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Lymphoma is a cancer that affects dogs and humans alike. Your dog getting diagnosed with canine lymphoma is likely to be a terrifying experience. However, with a better understanding of the condition, you will be in a position to properly manage the situation and make well-informed decisions to improve your pet’s quality of life. Let’s start at the beginning:

Canine Lymphoma Defined

The term “lymphoma” is a blanket reference to a myriad of cancers stemming from the pet’s lymphocytes. The lymphocytes are one of the types of white blood cells that help the animal’s immune system fight infections. Your lymphocytes are part of the lymphatic system. They are concentrated in organs like the spleen, lymph nodes and also bone marrow. While lymphoma can affect any part of the pet’s body, it tends mostly to be found in these particular organs. Canine lymphoma has plenty of similarities to non-Hodgkin’s lymphoma that affects people. The chemotherapy protocols used to treat them are almost all the same.

Type Of Lymphoma In Dogs

There are over 30 of them, each with its signs, level of aggressiveness when it affects the dogs, and varying survival rates. These in turn form 7-14% of all types of cancers diagnosed in dogs. The most common include:

Multicentric lymphoma

This is the most common, accounting for between 80 – 85% of lymphoma cases in dogs. It usually affects the pet’s lymph nodes, which is evident in the enlargement of the nodes—which is actually the most obvious clinical sign.

Here, the lymph nodes can swell between 3 and 10 times their usual size, but they will not be painful. They will have a firm and rubber feel when you touch them, and look like a lump moving under the skin of the affected animal. The dog also becomes lethargic, develops fever, weakness, dehydration and anorexia as the multicentric lymphoma progresses.

Alimentary lymphoma

This comes in second in infection rates, accounting for 10% of the canine lymphoma cases. This type of cancer affects the intestines. Consequently, most of its symptoms witnessed occur here. These are the likes of diarrhea, vomiting, and abdominal pain.

Mediastinal lymphoma

Here, high-grade malignant T lymphocytes in the thymus and the mediastinal lymph nodes cause the affected area to enlarge. This is around the chest. As such, the affected pooch will have breathing difficulties, attributed to the large mass growing in their chest, or pleural effusion—fluid accumulating within the chest. Your dog will probably suffer from increased thirst, which will also lead to frequent urination. The front legs of dogs affected by mediastinal lymphoma may also swell.

Extranodal lymphoma


This lymphoma targets the eyes, kidneys, lungs and other specific organs. It can even affect the central nervous system (CNS). Your dog’s symptoms will depend on the organs that have been affected. The most common of this type of cancer is cutaneous lymphoma, which affects the skin.

In this case, the symptoms will start with red, flaky, and itchy patches that form anywhere on the pet’s body. With the progression of the disease, the skin becomes ulcerated and moist, really red, and it also thickens. Masses on the skin are likely. You’ll find these are either dispersed, or pop up as individual modules on the pet’s body.

It may appear in the mouth as well, affecting the lips, gums and roof of the dog’s mouth. This can often be mistaken for conditions like gingivitis or periodontal disease, especially at the beginning of the illness. On the other hand, if the extranodal lymphoma affects the lungs, then there will be respiratory distress. In the eyes it can cause blindness, while for the CNS the dog may develop seizures.

Causes of Canine Lymphoma

Scientific research is yet to precisely pin-point the causes of lymphoma in dogs. More resources are being pumped into genetic studies to find out the genetic and chromosomal factors and predispositions that result in the condition. However, given that dogs and humans share the same environment, they are also exposed to a majority of the same factors that cause cancers in humans, including magnetic fields and the toxins found in herbicides. It’s also worth noting that a suppressed immune system is an established risk factor for lymphoma development in people. Further research into the immunosuppression link with lymphoma in dogs is required.

Diagnosis Of Lymphoma In Dogs

You’ll need to get a confirmatory diagnosis if you even suspect your dog has this type of cancer. It’s necessary to take a sample of the affected organ from your pet. Fine-needle aspiration, where the sample is extracted from affected organs or lymph nodes, is the normal approach. Follow up is done through Histopathologic tissue evaluation, or a cytology exam.

A positive diagnosis will result in the need for staging tests. This will establish how far the cancer has spread through your dog’s body. This gives the vet a better understanding of the overall condition of the dog and the state of the cancer. These tests range from urinalysis, blood tests, sonograms of the pet’s abdomen, all through to bone marrow aspiration.

Treatment Of Canine Lymphoma

Chemotherapy is the preferred method. Your vet will recommend the specific type of procedure to treat lymphoma. Prescription of therapy protocol UW-25 is bormal in dogs with multicentric lymphomachemo. Treating this condition with the combination of chemotherapy drugs is usually successful, with even 90% of dogs with high-grade, multicentric canine lymphoma getting to complete remission, where the tumors are completely reduced.

On the other hand, Lomustine (CCNU) is often the chemotherapy protocol adopted for the treatment of cutaneous lymphoma. You will discover that it’s difficult to treat some forms of lymphoma, such as alimentary lymphoma. Surgery will be necessary to remove the tumor. Usually in combination with chemotherapy medication. Your dog will benefit from the use of radiation therapy to target cancerous cells.

Side Effects

You’re likely to be concerned about the side effects of chemotherapy on your pooch. However, which dog chemo, they don’t usually get as sick as people do, making them tolerate chemotherapy better than us. They also rarely lose their hair, except for breeds like Old English Sheepdogs and Poodles. As a side effect to the chemotherapy, the dog may have a low appetite, mild vomiting and diarrhea, and activity levels will be lower than usual.

Boy sitting in front of dog. Part of the "Lymphoma In Dogs: From Identifying To Managing The Cancer" article.
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The shock that comes with your furry friend getting a confirmed lymphoma diagnosis is hard to deal with. However, talking to your vet about the different treatment options that are available, and issues that you should expect as the particular type of cancer progresses will enable you to pick the treatment program and management practices that will improve your furry friend’s quality of life, for you to enjoy your previous moments together.

Would you like to read more about common types of cancers in dogs? Please click on this link to go to this article. 


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