Symptoms of canine lymphoma include unusually large lymph nodes that feel hard and rubbery, swelling in the face, swelling in the legs, lethargy, lack of appetite and weight loss, according to Purdue University College of Veterinary Medicine. Dogs may also be extra thirsty and require more water.
There are several types of lymphoma in dogs, including multicentric lymphoma, cutaneous lymphoma, gastrointestinal lymphoma and mediastinal lymphoma. Cutaneous lymphoma usually starts out as red, flaky and itchy patches of skin on the dog, while mediastinal lymphoma usually means that the dog cannot breathe properly, reports Purdue University College of Veterinary Medicine. To diagnose all types of lymphoma, a biopsy is needed as well as staging tests to determine how widespread the disease is within the dog's body. Blood tests and a urinalysis are also recommended, according to PetMD.