Lymphoma in dogs


  • Lymphoma is a cancer of lymphocytes, a type of white blood cell.
  • These cells travel around the whole body, which means lymphoma can be found in many different parts of the body including the lymph nodes (glands), spleen, liver, or skin.
  • The most common type of lymphoma is when your dog has swollen lymph nodes (glands) under their jaw and elsewhere. They usually seem well otherwise.
  • Other symptoms of lymphoma can include drinking and peeing more, weight loss, and low energy. The symptoms vary, depending on what type of lymphoma your dog has and where it is.
  • If your dog is diagnosed with lymphoma, it might be possible to treat it to make your dog feel better and to give them more time but sadly, the condition is eventually always fatal.
  • Contact your vet if you notice your dog has big lymph nodes (glands).

General information

Lymphoma is a cancer of lymphocytes, a type of white blood cell. White blood cells protect the body against illness and disease. Lymphoma is most commonly found in the lymph nodes (glands) but it can also affect the liver, spleen, bone marrow, thymus, kidneys, digestive system, and skin.

If your dog has lymphoma, their survival time will depend on which type they have, where it is, how aggressive it is, how far it’s spread, and the symptoms it causes.

Lymphoma often develops in middle-aged dogs (6-9 years old) but it also occasionally affects very young dogs. There is an increased risk in certain breeds such as Golden Retrievers, German Shepherds, Scottish Terriers, and Boxers.


Symptoms of lymphoma vary depending on what type it is, where it is and how aggressive it is. Most dogs show few or no symptoms except for lymph node (gland) enlargement.

Possible symptoms include:

Lymph nodes are part of the lymphatic system (which is part of the immune system, helping to fight off illness) and are located all over the body. Some lymph nodes are in the tummy and chest and can’t easily be felt, others are under the chin and in the armpits and are more easily felt. Lymphoma can affect some or all of the lymph nodes at the same time.

Most of these symptoms can also be caused by other illnesses. If your dog is showing any of these symptoms, it is best to contact your vet for an appointment.

Illustration of lymph nodes

The diagram above shows the lymph nodes (glands) you can easily feel in your dog: under the jaw, in front of the shoulder, in the ‘armpit’, in the groin and behind the knee. Click image to enlarge.

Diagnosis – grading and staging

To confirm a diagnosis, decide on the best treatment plan, and to give a prognosis your vet may advise doing certain tests to grade and stage your dog’s lymphoma:

  • Grading - tells us how aggressive the lymphoma is by taking a sample of tissue from the lump.
  • Staging - tells us how far the lymphoma has spread. There are 5 stages – stage 1 has just one lymph node affected, whereas stage 5 is when the cancer has spread to the bone marrow and other organs. Blood tests, x-rays, and ultrasound scans are needed to stage lymphoma.

The tests are likely to involve:

  • Taking a sample of tissue from the tumour which can be done in two ways:
    • Fine needle aspirate (FNA) – a simple, quick procedure, usually done without sedation or anaesthesia. A small needle is used to get cells from the lump which are then examined under a microscope.
    • Biopsy – involves taking a bigger sample of the lump and sometimes the whole lump is removed. A bigger sample means it may be possible to get more information on the type of lymphoma, treatment options and prognosis. This is likely to be done under sedation or general anaesthesia.
  • X-rays and scans
  • Blood tests

Your vet may need to refer your dog to a specialist veterinary centre for full diagnosis and treatment.

Treatment and outlook

Without treatment

Sadly, without treatment, many types of lymphoma are fatal within . In very rare cases, a certain type of lymphoma called indolent lymphoma can show mild symptoms on and off and your dog’s lifespan can be months to years.


Steroids can reduce symptoms and may extend your dog’s lifespan for a few weeks or months. They can make your dog feel better, however, if given as the only treatment, especially for the more aggressive types of lymphoma, they will usually only work for a short time.


Chemotherapy drugs attack and kill cancer cells. The aim of using chemotherapy is to ensure a good quality of life and achieve remission (when the disease is not completely gone but we cannot detect it) – but it is unlikely to be a complete cure.

In some cases, chemotherapy can extend your dog’s lifespan from a few months to a year or more. Some types of lymphoma respond very well to chemotherapy and many dog’s tolerate having chemotherapy very well with minimal to no side effects.

