Signs, Causes, and Care for Dog Lymphoma: When to Euthanize?

🦴 Updated on July 3rd, 2023


Canine lymphoma is a type of cancer that roughly 20 percent of middle-aged to older dogs become diagnosed with. At first, there are no significant signs; however, it can be a very emotional time for your dog and your household as it progresses.

My dog Lucy was diagnosed with lymphoma earlier this year. Starting almost six months ago, I noticed Lucy had swollen lymph nodes. Had I known more about canine cancer, I would have gotten her into a vet sooner for a quicker diagnosis.

My first thought was that she could be stressed as we introduced a new human member to our family just under a year ago. Lucy acted like her playful, happy self, but I decided she should see a vet just in case. 

Throughout this article, I would like to discuss the importance of lymphoma. Lymphoma is treatable. However, it takes knowledge about the process, signs, and care to get your canine into remission to help them live their full and happy lives. 

What is Canine Lymphoma?

Lymphoma is a type of cancer that attacks the lymph nodes and lymphocytes (white blood cells), responsible for helping fight infection. 

Canine lymphoma is the most common cancer in dogs and is the closest related cancer known as non-Hodgkin’s lymphoma (NHL) diagnosed in humans. 

The lymphatic systems are organs and blood cells that work together to move fluids and keep your immune system high. Lymphoma attacks the body’s immune system and other organs to the point where the body starts to shut down slowly. 

The main lymphoma areas found in a canine are the lymph nodes, spleen, throat, and bone marrow. Although there are over 30 different types of lymphoma, the most common are:

  • Alimentary
  • Multicentric
  • Extranodal
  • Mediastinal

Alimentary Lymphoma

5 to 10 percent of all lymphoma cases are classified under the alimentary lymphoma condition. Alimentary lymphoma attacks the intestines of your dog. Some symptoms of alimentary lymphoma are loss of control over bladder movement and excessive vomiting.

Multicentric Lymphoma

Multicentric lymphoma has a higher rate, accounts for up to 80 percent of the disease, and is the most common of lymphoma cancers. Multicentric attacks the lymph nodes and immune system organs. 

The first detection of multicentric lymphoma includes the jaw, in front of the shoulders, under the arm, and near the groin and legs. 

Extranodal Lymphoma

Extranodal lymphoma in dogs targets specific organs such as the eyes, lungs, or nervous system. Perhaps the rarest lymphoma is extranodal and can only be diagnosed by taking large quantities of DNA such as blood or tissue and bone marrow. 

Mediastinal Lymphoma

Roughly 50 percent of lymphoma cancers in dogs are classified as mediastinal. Mediastinal lymphoma causes labored breathing and coughing and usually targets the chest cavity and thymus gland. 

What Causes Lymphoma in Dogs?

Just like humans, dogs have cancerous cells moving throughout their bodies. Some may never experience the debilitation cancers effects cause while others cells become cancerous, which therefore spreads. 

There is no known factor to what causes lymphoma. It is still being closely studied that environmental factors such as toxic substances, bacteria, and chemical exposure are the culprit. 

In humans, some scientists believe suppression of the immune system may be the cause for diagnosed cancer; however, the same evidence does not conclude for dogs experiencing lymphoma.

Beginning Symptoms of Canine Lymphoma

Canine lymphoma may be challenging to examine or notice in the beginning stages. Your dog will rarely show any fatigue symptoms or show that there is anything wrong. However, the beginning stage of lymphoma are:

  • Swelling in the jaw, behind the knee, or shoulder
  • Itchy redness in the swollen regions
  • Dry or flaky skin in specific body parts

Although the above symptoms can stem from injury, illness, or another medical reason, it’s best to seek a veterinarian’s advice for further testing. 

Depending on the type of lymphoma your dog has, each beginning symptom will be different.

Beginner Multicentric Symptoms

  • Swollen lymph nodes
  • Fever
  • Weakness
  • Dehydration

Beginner Alimentary Symptoms

  • Diarrhea
  • Weight loss
  • Vomiting

Beginner Mediastinal Symptoms

  • Difficult breathing while running or playing
  • Facial swelling
  • Increased thirst

Beginner Extranodal Symptoms

  • Swelling in the lymph nodes accompanied by scaly skin
  • Bright red gums or roof of the mouth
  • Skin lesions

Dog Lymphoma End of Life Symptoms

As canine lymphoma persists, a dog’s meaning and purpose in life significantly decrease. End-of-life symptoms will begin to show which you’ll see the main difference in behavior and attitude. 

