What type of cancer is frequently diagnosed in older cats?

Lymphoma is frequently diagnosed in older cats due to its association with feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), both of which are more prevalent in older cat populations. This type of cancer arises from the lymphatic system, affecting lymphocytes and can present in various forms, including multicentric, gastrointestinal, and mediastinal lymphoma. The immune system typically has a natural decline with age, making older cats more susceptible to infections and cancers like lymphoma.

In contrast, melanoma, osteosarcoma, and fibrosarcoma are not as commonly diagnosed in older cats when compared to lymphoma. Osteosarcoma is primarily a disease of younger animals, particularly large-breed dogs. Melanoma often occurs in older dogs and can be aggressive, but it is rarer in felines. Fibrosarcoma can occur in cats but is generally less frequent than lymphoma in older cats specifically. Thus, lymphoma stands out as the most prevalent hematological malignancy observed in the aging feline population.