Where are dogs lymph nodes?

As a dog owner, knowing where your dog’s lymph nodes are and what changes in them might mean can be one of the most practical skills you pick up. A quick feel during grooming or while cuddling can help you catch infections, dental problems, or more serious issues earlier. That early recognition often makes the difference between a simple clinic visit and a more complicated emergency. The guidance below is written from the viewpoint of someone who examines dogs regularly, with plain steps you can use at home and clear signs to share with your veterinarian.

Why understanding canine lymph nodes matters for every dog owner

Routine checks of lymph nodes matter because they are a common early warning system. Lymph nodes drain nearby tissues, so a swollen node often points to a nearby problem — a tooth infection, an ear infection, a wound — before other signs become obvious. In grooming, boarding, or kennel situations a quick comment to staff such as “his jaw node feels a bit larger than usual” gives caretakers and vets a useful head start. When communicating with your vet, the quality of information you can provide — timeline, speed of growth, whether the node is painful — helps direct whether tests or immediate care are needed. In short, knowing the basics reduces uncertainty and improves outcomes.

At-a-glance map: locating your dog’s major lymph nodes

Below are the common, superficial lymph nodes you can usually find on a typical dog:

• Mandibular: just under the jaw along the jawline, near where the lower jaw meets the throat.
• Prescapular (superficial cervical): in front of each shoulder blade at the base of the neck.
• Axillary: in the armpit area where the foreleg meets the chest.
• Inguinal: in the groin where the hind leg joins the body, and popliteal: behind the knee of each hind leg.

There are also deeper nodes, such as retropharyngeal and thoracic nodes, which sit inside the head and chest and are normally not palpable. If a deep node becomes enlarged, it is less likely you will feel it at home and more likely you will notice systemic signs first, such as fever or breathing changes.

How lymph nodes protect your dog — and why they sometimes swell

Lymph nodes act as filters and staging areas for the immune system. Fluid carrying cells and debris from tissues passes through nodes where immune cells can recognize and respond to foreign material. A node that feels larger may contain more immune cells, fluid, or debris because it is working to clear a local problem. When immune cells are activated there can also be increased blood flow and mild swelling, which is usually a sign the body is responding.

Each node tends to drain a predictable territory. For example, the mandibular nodes drain the mouth and nearby facial tissues, so dental disease or facial skin infections often cause enlargement there. The prescapular and axillary nodes collect drainage from the forelimb and chest wall, while inguinal nodes deal with the belly and hindlimb. Understanding these drainage areas makes it easier to link a swollen node to a likely source.

Common causes and factors behind lymph node changes

Nodes can change for several reasons and the context matters. Local infections such as infected teeth, scratches, ear infections, or skin abscesses are common causes of one or two swollen lymph nodes near the lesion. Systemic infections — bacterial, viral, or parasitic — may cause multiple nodes to be enlarged at once. Vaccinations or recent injections can cause temporary enlargement that often resolves in a few days to weeks. I typically see a small, soft enlargement after routine vaccines that settles without treatment.

Cancer is another important trigger. Lymph nodes can become enlarged because cancer cells have spread to them, or because the node itself contains a tumor. In those cases the node may change more slowly or may feel firmer and less mobile. Immune-mediated diseases can also alter nodes, though these are less common. Breed and age play a role: younger dogs often show more reactive nodes with infections, while older dogs are statistically more likely to develop cancers. Acute problems typically cause quick swelling and tenderness; chronic issues tend to produce steady growth over weeks to months.

Red flags to watch for: when swollen nodes become urgent

Not every swollen node is an emergency, but certain features raise concern. Rapid growth over a few days, or persistence beyond two to three weeks despite no clear cause, is a reason to contact your vet. Nodes that feel hard, fixed to surrounding tissue, irregular in shape, or extremely painful may suggest a more serious process. Systemic signs such as fever, weight loss, lack of appetite, marked lethargy, or multiple nodes enlarged across the body should prompt prompt veterinary evaluation. If the skin over a node breaks down or you see ulcers near the node, that also needs urgent assessment. I often tell owners that a single soft, slightly enlarged node without other signs can be watched for a short period, but any of the red flags above should shorten that watchful period to immediate veterinary attention.