Some dogs become aggressive and confused, while others become highly affectionate and oblivious to their environment. 

Initially, the most common end of life symptoms of lymphoma (no matter the type) include:

  • Labored breathing
  • In and out of consciousness
  • Restless and uneasy
  • Inability to stand or move
  • No drive to be playful
  • Inability to control bladder or bowel movement
  • No appetite
  • Disorientations – as if they are looking through you

The above symptoms are not only signs of dog lymphoma end-of-life symptoms. They are also common ailments for general end-of-life stages. 

If you’re wondering when to put a dog down with lymphoma, the above discomforts are sure signs that your dog will not get better, and euthanization should become a close consideration. 

How is a Dog Diagnosed with Lymphoma?

If you suspect cancer in your dog, a vet can examine and diagnose lymphoma by proceeding with a few tests. 

One test requires extraction through a fine needle called a cytology exam. The other method requires an incision from the swelling site. Both tests help the vet determine if cancerous cells run through your dog’s body.

If the tests show cancerous cells, your dog will then be diagnosed with lymphoma if these cells are located in the lymph nodes. 

After your dog has been diagnosed with lymphoma, it’ll require more testing to determine how far cancer has progressed. Further testing includes urinalysis, blood work, and sometimes X-rays. 

Depending on the stage defined, it will depend on the type of treatment your vet recommends. 

Dog Lymphoma Life Expectancy

Most dog owners think, “my dog has lymphoma; when should I put him down?” First, you’ll want to follow the vet’s recommendations to forego treatment as there is always the possibility that your dog will recover and go into remission. 

Remission is when cancer has been reduced by at least 50 percent and no longer affects your dog’s quality of life. However, there is a chance cancer could return.

The prognosis of canine lymphoma largely depends on the stage where their cancer is and how rapidly it’s growing. On average, the prognosis is usually no longer than a year with treatment. 

If you choose not to follow through with treatment, you can expect to say goodbye within one month. Although chances are higher for your dogs’ survival rate with treatment, often many dog owners choose to euthanize out of fear their dog will suffer for longer than they need to. 

The main reason your vet will recommend treatment for your dog is due to the chance of going into remission so that your canine friend will recover and live out its life. On the other hand, there is no sure way to tell whether your dog will survive. 

Lymphoma Grades, Stages, and Progression

Lymphoma has five stages. Stages 1 and 2 are rarer, while stages 3 to five are most common. 

  • Stage One: One individual lymph node is infected
  • Stage Two: Multiple lymph nodes are exposed to cancerous cells on one side of the body
  • Stage Three: Multiple lymph nodes are exposed to cancerous cells on both sides of the body
  • Stage Four: Multiple lymph nodes are exposed to cancer inside the liver or spleen on one or both sides of the body
  • Stage Five: The most aggressive stage – all parts of the body such as bone marrow and central nervous system has become affected by lymphoma

Lymphoma travels through lymph vessels affecting many organs within your dog’s body. The progression of lymphoma travels more rapidly the higher the stage of cancer. Your dog’s nodes are swollen because lymphoma blocks fluids from going to that site. 

Symptoms of Final Stages of Canine Lymphoma

If you have chosen to forego treatment for your dog, your life will change significantly. Treatment is critical as the survival rate for canine lymphoma considerably increases by 80 percent. 

On the other hand, there are common warning signs you’ll notice when it’s time to come to the acceptance that your dog will not survive their cancer:

  • Total loss of appetite
  • Frequent seizures
  • No energy or drive to move
  • Depression and anxiety
  • Ongoing high fevers
  • Constant shaking
  • Trouble breathing such as panting with small movements
  • Trouble walking

Your vet will keep you updated throughout the treatment process for the health and safety of your dog. When your vet feels it may be time to consider euthanization, they’ll let you know.

