Your vet checks your pet's lymph nodes at every exam -- but do you know why? The lymphatic system is your pet's internal security network, and swollen lymph nodes are its alarm bells.
The lymphatic system runs parallel to the circulatory system and serves as the body's immune highway -- transporting white blood cells, filtering pathogens, and draining excess fluid from tissues. Think of lymph nodes as security checkpoints. When something is wrong, they swell as they work overtime to fight the threat.
Swollen lymph nodes (lymphadenopathy) indicate the immune system is actively responding. Causes range from a local skin infection or tooth abscess, to systemic infection, immune-mediated disease, or cancer (lymphoma).
Submandibular nodes: Cup your pet's face and feel along the underside of the jaw. Normal nodes feel like small smooth firm peas. Swollen nodes feel larger -- sometimes grape-sized or bigger.
Popliteal nodes: Feel the back of the hind legs just above the knee. These are often the easiest to find.
Normal = small, smooth, moveable, non-painful. Abnormal = larger than usual, hard, fixed in place, or painful when touched.
Lymphoma is one of the most common cancers in both dogs and cats. In dogs it often presents as multiple lymph nodes swelling simultaneously -- sometimes dramatically, to golf-ball size. Dogs treated with chemotherapy have median survival of 12-14 months. Untreated: 4-6 weeks. Early detection matters enormously.
Make lymph node checks part of your monthly petting routine. Run your fingers along the jaw, shoulders, armpits, groin, and behind the knees. You are learning what normal feels like for your pet so that abnormal is immediately obvious.