However, response varies a lot and it is important to know that each case of lymphoma is different and every dog will respond differently. Unfortunately, some types of lymphoma don’t respond well to chemotherapy. Even if your dog responds well, they are very unlikely to be cured completely. They may go into remission for a period of time and live longer than they would have done without treatment, but eventually their cancer will return. It is also important to consider how your dog will cope with chemotherapy, as it usually involves multiple visits to your vet, often with blood tests and injections, which some dogs may find stressful.

It’s important throughout chemotherapy that your dog’s quality of life is good. Treatment usually involves combining different types of drugs which may be an injection, tablets or a combination of both. It’s often given over a long period of time for example up to six months. The cancer can eventually become resistant to treatment which means it comes back again. While chemotherapy can have side effects, in dogs these tend to be mild. Your vet will discuss any potential side effects linked to the specific medication your dog is on.


Your vet might advise surgery in some circumstances for example removing the spleen. However, this isn’t very common as it depends on where the lymphoma is whether or not it is a suitable option for your pet. It may also be used alongside chemotherapy.

Radiation therapy

Radiation is only used in specific types of lymphomas for example skin lymphoma.

Other treatments

One complication of lymphoma can be high calcium in the body which also needs to be treated as it can make your dog very poorly and complicate managing the illness.

It’s very important to consider your dog’s outlook and quality of life when deciding on what treatment they will have. Certain things might influence your decision such as access to a specialist vet if this is needed, cost of treatment, and how well you feel your dog will cope with the treatment – which may involve lots of visits to the vets. Some dogs are happy to go the vets and others may find it stressful. Your vet will help you decide what is best for you and your dog.

When to euthanise

Sadly, if your dog is suffering with lymphoma and treatment isn’t helping or you decide not to treat as you feel your dog is suffering, it may be kinder to put them to sleep. Many owners find this a very difficult decision to make, which is why your vet is always there to guide and help you through the process of making the decision. Your vet will make sure you make the right decision at the right time.

When to contact your vet

Contact your vet for an appointment if your dog has any of the symptoms above, especially if you can feel big, swollen lymph nodes.

You know your dog best, always contact your vet if you’re concerned.


Treatment for lymphoma can become very expensive, so it’s important to speak openly with your vet about the cost of treatment, your finances, and what you think is right for your dog. There is sometimes more than one treatment option, so if one doesn’t work for you/your pet then your vet may be able to offer another. It can be difficult to predict overall cost initially as it depends on your dog’s individual response to treatment, side effects and time of relapse.

When you welcome a new dog into your life, consider getting dog insurance straight away before any signs of illness start. This will give you peace of mind that you have some financial support if they ever get sick. 


What are the side effects of chemotherapy for my dog?

Side effects of chemotherapy are rare and usually very mild but can include vomiting, diarrhoea, reduced appetite, and cystitis (inflammation in the bladder). Most dogs don’t lose their fur while having chemotherapy.


My dog doesn’t seem unwell – do they need to start chemotherapy straight away?

Yes, the first symptoms of lymphoma in many dogs are swollen lymph nodes (glands) and they often otherwise still seem well. If your dog is diagnosed with lymphoma and you decide to treat with chemotherapy, it’s important to start the course of treatment as soon as possible.

Will my dog need to see a specialist vet?

This can vary. Some vets will have experience and the facilities needed to diagnose and treat lymphoma and will be able to offer treatment in your usual vet practice. Other practices may not have the facilities needed to diagnose and treat lymphoma, and in these cases they will recommend referring your dog to your local specialist referral centre.

Will chemotherapy make my dog lose their hair?

It’s very rare for your dog to lose their fur while having chemotherapy.

How will I know when the lymphoma returns?

If your dog has had a course of chemotherapy treatment and has gone into remission, the symptoms they might show if their lymphoma has returned may be similar to the symptoms that they initially had when you first noticed they were ill. However, it’s important that if you notice anything unusual about your dog or they are generally off form, to contact your vet for advice.

Can chemotherapy be given at home?

Chemotherapy treatment protocols are usually a combination of a few different medications which can includes tablets and injections. The injections will need to be given at your vet practice and your vet will be able to advise on how often this will be depending on which protocol your dog is on.

Is it ok for me to handle chemotherapy drugs at home?

Some chemotherapy protocols involve giving tablets to your dog at home. If you decide to go ahead with chemotherapy for your dog, you will be advised on precautions to take at home for example using gloves to handle the medications and your dog’s wee and poo. Children and pregnant women must not come into contact with the medication or wee/poo from your dog while they are on treatment. It’s important to discuss specific precautions with your vet before your dog starts on treatment.

Published: January 2024

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.