Gastrointestinal lymphoma in cats

Gastrointestinal lymphoma is one of the most common types of lymphoma in cats. Most commonly, it affects the small intestine, but it can also involve any part of the gastrointestinal tract, from the rectum to the esophagus.

Unfortunately, gastrointestinal lymphoma in cats isn’t curable, but with effective treatment, many cats can enjoy a normal quality of life for a period of time.

In this article, we’ll discuss the symptoms of gastrointestinal lymphoma, in addition to the diagnosis, treatment and prognosis of it.
 

What is gastrointestinal lymphoma?

Lymphoma is a cancer of white blood cells (lymphocytes). Lymphoma can occur anywhere in the body, but in cats it is commonly found involving the stomach or intestines (gastrointestinal tract).

Gastrointestinal lymphoma can be classified in different ways, but one of the most important classification schemes refers to certain characteristics of the cancerous cells, specifically how quickly they are dividing. High grade lymphoma refers to a lymphoma where the cells are relatively immature (lymphoblasts) and hence dividing quickly. There tumours tend to spread quickly, and for the gastrointestinal form, respond relatively poorly to treatment. Low grade lymphoma contains cells that are dividing quite slowly; this type of tumour tends to spread slowly and can respond quite well to treatment (although unfortunately treatment is never curative). A third type of lymphoma, called large granular lymphoma (LGL) is also found affecting the gastrointestinal tract in cats. This type of lymphoma also contains rapidly dividing cells and does not tend to respond well to treatment.

As such, depending where on the spectrum the lymphoma is, some cats can live for some time without feeling ill at all; whereas sadly for others, it can become rapidly progressive and fatal.

While lymphoma can affect cats of any age age,sex and breed, it generally affects older cats, and Siiamese cats may be predisposed. While there are no specific causes, research has found that cats with FIV are over five times more likely to develop lymphoma than FIV negative cats. Feline leukemia virus (FeLV) infection can also predispose cats to lymphoma, but due to screening programs, infection with FIV and FeLV is much less common nowadays and most cats with gastrointestinal lymphoma are not infected with these viruses.
 

Gastrointestinal lymphoma in cats: symptoms

Much like lymphoma in dogs, symptoms and severity can vary between cats. However, the most common symptoms include chronic diarrhoea, vomiting, weight loss and constipation.

It’s therefore important to have gastrointestinal lymphoma on your radar, and if your cat exhibits any of these symptoms (especially unexplained weight loss), then take them to your GP vet to be assessed.
 

Diagnosis of gastrointestinal lymphoma

When your cat attends a physical examination, we may identify intestinal thickening or subtle abdominal mass. However, there may be no abnormalities identified until we conduct an ultrasound or a computed tomographic (CT) scan.

Once we’ve carried out the scan, we’ll sample the abnormalities, which can be done in several ways, and is largely dependent on the location and presentation of the lymphoma:

  • Cytology: An ultrasound guided FNA for cytology is the least invasive way of sampling the abnormalities. If the intestinal wall is accessible and thick enough, we’ll test that – otherwise we will take a sample from the cat’s enlarged lymph nodes. If the cytology is ambiguous, further testing to see if the cells are all genetically identical (a clonal proliferation) called a PARR analysis, can support a diagnosis of lymphoma
  • Endoscopy: An endoscopy can be carried out on cats who have gastric, colonic or duodenal lesions. However, we would first need to ensure that the thickening is affecting the inner intestinal layers.
  • Surgical biopsy: We’ll only carry out surgery as a last resort, if we believe it will help the cat, or if we’ve exhausted all other options.

 

Treatment and prognosis of gastrointestinal lymphoma in cats

The treatment and prognosis is largely dependent on the type of gastrointestinal lymphoma as outlined above.

If your cat has been diagnosed with low grade lymphoma, then we’ll usually prescribe chlorambucil and prednisolone. Prognosis tends to be better for cats with this grade, with an average survival rate of approximately two to three years.

For cats that have high grade lymphoma other forms of chemotherapy are available. We tend not to perform surgery unless there is a visible obstruction or perforation of the bowel, as lymphoma tends to be very diffuse and complete removal is not possible. Unfortunately, response times and survival tends to be short lived (usually 2-4 months)

Unfortunately, for cats suffering from LGL lymphoma, the prognosis is similarly poor. Similarly to high grade lymphoma, there are a variety of chemotherapy options available, but survival tends to be short lived (1-3 months)

It’s important to understand that chemotherapy won’t cure your cat. However, what it will do, is help to preserve their quality of life for as long as possible.

No one wants to hear their cat is ill and won’t recover, but by understanding the available treatment and prognosis, you can help to improve your cat’s quality of life, and better understand your role in the treatment process.
 

How to ask for a referral to Swift

If you’re worried your cat may be suffering from gastrointestinal lymphoma, then book an appointment with your GP vet. If they diagnose your cat after having assessed them, you can ask them to refer you to our internal medicine team, where we can treat your cat. Find out more about the referrals process here.

Alternatively, for more information about common illnesses, surgery and treatments for cats and dogs, head on over to our blog.

Got a question? We can help.

Let us know if you have any questions, and our client care team are on hand to answer any questions about our practice, the referrals process and what you can expect.