Multicentric Lymphoma in Dogs

Multicentric lymphoma is a condition in which lymphocytes—white blood cells that normally patrol the body as part of the immune system—begin to multiply in an uncontrolled way within the lymph nodes. These nodes, which sit at junctions throughout the body, become visibly enlarged. In dogs, this form of lymphoma tends to affect multiple node groups at once, which is why it carries the name multicentric. Owners often first notice firm, painless swellings under the jaw, in front of the shoulders, or behind the knees. The dog may otherwise seem well in the early stages, or there may be quieter signs such as reduced appetite, weight loss, or a general sense that energy has dipped. Because the nodes themselves are not usually tender, the swelling can be present for some time before it prompts concern. This page explores what these swellings may signal, what is happening within the lymphatic system, how the condition is investigated through examination and laboratory work, and the range of approaches that exist once a picture has formed. The goal is orientation, not instruction—understanding the landscape so that conversations with your veterinary team can be as clear and grounded as possible.