Where Are a Dog's Lymph Nodes? How to Check Them at Home

Dogs have lymph nodes throughout the body, but only three sets can be reliably felt from the outside in a healthy dog: the mandibular nodes under the jaw, the superficial cervical or prescapular nodes just in front of each shoulder, and the popliteal nodes behind each knee (Worden et al., 2023).

Two more, the axillary in the armpit and the superficial inguinal in the groin, are usually not palpable when normal. That is worth knowing rather than finding discouraging. If you can suddenly feel a node in your dog's armpit, the fact that you can feel it at all is itself the finding.

The most useful thing a home check gives you is a baseline. Knowing what your own dog's nodes feel like when they are well is what allows you to notice change later, and change is what matters. A single measurement in isolation tells you very little.

Two limits are worth being clear about before you start. Enlarged nodes are not proof of cancer, since infection and inflammation enlarge them too. And normal-sized nodes do not rule cancer out. Current guidelines state plainly that evaluating lymph nodes by palpation and size is not always a reliable indicator of metastasis, and that normal-sized nodes may still harbour cancer (Christensen et al., 2026). Only a needle sample can answer that question.

Key points

• Three sets are reliably palpable in a healthy dog: mandibular, superficial cervical (prescapular), and popliteal (Worden et al., 2023).
• Normal nodes are small, usually under a centimetre, soft, non-painful, and slide easily under your fingers.
• The single most common mistake is confusing the mandibular lymph node with the mandibular salivary gland, which sits in almost the same place and is normally larger.
• In multicentric lymphoma, the most common form in dogs, nodes are typically enlarged across multiple sites, firm, and not painful, and many dogs feel completely well at that point (Merck Veterinary Manual, 2025).
• Nodes 3 to 10 times normal size are typical in lymphoma, and they are initially freely movable but become fixed as disease progresses (Merck Veterinary Manual, 2025).
• Normal-sized nodes can still contain cancer, and enlarged nodes are often reactive rather than malignant. Sampling settles it, palpation does not (Christensen et al., 2026).
• Absence of enlarged peripheral nodes does not rule out lymphoma, because some forms involve only internal sites.
• Weekly is plenty. Checking several times a day tells you nothing and costs you a great deal.

Detailed explanation

Why this matters in cancer

Lymph nodes are filters. Fluid drains from tissues through them, and immune cells inside sample what passes through. That filtering role is exactly why they matter in cancer, because cancer cells travelling away from a primary tumour often lodge in the first node downstream.

For dogs with a known tumour, the regional node is where spread tends to show up first. For dogs without a diagnosis, generalised enlargement across several sites is one of the classic presentations of lymphoma, which accounts for the majority of cases seen as nonpainful, generalised peripheral lymphadenopathy (Merck Veterinary Manual, 2025).

The other reason to learn this is that owners find these things. Most dogs with multicentric lymphoma are presented because someone noticed lumps under the chin, not because of illness. Many of those dogs feel entirely well at diagnosis.

The three you can reliably feel

Mandibular nodes, under the jaw. These sit beneath the angle of the lower jaw, toward the front, on both sides. Most dogs have two to four in this area on each side.

To check them, stand or sit with your dog facing away from you, so they are not trying to lick your hands. Run the pads of your fingers along the underside of the jaw on both sides at once, starting just behind the chin and working back toward where the jaw meets the neck. Use light pressure. You are feeling for small, smooth, mobile structures rather than pressing hard into tissue.

Superficial cervical nodes, in front of the shoulders. Also called prescapular nodes, these sit just in front of the shoulder joint in the tissue at the base of the neck (Worden et al., 2023). They are easiest to feel with your dog standing.

Find the point of the shoulder with your fingertips, then move slightly forward into the softer tissue in front of it and press gently but progressively deeper. These sit a little deeper than the mandibular nodes, so they take more patience to find the first time. Once you have found them once, they are easy to find again.

Popliteal nodes, behind the knees. These are in the fat pocket at the back of the hind leg, directly behind the stifle, which is the joint that corresponds to our knee. This is the largest node in the hind limb.

