Lymphoma
What is it?
Lymphoma is a cancer of lymphocytes, a type of white blood cell. It most often appears as enlarged lymph nodes but can affect organs such as the spleen, liver, and intestines. It is one of the most common cancers in dogs.
What signs should I watch for?
Signs to watch for include firm, painless swellings under the jaw, in front of the shoulders, or behind the knees; lethargy or reduced appetite; weight loss; and increased thirst or breathing changes.
How is it diagnosed and treated?
A needle sample or biopsy of a lymph node confirms the diagnosis; blood work and imaging show how far it has spread. Chemotherapy is the main treatment, and dogs usually tolerate it much better than people do.
Can it be prevented, and what's the outlook?
- Lymphoma is rarely cured, but treatment often brings remission and good quality time.
- Report any new lumps promptly.
Reviewed by the Adler Veterinary Hospital veterinary team, October 2026.
Dogs; one of the most common canine cancers
Who's at risk:
Firm painless swellings at jaw, shoulders, or knees; lethargy
Main signs:
Schedule a visit soon
Urgency:
When to call a vet right away
- New firm swellings under the jaw, in front of the shoulders, or behind the knees
- Breathing changes
Not sure whether it can wait? Call us anyway. Our team can help you decide.
Source:
Related conditions
Bone Cancer
Splenic Tumors
Liver Tumors