Lymphoma

A cancer of lymphocytes; multiple anatomic forms (multicentric, alimentary, mediastinal, cutaneous).

What is Lymphoma?

Lymphoma is one of the most common cancers in dogs. The multicentric form (enlarged lymph nodes) accounts for about 80% of cases and often presents as painless, firm swellings under the jaw, in front of the shoulders, or behind the knees. Other forms affect the GI tract, chest cavity, skin, or a single organ.

Common signs and symptoms

Signs vary between dogs and can be subtle at first. Watch for the following, especially if several appear together or persist for more than a few days:

  • Painless firm swellings at lymph node sites
  • Reduced appetite and weight loss
  • Increased thirst and urination
  • Laboured breathing (mediastinal form)
  • Chronic diarrhoea (alimentary form)
  • Skin nodules or plaques (cutaneous form)

Risk factors

Certain dogs are more predisposed. Understanding risk helps you screen earlier and act sooner.

  • Golden Retriever, Boxer, Bullmastiff, Basset Hound, Saint Bernard
  • Middle-aged to senior dogs

When to see a vet

Use this as general triage guidance, not a substitute for veterinary advice.

  • Book a routine appointment if: any persistent firm lump at a lymph node site — same-day cytology usually gives an answer.
  • Seek urgent care if: breathing difficulty, sudden collapse, or severe dehydration.

Diagnosis and management

Diagnosis is via aspirate or biopsy, with immunophenotyping (B-cell vs T-cell) guiding prognosis. Multi-agent chemotherapy protocols (CHOP) achieve remission in most B-cell cases, with median survival around a year. Prednisone alone is a lower-cost palliative option (median a few months). New targeted therapies are expanding options.

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