If you find a lump: clear, practical actions owners can take

When you want to check your dog’s lymph nodes, follow a calm, consistent sequence so you don’t miss a location and so your notes are useful later. A simple tactile routine helps you compare left and right and to track changes over time:

1. Mandibular: with your dog standing or sitting, run your fingertips along the lower jaw just below the cheek; you should feel a small soft almond-shaped node on each side if palpable.
2. Prescapular: place your hands in front of each shoulder blade and feel for a soft oval under the muscle at the base of the neck.
3. Axillary: lift the forelimb slightly and feel into the armpit toward the chest wall; nodes here can be small and tucked under fur.
4. Inguinal: lift a hind leg and feel the crease between belly and thigh; inguinal nodes often feel like small beans if present.
5. Popliteal: with the hind leg relaxed, feel behind the knee for a small firm node in the hollow just above the back of the leg.

As you feel each node, note these characteristics: approximate size (measure with a small tape or ruler if you can), shape (round or elongated), consistency (soft, squishy, firm), mobility (does it slide under the skin or seem fixed), warmth compared with surrounding skin, and whether it elicits pain when you touch it. Photograph the area with a ruler in the frame and record the date and any related signs (recent cuts, dental issues, vaccines). If you see rapid enlargement, fever, or multiple nodes involved, call your veterinarian right away and report the timeline and your measurements.

Calm and controlled: handling your dog safely during checks

Keeping your dog calm makes the check safer and more reliable. Choose a quiet place with familiar bedding and minimal distractions. Work slowly, using gentle, steady pressure rather than digging or pinching. Offer small, tasty treats and praise — a few seconds of touch followed by a reward teaches your dog that checks are positive. For dogs who are wary, start with a short, very gentle touch and gradually increase time over several sessions. Read your dog’s body language: tucked tail, lip licking, stiffening, or growling are signs to stop and try again later or to seek help.

For large or anxious dogs, ask a calm helper to provide gentle, non-restrictive support — not forceful restraint — so your dog feels steadier. If your dog is painful or unusually fearful, a veterinary nurse or a behavior-savvy handler can demonstrate safe techniques. If you ever feel unsure or if the dog shows defensive aggression during checks, do not force the exam; arrange veterinary assistance where appropriate pain relief and safe handling are available.

Practical tools and supplies to make at-home exams easier

A few simple tools make your observations more reliable. A soft measuring tape or a small ruler helps you track size consistently. Your smartphone is useful for photos and short videos; include a date stamp or take a picture with a ruler beside the node so the vet can gauge scale. Soft, high-value treats and a non-slip mat help the dog stand steadily. Thin disposable gloves can be handy if there is a wound or drainage, and a towel can help steady an anxious dog without applying pressure to a suspicious area. These items keep the check tidy and make your notes more useful to the clinic.

Preparing for the vet: concise observations and notes to bring

When you call the clinic, a clear, concise report helps triage and care. Tell the clinician where the node is, when you first noticed it, whether it has changed quickly, whether the dog has a fever or other signs, and whether the dog has had recent vaccines or injuries. Mention any treatments you’ve already tried, such as topical cleansers or antibiotics prescribed previously, and send the photos you took. That information frequently directs the next steps — advice for home monitoring, scheduling a physical exam, or setting up tests such as fine-needle aspiration or blood work.

References and further reading

• Merck Veterinary Manual: “Lymphadenopathy in Dogs and Cats” — Merck & Co., Inc., Veterinary Manual Online
• Textbook of Veterinary Internal Medicine: “Approach to the Patient with Lymphadenomegaly” — Ettinger, Feldman & Côté, 8th edition
• American Veterinary Medical Association (AVMA): client information on “Recognizing Signs of Illness in Dogs” and guidance for when to seek veterinary care
• World Small Animal Veterinary Association (WSAVA): “Vaccination Guidelines” — notes on local and systemic post-vaccination reactions
• Small Animal Surgery and Physical Examination texts: chapters on regional lymphatic anatomy and clinical examination (veterinary clinical textbooks commonly used in practice)