With your dog standing, cup a hind leg from behind, placing your thumb on one side and fingers on the other at the level of the back of the knee joint. Roll your fingers gently. Many owners find these the easiest of all to identify because they sit in soft tissue with little else nearby to confuse them.

The two you usually cannot feel, and why that is useful

Axillary nodes, in the armpit. These sit deep, and in a normal dog you generally will not find them (Worden et al., 2023). If you want to try, gently lift the front leg slightly outward and press up into the armpit.

Superficial inguinal nodes, in the groin. In male dogs these sit in the lower abdomen forward of the hind legs, and in females they sit near the last mammary gland. They are sometimes palpable in normal male dogs and large dogs, but often not.

Here is the useful part. Because these are not normally palpable, feeling one at all is meaningful information. If you can suddenly find a firm lump in your dog's armpit or groin where you never could before, that is worth a call rather than a shrug.

The mistake almost everyone makes

The mandibular salivary gland sits in nearly the same region as the mandibular lymph node, and it is normally the larger of the two. Owners find it, panic, and arrive at the clinic convinced their dog has lymphoma.

Two things help distinguish them. The lymph nodes are usually more mobile, sliding freely under your fingers, while the salivary gland feels more anchored. And the nodes usually sit further forward, toward the front of the jaw, with the salivary gland further back.

If you are not sure, the best solution is not more internet reading. Ask your veterinarian to place your fingers on your dog's normal nodes at the next appointment. Thirty seconds of guided hands-on beats any written description, including this one, and most veterinarians are glad to do it.

What normal feels like

Small. In most dogs, normal nodes are under a centimetre, and often noticeably smaller than that. Size varies with the size of the dog.

Soft, rather than hard or rubbery. Smooth, not lumpy. Mobile, sliding under your fingers rather than feeling stuck to what is beneath. And not painful, meaning your dog should show no reaction beyond ordinary tolerance of being handled.

Both sides should feel roughly the same. Symmetry is a useful reference point that costs nothing to check.

What abnormal feels like

Size. In lymphoma, peripheral nodes are commonly 3 to 10 times their normal size (Merck Veterinary Manual, 2025). That is a dramatic change, not a subtle one. Owners often describe the change happening over days to a couple of weeks.

Texture. Firm rather than soft.

Pain, or its absence. This is counterintuitive and worth reading twice. Cancerous nodes are characteristically not painful, whereas nodes enlarged by infection often are. A node that is large but does not seem to bother your dog is not reassuring. If anything, it is the opposite.

Mobility. In lymphoma, affected nodes are initially freely movable but become fixed as the disease progresses and can begin to compress surrounding structures (Merck Veterinary Manual, 2025). A node that feels stuck to the tissue beneath is a more concerning finding than one that slides.

Distribution. One enlarged node near a known tumour raises the question of regional spread. Several enlarged nodes across different parts of the body raises the question of lymphoma. Both need a call, but they are different questions.

The two things a home check cannot tell you

It cannot rule cancer out. This is the correction that matters most. Nodes may be enlarged because of metastatic disease or because of infection and inflammation, and normal-sized nodes may still contain metastatic disease. Determining which requires a fine needle aspirate or a biopsy, not palpation (Christensen et al., 2026).

There is a second version of this. Absence of enlarged peripheral nodes does not rule out lymphoma, because some dogs have disease confined to internal sites such as the liver, spleen, or gut that no home check will ever detect.

It cannot tell you what an enlarged node means. Generalised lymphadenopathy has a long list of causes besides cancer, including bacterial, fungal, viral, and parasitic infection. Fungal disease in particular is regionally distributed, so where your dog has lived and travelled genuinely matters and is worth mentioning.

A needle sample of a lymph node is quick, usually needs no sedation, and results often come back within a couple of days. It is one of the least burdensome tests in veterinary medicine, and it answers the question that palpation cannot.

