Dog Lymph Nodes: Lymphadenopathy, Lymphadenitis and Cancer

Veterinarian Examining Dog
Wyatt Robinson
Written by Wyatt Robinson

Dogs, just like humans, can suffer from different health conditions. While some are mild and can be treated at home, others can be life-threatening. This is why pet owners need to be aware of the signs that can indicate that something is not right with their pet. The more you know about its traits, strengths and weaknesses, the better you can look after it. This article aims to approach dog lymph nodes because they play a major role in how the immune system works. Furthermore, this is where the white cells are stored, thus any sign of inflammation needs to be kept under control.

Pet owners who find a lump or a bump that appears out of the blue on their dog usually take it as an injury.

However, if it does not disappear after several days or it keeps growing, it is generally the sign of something more serious. There are various causes that can lead to this illness, thus it is important to be able to identify them from an early stage. This is why it is mandatory to take your pet to the veterinarian in order to receive further attention. Swollen lymph nodes usually indicate an infection. As a result, it is essential to localize it and stop it before it spreads throughout the body. In the following lines, you will find further details about this problem.

Location of lymph nodes

Enlarged lymph nodes are the first indicator that something is not right with your pet. However, in order to be able to spot the initial changes it is important to know the areas that need to be checked. In most cases, a lump found in these specific places on the skin can indicate even cancer. At the same time, it is important to understand that early detection means higher chances to get the right treatment and to enjoy positive result.

Location of nodes

This means that you need to accustom your pet with regular massages. Gently move your fingers along its skin, and make sure you pay extra attention in the following areas, as this is where the bumps or lumps can occur:

  1. underneath the muzzle;
  2. the back of the head;
  3. the armpits;
  4. the inguinal area;
  5. the back legs.


Lymphadenopathy is a condition that indicates swollen lymph nodes in dogs due to an infection. The nodes can be detected easily, as they can be felt at touch. Though in most cases the dog starts to display certain symptoms that can indicate this illness, there are situation when it feels absolutely fine. The bumps are usually located around the shoulder or just beneath the jaw.

Sometimes, the whole back leg or the joint can get swollen. Nausea is also very common, and this leads to lack of appetite. Furthermore, your pet can vomit almost immediately after it finishes its food. If the nodes located in the jaw area become very prominent, they can cause breathing difficulties and trouble while swallowing.


There are various causes that lead to this illness. The most important trigger is an infection in the organism. However, there are also other agents that can trigger it. In order to be able to take the right decision and to identify the problem at an early stage it is mandatory to be aware of the following situations:

  • an infection in the organism that forces the body to produce white blood cells in excess. In this case, the lymph nodes are not infected;
  • the lymph nodes get infected in the first place, or an infection that is already in the organism affects them;
  • an infection caused by external agents that attack the skin, bones, lungs and brain, generally caused by fungi, hay, or plants;
  • a bacterial infection transmitted by flies, fleas, or rodents;
  • a bacterial infection transmitted during breeding, or through the respiratory system;
  • a bacterial infection that affects the respiratory system;
  • a mycrobacterial infection transmitted through water;
  • allergies can make the body produce more cells and the first to respond are the lymph nodes that are situated close to the reaction;
  • an immune-mediate disease that causes the organism to overreact to certain external factors;
  • uncontrollable multiplication of white blood cells as a response to allergens or to parasitic agents;
  • leukemia;
  • canine hyperosinophilic syndrome.

In order to receive the correct diagnosis it is mandatory to take your pet to the veterinarian as soon as you notice any bumps. The situation is even more urgent if the dog starts to behave in a strange manner. Lymph nodes cancer in dogs is a reality, thus immediate treatment is needed. The best way to find out the cause of the swollen nodes is to perform certain test, like blood profile, electrolyte panel, a complete blood count and a blood smear.

In most cases, the veterinarian will also take some liquid samples right from the nodes for detailed microscopic examination. At this point, you need to be able to give the health history of your pet, and also include eventual symptoms and maybe incidents that can be associated with this disease. This is extremely important because it can point out the organs that are affected and cause the enlargement of the lymph nodes.

