Causes
Cancer of the lymphocytes. The cause is multifactorial. In cats, FeLV infection is a risk factor.
Diagnosis
Needle aspirate or biopsy of a lymph node or the mass, blood work, and imaging to assess how far it has spread.
Treatment
Chemotherapy is the main treatment and, in dogs, it is usually well tolerated, achieving long remissions with a good quality of life. The prognosis depends on the type and extent of the disease.
Prevention
Not preventable. In cats, vaccination against FeLV reduces one risk factor.