How to Make a Dog with Lymphoma Comfortable

Caring for a dog diagnosed with lymphoma is a complicated and emotional battle between never knowing if your dog will go into remission or when it’ll need to be put down. However, there are ways that you can make your dog feel loved, validated, and comfortable during the process.

The goal is to allow your dog to feel comfortable through light exercise, safe playtime (light activities), and tools to help them through their sickness. Some tools require pet ramps, harnesses to help them walk, dog diapers, and dog wheelchairs. 

When to Put a Dog Down with Lymphoma

When do you put your dog down if they have been diagnosed with lymphoma? This is a question many dog owners ask themselves daily. It can be hard determining what’s best for them, but you’ll likely feel guilty if you think you have euthanized them too early. 

Try not to get too caught up with your emotions about when to euthanize. Your vet will tell you when to start thinking about putting your dog down. However, sure signs that your dog will not return to its usual self are:

  • Their quality of life has completely vanished
  • Treatment is not helping
  • They are in much pain
  • They are not willing to eat or drink

Although it’s hard to make the final decision to euthanize, your dog knows you love them and will appreciate your strength in the end. 


Although many dog owners spend countless hours researching canine lymphoma and many sleepless nights worried about their furever friend, some common questions do ease their mind.

Which Dog Breeds Are Prone to Lymphoma?

While most dogs are prone to genetic health issues like hip and elbow dysplasia, other breeds are prone to developing lymphoma or other cancers. 

Larger dogs are prone to lymphoma due to their size’s genetic history, and environmental factors. Those are: Purebred Golden Retrievers, Bernese Mountain Dogs, Great Danes, Large Poodles, Rottweilers, Doberman Pinschers, Bullmastiffs, Boxers.

While lymphoma is not directly associated with these breeds alone, scientists are still unsure why genetic history has anything to do with cancer in dogs. 

Is There Treatment for Dogs with Lymphoma?

Treatment options are available to dogs diagnosed with lymphoma. However, treatment options vary depending on the stage and progression of your dog’s lymphoma. Treatment includes chemotherapy, surgery, and radiation.

What Is the Most Common Treatment?

The most common treatment option is chemotherapy. However, the side effects consist of vomiting, decreased appetite, and diarrhea. 

Is Surgery Or Radiation Recommended?

If the lymphoma exists in a specific spot on your dog, your vet may recommend surgery to prevent it from spreading. Radiation may cause skin irritation and itchiness; however, radiation therapy is a way to stop cancer from becoming aggressive and taking over. 

How Much Does Treatment Cost?

Unfortunately, lymphoma treatment is not a cheap process. You can expect to pay up to $2000 for the required tests for the diagnosis. 
After being diagnosed with lymphoma, you can expect to pay $300 to $10,000 for ongoing treatment.

Is the Pricy Treatment Effective?

Even with the costly figures for your dog, there is still a chance they may not return to a full quality of life. The high costs of the lymphoma process are perhaps why some people decide to go without treatment and euthanize their dog when their time has come. 

Is Lymphoma Painful for Dogs?

Even though lymphoma is the most common cancer for dogs, cancer itself is not painful. However, there may be some pain at the beginning of the process with treatment, but barely noticeable.

Do the Dogs Feel More Pain in the Late Stage?

The worst symptom for you and your dog is to have the freedom of life taken away because of lymphoma. Near the end of your dog’s life, they may feel more pain as cancer spreads to areas that disable your dog’s ability to move.

Bottom Line: Dog Lymphoma, When to Euthanize

Lymphoma is the most common cancer found in dogs. While any cancer diagnosis in your furry friend is hard, one question will remain through the entire process: When do I euthanize my dog if he has lymphoma? 

There is no cure or definitive answer for this question. The most appropriate time to put your dog down will be when you notice your dog is struggling to survive. Your vet will let you know when it’s time in most cases.

Whatever decision you choose, ensure that you do it with confidence and no regret.

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Picture of Sarah Alward | Doctor of Veterinary Medicine
Sarah Alward | Doctor of Veterinary Medicine
Our resident DVM helps review every article to ensure we always provide scientifically accurate, up-to-date information. She’s proud to help provide pet parents everywhere with the info they need to keep their pets safe, healthy, and comfortable.