Radiograph imaging

If the veterinarian has any doubts regarding the root of the problem, some other additional tests may be needed. The most common ones are the ultrasound and radiograph imaging because they provide a better perspective on the affected lymph nodes. After the veterinarian has all the results he can prescribe the right treatment that can help the dog feel better. The medication depends on the cause, thus there is no general rule in this case.

It is also important to know that there are certain infections that can be transmitted to the owners. If you find out that your pet can be contagious, it is mandatory to make some tests yourself and ask the veterinarian which would be the optimal prevention options. During the treatment period, it is a good idea to limit contact as much as possible, and most important to keep the dog away from other family members, and especially from kids and elderly.


Lymphadenitis occurs when the white blood cells migrate actively. It is important to know that there are different types of such cells that can lead to this illness. To be more exact, there are the cells accountable with digesting and engulfing pathogens, the ones responsible with the immune system, but also neutrophils that are the most abundant in the body. As the lymph nodes have filtration functions, they are directly exposed to toxic agents.

This condition occurs when an infectious agent manages to reach the lymph nodes. The body then reacts and starts to produce white blood cells in excess. Lymphadenitis is generally caused by mycrobacteria and fungi, known to be the pathogens that cause the most serious diseases in the animal kingdom.

Fungal infection

The good news is that this illness is not transmitted genetically. However, pet owners need to know that puppies are more susceptible to it than adult dogs. The major problem is the immune system that is not fully developed.

As a result, infections can occur easily, especially if the dog gets in direct contact with contaminated water. This is why it is recommended to ensure a clean and safe environment for the little one, in order to help it develop normally. Furthermore, food is also important, and it is mandatory to put emphasis on ingredients that encourage an optimal development of the immune system.

Lymphadenitis is easy to observe because it makes the lymph nodes enlarge really bad and they can be noticed even by a person who knows nothing about veterinary medicine. However, these bums must not be approached with indifference, especially if they are painful when you touch them. Other symptoms associated that can point out that your pet is not feeling all right are fever, lack of appetite (it may also refuse its favorite treats), and in some cases you can actually see that the infected area displays visible signs.

If the cause is bacterial, the nodes can develop abscesses that can start to drain at the exterior. If this illness is not treated immediately it can develop complications and can even extend to the surrounding organs. This health problem is caused by several factors, as it can be seen in the table below:

— pathogenic species are known to cause this lymph nodes infection;- tularemia affects directly the lymph nodes, causing lymphadenitis. — in case of a fungi infection, lymphadenitis becomes a manifestation of the disease;- not all fungal agents cause this inflammation of the lymph nodes. — most viral infection cause the inflammation of the lymph nodes;- the most affected area is the abdomen. — protozoa can cause lymph nodes infection, but there is no general rule;- there are also certain links between lymphadenitis and pulmonary disease. — a compromised immune system is susceptible to infections, and as a result, lymphadenitis can occur.

In order to receive an accurate diagnosis you need to take your dog to the veterinarian as soon as possible. You will be also asked to present its health history in order to find a cause that leads to the symptoms the pet displays.

For more accurate results, the vet will have to examine the affected area and see whether it is the result of the inflammation of the lymph nodes or a tumor. It is very important to find the cause or causes that made this to happen. This is why it is extremely important to analyze your dog’s behavior daily so you can notice eventual changes. All details count in such a situation.

In order to receive an accurate and correct diagnosis the veterinarian will recommend several tests. The first ones that will be taken are the urinalysis and complete blood count. They will indicate if the illness is caused by bacteria or fungi. In case the swollen lymph nodes are located in the abdomen or chest area, an ultrasound imaging and X-ray will also be required for more accurate results. It is also extremely important to take liquid samples from the inflamed area, thus the veterinarian will perform a fine-needle aspiration to determine the composition.

Canine Lymph Node Locations

As lymphadenitis is a lesion, there is no fix treatment that can cure it. To be more exact, the therapeutic recommendations can differ from a patient to another. Once the characteristics of the inflammation are established, the veterinarian can prescribe the adequate treatment. You also need to know that it depends directly on the results of the collected liquid. In most cases, this illness is treated with antibiotics.

