Cat Lymphoma Explored by Christopher Pinard, DVM, and Reviewed by Catherine Barnette, DVM, Published on April 15, 2020, with an update on April 30, 2025.
Feline Lymphoma: Types, Symptoms, and Treatment
Lymphoma in cats is a cancer of the lymphocytes, critical white blood cells in a cat's immune system. These lymphocytes are found throughout a cat's body, making lymphoma potentially widespread.
There are several types of lymphoma seen in cats. Among the most common are renal lymphoma, nasal lymphoma, and gastrointestinal (GI) lymphoma.
GI Lymphoma in Cats
Small cell GI lymphoma is one of the most prevalent forms in cats. It is often difficult to distinguish this type of cancer from inflammatory bowel disease (IBD). The transition from IBD to GI cancer can complicate the diagnosis. Small cell GI lymphoma typically results in small intestine thickening and can cause vomiting, diarrhea, or a combination of both.
Large cell GI lymphoma manifests as intestinal or stomach masses, which a vet may detect during a physical examination. This form of GI lymphoma tends to be more aggressive, leading to a cat's health declining more rapidly without treatment.
Nasal Lymphoma in Cats
Nasal lymphoma is another common type in cats, characterized by a tumor or mass that develops in the nasal cavity. This can cause facial deformities, ocular pain, loss of vision, or neurological signs, including seizures. The most common symptoms are sneezing and nasal discharge, which can be mucous-like or blood-tinged.
Renal Lymphoma in Cats
Renal lymphoma affects a cat's kidneys and can extend to the central nervous system. Kidneys affected by this type of lymphoma may have halo-like appearances on abdominal ultrasound and can cause weight loss, increased drinking and urination, and neurological issues.
Other less common types of lymphoma in cats include Hodgkin's-like nodal lymphoma, central nervous system (CNS) lymphoma, and cutaneous (skin) lymphoma.
Infection with viruses such as FeLV or FIV has been associated with the development of lymphoma in cats, though these cases are rare due to routine vaccination and a better understanding of these diseases. Chronic inflammation associated with IBD has also been suggested as a possible predisposing factor for GI lymphoma in cats.
Symptoms of lymphoma in cats depend on the location of the disease, reflecting other diseases as well. Some symptoms include sneezing, vomiting, diarrhea, weight loss, lethargy, seizures, changes in urination or drinking, and changes in behavior.
Diagnosing feline lymphoma is dependent on the location of the symptoms. For GI lymphoma, samples may be obtained through needle biopsies or surgery, while for nasal lymphoma, a CT scan is typically used to evaluate the location of the mass, and biopsies are then obtained. Renal lymphoma is usually diagnosed through ultrasound-guided needle biopsies or in some cases, kidney biopsies.
Treatment for lymphoma in cats depends on the specific type of cancer. Many types of lymphoma will be treated with either systemic therapy (chemotherapy) or local therapy (radiation therapy). Chemotherapy in animals is designed to benefit a cat's quality of life, and side effects are generally less frequent compared to humans.
Surgery is rarely used for feline lymphoma because it is a systemic disease and not usually confined to one site. Radiation therapy can be used for localized lymphoma tumors but is not typically the primary treatment due to the systemic nature of the disease.
Diet modifications, supplements, and emerging therapies can be adjunctive therapies, though their routine use is controversial.
The cost of lymphoma treatment varies depending on geographic area and availability of chemotherapy medications. Discuss the diagnosis and treatment plan for feline lymphoma with your veterinarian and a board-certified veterinary oncologist for the most accurate information.
The goal when treating lymphoma in cats is to improve their quality of life without worsening the disease itself.
- In addition to feline lymphoma being a type of chronic disease, inflammatory bowel disease (IBD) can sometimes resemble small cell GI lymphoma, making the diagnosis more challenging.
- Mental health is important for cats undergoing treatment as symptoms of lymphoma, such as lethargy and changes in behavior, can also be associated with other medical-conditions like depression.
- Health-and-wellness for cats with large cell GI lymphoma requires prompt and aggressive treatment, given the rapid decline in a cat's health that this form of lymphoma often causes without proper treatment.
