lymphoma Symptoms

• Weight loss
• Vomiting
• Diarrhea
• Changes in appetite

Mediastinal Lymphoma Symptoms

• Respiratory issues including a persistent cough and difficulty breathing.

Renal Lymphoma Symptoms

Renal lymphoma symptoms include signs of kidney failure such as:

• Weight loss
• Decreased appetite
• Increased thirst and urination
• Vomiting

Multicentric Lymphoma Symptoms

• Swollen lymph nodes
• Depression

Note these feline lymphoma symptoms are also indicators of a wealth of other diseases. If your cat has any of them, it’s imperative that you go to your veterinarian for an accurate diagnosis.

Diagnosing Feline Lymphoma

Because the symptoms of feline lymphoma are broad, it’s likely that a series of tests and observations will be required, starting with a physical exam. 

This initial exam checks for swollen lymph nodes or swelling of the gastrointestinal tract. Diagnostic imaging such as an x-ray or an ultrasound to search for evidence of tumors or organ swelling will likely be conducted.

Your veterinarian may also test for FeLV and FIV too because of the link between these diseases and certain types of lymphoma. Surgical biopsies may be required to conclusively confirm the diagnosis of lymphoma.

Treating Feline Lymphoma

Sadly, lymphoma in cats isn’t curable, but treatment can extend your pet’s life and make them more comfortable, depending on its grade and type. 

The best possible outcome is remission, which means that the cancer signs disappear—at least temporarily. However, this doesn’t mean your pet is cured, and there’s a risk the disease may come back.

If your cat is diagnosed with high-grade lymphoma, chemotherapy drugs will likely be administered. During this course, their white and red blood cells will be carefully monitored (as well as other blood parameters). 

As this type of lymphoma is very progressive, response rate is low and the average survival time once diagnosed is 2-4 months. If the lymphoma is localized, which is not very likely, surgery or radiation may be used as a treatment.

For low-grade lymphoma, a selection of chemotherapy drugs are often considered for treatment. The response rate for chemotherapy is generally good and survival time is much higher than that of high-grade lymphoma.

As a pet owner, cancer is never a word you want to hear associated with your feline companion. A speedy diagnosis is imperative to ensure your pet gets the help they need, so if you notice any worrying symptoms, schedule an appointment with your veterinarian as soon as possible. 

Want more cat care tips? Check out our cat health articles for advice from our experts.