However, this is no general rule, so you must not be concerned if the veterinarian comes with something different. It is mandatory to follow the exact specifications of the vet. Furthermore, you will have to attend regular check-ups to make sure that the infection was eliminated completely. Just like in the case of Lymphadenopathy, some organism can be transmitted to humans.

As a result, you need to ask for guidelines to protect yourself and the family, but also eventual pets. In this kind of situation, it is extremely important to remain calm. The treatment will make your dog feel better, and with a bit of care, everything will get back to normal in no time.

Lymph nodes and cancer

Unfortunately, the inflammation of the lymph nodes can also be an indicator of something more serious. Though cancer sounds like a terrible illness, if it is approached in a correct manner and identified at an early stage it can be removed from the organism. The first things that should take you directly to the vet with no delay are large swellings in the areas where the lymph nodes are located.

Just like in the two examples presented above, the diagnosis will be revealed based on a fine needle aspiration. This procedure does not take long and the results are 100% accurate. The test results will prove whether there are or not cancerous cells in the liquid.

Unlike lymphadenopathy and lymphadenitis, in case of lymph nodes cancer, the initial problem starts in the circulation system. As a result, surgical removal is ineffective. It is also true that it is very hard to cure, considering that the fluid can easily spread throughout the body. This is why it is extremely important to identify this illness at an early stage, to be able to receive the right treatment.

When lymphosarcoma occurs, the healthy cells in the lymphatic system become cancerous and they circulate throughout the body just like the normal ones do. Their mobility makes them impossible to locate in a single place. When the number of these cells starts to increase they cause swellings. This is when you notice that the lymph nodes start to enlarge.

Cancer signs in dogs

The veterinarian is the most entitled to come with an adequate treatment. In order to get the desired results you must follow it accordingly. Besides the medication, there are some other things you can do in order to ease the pain and help the organism fight the cancerous cells. Love and care are mandatory, and you can also consider including the following steps in your daily routine:

  • Change its diet completely and start cooking meals that can improve the immune system and strengthens its organism;
  • Chemotherapy, though it has some unpleasant effects, it is the best way to fight this illness. It is also important to know that nowadays drugs come with minimal side-effects for the pet. An oncologist can tell you more about this option;
  • Look for healthy supplements that can give your dog strength. Just make sure that they are made of healthy ingredients. In this case, it is recommended to ask the veterinarian which brand is the best;
  • You can ask the veterinarian about the herbs that can help the organism fight cancer and include them in the daily diet;
  • Make sure that you pet faces no stressful situations and assure it a cozy place to rest all day. You can also encourage it and try to spend as much time as you can with it;
  • Gentle massages can also help the dog feel better. Just make sure you do not put too much pressure on the affected areas;
  • In some cases, acupuncture can also help. Ask your veterinarian as he is the most entitled to decide whether it is appropriate for your dog;
  • Make sure your pet gets at least 8 or 9 hours of sleep each night.


Lymph nodes inflammation is an illness that can affect the dog’s organism in various ways. While in some situations it can be treated with the right medicines, in others it can turn out to be life-threatening. This is why it is recommended to keep a close eye on the exposed areas in order to observe eventual swellings.

Balanced diet plan

It is extremely important to ask for professional advice in order to determine the cause and establish an adequate treatment. As in some cases the lymph nodes can become painful, it is important to assure a comfortable place for the dog to rest. Also remember, that a balanced and healthy diet can strengthen the immune system and this helps your pet fight any disease more efficiently.

About the author
Wyatt Robinson
Wyatt Robinson

Wyatt Robinson had a great 25-years career as a veterinarian in United Kingdom. He used to be a member of British Veterinary Association and worked in 3 pet hospitals in London and Manchester. He is shining when he sees his pets healthy and full of energy and it is his duty to help other dog owners to keep their best friends full of life.

  • Charlotte Kingston

    My sisters 10 year old Jack Russel is in terrible pain. His tonsils are swollen and he has lymph nodes. His energy is so low although he is eating a bit. You can tell however that he is uncomfortable and keeps pacing about. His face is also swollen, poor dear! The vet gave him an antibiotic shot and pain killer meds. It’s not cancer as the vet said because of the sudden onset. Probably is tonsillitis. Has anyone had this happen to them before? I didn’t think dogs can have tonsillitis!