How often to check, and how to keep this in proportion

Once a week is plenty for most dogs. For a dog in remission from lymphoma, your oncologist may suggest something specific, so follow that instead.

Pick a fixed moment so it becomes routine rather than an event. During an evening settle on the sofa works well. Keep it brief, unhurried, and pleasant, because a dog who learns that hands under the jaw predict something tense will start avoiding it.

Now the part that matters for you rather than your dog. It is entirely possible to check lymph nodes four times a day, convince yourself something has changed, and lose whole evenings to it. Nodes do not change measurably over hours, so frequent checking generates anxiety without generating information. If you notice yourself checking compulsively, that is worth naming to someone, and it is a good thing to raise with your veterinary team, who see it often and will not think less of you.

Writing down what you find, with a date, helps more than repeated checking. Memory is unreliable about gradual change, and a simple note turns "I think it might be bigger" into something a clinician can actually use.

What to do when you find something

Do not spend the evening searching image results and comparing them to your dog. Call the practice and describe it: which site, one side or both, roughly what size, firm or soft, painful or not, mobile or fixed, and when you first noticed it.

Then leave it alone. Repeatedly squeezing a node will not tell you more, and for masses that might be mast cell tumours, handling can provoke histamine release. Gentle handling is the rule when you are not sure what you are feeling.

When to contact a veterinarian

Seek same-day or emergency care if your dog has:

• Enlarged nodes under the jaw or in the neck alongside difficulty breathing, noisy breathing, or facial swelling
• Sudden enlargement across multiple sites accompanied by lethargy, collapse, or refusal to eat
• Any enlarged node alongside pale gums, weakness, or laboured breathing

Call your veterinary practice within a day or two if you find:

• Enlarged nodes at more than one location
• A node that has clearly grown over days to weeks
• A node that feels firm, fixed in place, or noticeably different from the same node on the other side
• Any palpable node in the armpit or groin where you could not feel one before
• An enlarged node near a tumour your dog is already known to have
• Enlarged nodes alongside increased drinking and urinating, which can accompany lymphoma-related high blood calcium

Raise it at the next appointment if:

• You are unsure whether what you are feeling is a lymph node or a salivary gland, and your dog is otherwise well. Ask to be shown. This is a good use of an appointment, not a waste of one.

Questions to ask your veterinarian

• Can you show me where my dog's normal lymph nodes are, so I know what I am feeling for?
• Which nodes should I be watching most closely, given my dog's cancer type and location?
• How often would you like me to check, and how should I record what I find?
• If I find a change, should I call or wait for the next appointment?
• Can this node be aspirated, and how quickly would we get results?
• Could this enlargement be infection rather than cancer, and how would we tell?
• Does my dog's regional node need sampling as part of staging, even if it feels normal?
• Is there anything about handling my dog's masses that I should be careful about?

This article is for educational purposes only and is not a substitute for veterinary care. Checking lymph nodes at home does not replace veterinary examination, and it cannot confirm or rule out cancer. Only sampling can do that. If you find a change, or if you are unsure what you are feeling, contact your veterinarian.

References

Christensen, J., Johnson, K., Ettinger, S., Garrett, L., Gordon, I., Ireifej, S., Love, A., & Wisecup, M. (2026). AAHA oncology guidelines for dogs and cats. Journal of the American Animal Hospital Association, 62(1), 1–37. https://doi.org/10.5326/JAAHA-MS-7549

Merck Veterinary Manual. (2025). Lymphoma in dogs. https://www.merckvetmanual.com/circulatory-system/lymphoma-in-dogs/lymphoma-in-dogs

Worden, N. J., Bertran, J., Watt, M. M., Reynolds, P. S., de Mello Souza, C. H., Maxwell, E. A., Adin, C. A., Ham, K., & Regier, P. J. (2023). Superficial anatomic landmarks can be used to triangulate the location of canine peripheral lymphocentrums: Superficial cervical, axillary, and superficial inguinal. Journal of the American Veterinary Medical Association, 261(4), 490–499. https://doi.org/10.2460/javma.22.11.0518