Lymphoma in Pets: The Most Common Cancer
Lymphoma is the most common cancer in dogs and cats. With treatment, many pets enjoy months to years of good quality life.
Lymphoma (lymphosarcoma) is a cancer of lymphocytes — white blood cells that are part of the immune system. It's the most frequently diagnosed cancer in dogs and cats, accounting for up to 20% of all canine cancers and 30% of feline cancers.
Key Points
- Lymphoma is the most common cancer in dogs and cats
- The multicentric form (enlarged lymph nodes) is most common in dogs
- Cats most often develop gastrointestinal or mediastinal lymphoma
- Chemotherapy is highly effective — 70-90% of dogs achieve remission
- Feline lymphoma is linked to FeLV and FIV in some cases
- With treatment, dogs live 12-18 months; cats 6-12 months on average
Types of Lymphoma
Multicentric lymphoma — enlarged lymph nodes throughout the body. Most common in dogs and highly responsive to chemotherapy. Gastrointestinal lymphoma — affects the stomach and intestines. Common in cats and may respond to prednisolone alone or chemotherapy. Mediastinal lymphoma — affects the chest and thymus. Seen in young FeLV-positive cats. Cutaneous lymphoma — affects the skin. Alimentary lymphoma — affects the intestinal tract.
Diagnosis
Physical exam reveals enlarged lymph nodes. Fine needle aspiration and cytology confirm the diagnosis. Biopsy provides definitive diagnosis and subtype classification. Blood tests, urinalysis, and imaging (X-rays, ultrasound) evaluate extent. Bone marrow biopsy assesses bone marrow involvement. Staging helps determine prognosis and treatment. Flow cytometry and immunohistochemistry classify the lymphoma type.
Treatment
Chemotherapy is the main treatment. Dogs typically receive CHOP protocol (cyclophosphamide, doxorubicin, vincristine, prednisone) — 70-90% achieve remission for 6-12 months. Cats may respond to prednisolone alone for GI lymphoma. More aggressive protocols extend survival. L-asparaginase, CCNU, and rescue protocols are available for relapsed cases. Side effects are usually mild — nausea and mild bone marrow suppression. Most pets maintain excellent quality of life during treatment.
When to See a Vet Immediately
- Your pet has enlarged lymph nodes
- There's unexplained weight loss and lethargy
- Your cat has gastrointestinal signs with no other cause
- There are new lumps or bumps throughout the body
- Previous FeLV/FIV positive status in cats
How RVC Can Help
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.