    • Tonsillitis is a very painful infection because it is really uncomfortable and will require immediate attention. Due to the sudden onset, the type of infection your dog had is called Acute Tonsillitis. There is another type of tonsillitis which lasts much longer, and it is called Chronic Tonsillitis.

  • Lorrie Simmons

    My son’s dog suddenly developed lymph nodes so she was taken to the vet. The doctor was leaning towards cancer, but still have to run some tests. The dog looked ok, though. There’s no decrease in appetite or weight loss. Could it be just infection? Anyone with similar experience?

    • It can be infection, and the tests being conducted by the veterinarian will help confirm the diagnosis. Let us hope for the best that this is not as serious as cancer. For the meantime, you should observe your dog’s behavior for any noticeable changes.

  • Donna

    My female pitbull has decrease in weight loss very heavy breathing,swollen lymph nodes loss of appetite,sluggish,difficulties eating,lumps(dimesize or smaller)balding throughout body.Not financially able to test for cancer or determine whether it’s an infection,virus,or cancer.Please shout out references or suggestions,I love my dog as if it were my child but because your poor isn’t a reason for death

    • Wyatt Robinson

      You can check your region for dog centers that offer free evaluation for its condition. With all the considerations you have raised, it is best for your dog to be seen first. Let us know which region/state you are in and we might find a center that can help her.

  • G Thomas

    My dog had swelling in his jaw area on one side. I took him to the vet about 4-5 months ago. It was a swollen lymph node. Node on other side of jaw area started swelling shortly after the one side. Other nodes started enlarging also (shoulder, back leg area). Prior to other nodes swelling, vet took fluid sample out of first swollen node, lab said no cancer. Vet took shallow biopsy from first swollen node, lab said no cancer, but wanted a deeper sample. Vet did not want to go deeper and I did not want him to either. Dog was put on Prednisone 20mg twice a day along with antibiotic (don’t recall which antibiotic). The dog looked back to normal after about 3-4 weeks. Vet took him off antibiotics. Dogs condition stayed the same, looked great. After being off antibiotics for about 3 weeks the vet cut the Prednisone dosage back. The swelling all came back after cutting the dosage back (gradually) to 7.5mg once a day. Took him back to the vet because of the swelling coming back and also because I thought he was having breathing difficulty. The dog is now on 10mg Prednisone twice a day. It has helped him be able to breathe normally, but the swelling in his jaw area is not going down. I think other nodes may have slight swelling, but the worst part is his jaw area, very enlarged (looks like a chipmunk). Even though lab results came back no cancer, the vet is convinced it is cancer. He was convinced it was cancer early on, and gave him about 2 months left to live. Almost 5 months later, he is still with me. I do not want to lose my buddy, he is not even 8 years old yet. The dog was a stray that I took in when he was a puppy. He is some sort of pit bull mix and weighs about 65 pounds. He seems normal, except for the swelling. No loss of appetite, no vomiting, no diarrhea. I am not convinced it is cancer, but what else could it be. Any help greatly appreciated. Thank-you.

    • Wyatt Robinson

      First of all, thank you for visiting Dogsaholic. We have a lot of things to discuss about your dog’s situation. First, have you considered taking a second opinion about your dog’s condition? While I do believe that this is not cancer, it might be an infection that compromises your dog’s breathing capacity and ability.

      The prednisone management is helpful, but this is not a curative management and its effectiveness can only work up to a certain extent. What is important for now is that you managed to critically observe your dog for any changes in behaviour and appetite, because if there is an obvious change in its temperament or eating habits, holistic changes and problems will start from there.

      Another remarkable feat that you’re dog has accomplished is to successfully outlive its preliminary prognosis and it warms my heart that he is still fighting and still surviving. So for now, what I would recommend is a second opinion or if possible, a routine radiographic run like CT scan to have a deeper scan and hopefully find what the problem is.

