Because lymphocytes are scattered through all organs, lymph cancer can occur in any organ. Lymphoma occurs commonly in both dogs and cats. Although most cancers occur in older animals this type of cancer can occur in young animals as well although less commonly than in the older animal. Certain breeds of dogs develop lymphoma more often than others. There are several forms of this cancer that require different diagnostic tests and respond differently to treatment.
Lymphoma occurs in several different forms, which result in different signs.
There is overlap across these forms and some animals may have mixtures of different forms. A cat with lymphoma may have an active infection with this virus or may have had an infection with the leukemia virus years ago and gotten rid of the virus. Feline leukemia virus can cause cancer to develop many years after the virus has been cleared from the body. Young cats with lymphoma are more likely to be positive for the feline leukemia virus than older cats with lymphoma. In addition to causing cancer this virus itself suppresses the immune system leading to infection and often causes anemia.