      • G Thomas

        Thank-you so much for your reply. The dog has taken a turn for the worse. I have an appointment Monday at a local university’s animal hospital. Hopefully they can save him. I think my vet misdiagnosed the problem. He took him off the prednisone too rapidly (in my opinion). He is back on 20mg prednisone twice a day. When I took him back he was having trouble breathing due to swelling. His breathing is good now with the prednisone, it is other things that are a problem. He just stopped eating today and can not lift his back end up. I have been carrying him outside for the last 2 days to spend time outside. I called the university Friday, they did not have an appointment available until Monday. It is going to be a long weekend for us both. Someone told me the vet should have done a PARR test. I don’t know if that was done or not because nothing was explained to me in much of any detail. I think I will be looking for another vet for my other dogs (and this one if he makes it through).

        • Wyatt Robinson

          Prednisone should be tapered and not weaned off in an instant because the dog’s body can negatively react from its absence. I hope we can ultimately determine the problem because not only it is stressful for the dog, but primarily for you as a pet parent. Obtaining a second opinion from another vet is always a good move, because vets vary in impression, and if you have a feeling that you are dealing with something more serious, it is a sound action to get another opinion to make sure that the intervention being given to your dog is as accurate and effective as possible.

  • Scar Stigr

    Post infection how long til nodes become normal size?

    • Wyatt Robinson

      This varies depending on the severity of the infection. Some only take few days, while others take almost an entire month. Age, overall vigor, and response from an existing medical management are factors that affect the speed of post-infection recovery and return of the nodes to normal size.

  • Tina Hurst

    My dog belches when I massage his lymph node sites which appear to continually bother him. He also experiences excessive panting, exercise intolerance, staggering, disorientation, his nose is permanently warm and dry but also nasal discharge, lay still on his side all the time. His anxiety and fear levels are constantly high. His bloods have come back normal. I would appreciate any advise as I’m extremely worried as he appears to be in distress and I’m not getting any answers fast.

  • Tina Hurst

    My dog belches when I massage his lymph node sites which appear to continually bother him. He also experiences excessive panting, exercise intolerance, staggering, disorientation, his nose is permanently warm and dry but also nasal discharge, lay still on his side all the time. HIs anxiety and fear levels are constantly high. His bloods have come back normal. I would appreciate any advise as I’m extremely worried as he appears to be in distress and I’m not getting any answers fast.

    • Wyatt Robinson

      It appears to be a case of agitation and distress. I would recommend refraining from the massage for the time being to allow the lymph nodes to function as they normally do. Has your veterinarian recommended any calming or anxiolytic agents for the distress?

  • Lora DeVore

    My dog Evie started out with swollen lymph nodes under the jaw back in nov 2016. We took her to vet and at the time they said could be her teeth causing infection or lymphoma. We had the teeth cleaned , extractions as needed and she was on antibiotics for a month or so. She also had needle aspiration of the lymph nodes which came back inconclusive. They wanted to cut her and take out part of the lymph node but I said no. They thought she had cancer and I seen no point in putting her though all that if it was because they were giving her 6 to 8 weeks to live. Fast foward to mid May 2017 and shes been fine up until then although lymph nodes under jaw still swollen. No medications all that time. She began to get larger under the jaw and was having issues breathing. I took her back to vet and they put her on steroids for 2 weeks. Didnt really seem to help much. Took her back and they doubled up on her dosage of steroids and now lymph nodes are shrinking some and she is much more comfortable and breathing normally. She is not sick or nausea. She eats well. She is a bit low energy but she always was. So what Im asking is can this be something else besides cancer that they are missing ? I mean the vet herself told me that her own dog had lymphoma and she got it chemo and it only lasted 10 months. We are on 7 months with no treatments. She says we’re living on borrowed time and still thinks its cancer? Is there anything I can do ??

    • Wyatt Robinson

      Have you considered having a second opinion? There are a lot of considerations on the information that you have shared. It might be cancer but this cannot be a definite diagnosis until a biopsy (which is considered as a gold standard to identify cancer). If there is no significant change in your dog’s health based on the current medical management, something needs to be done further.

  • Elmer Flock

    What was the outcome for your dog?