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June 6, 2024 – Cancer is a leading cause of death in cats but often is overshadowed by other health threats like diabetes or kidney disease. And some experts even claim it’s the second most common cause of death in older cats!   

Pet parents need to know about some of the more common types of cancer affecting cats to help keep their feline family members healthy. Let’s look at four critical malignant cancers in cats: oral squamous cell carcinoma, lymphoma, soft-tissue sarcomas and mammary carcinoma.  

Feline Oral Squamous Cell Carcinoma
FOSCC is a cancer of the mouth and accounts for 70% to 80% of all feline oral tumors. This cancer can move slowly, but it burrows deep into the bones of the jaw and oral cavity, making it nearly impossible to remove surgically. Though chemotherapy is ineffective against FOSCCs, they respond well to radiation, so surgeons often combine surgery with radiation to control the tumor. Prognosis is terrible, with less than 10% of cats diagnosed surviving longer than one year.   

Morris Animal Foundation has funded several studies in the last few years specifically focused on finding new ways to treat this cancer. Our active grants include surveying a new strategy for delivering radiation therapy that improves outcomes while minimizing side effects. Another study uses light-triggered particles to target and kill cancer cells. We’re hopeful these studies can improve the odds and quality of life for cats with FOSCC.   

Feline Lymphoma  
Feline lymphoma is one of the most common and deadly cancers of cats. Lymphoma can take many forms, but most oncologists agree that gastrointestinal lymphoma is seen more often in cats. Less common forms of feline lymphoma include mediastinal (enlarged lymph nodes in the chest cavity), multi-centric nodal forms (involving multiple lymph nodes), and miscellaneous forms such as nasal, kidney and central nervous system.  

Lymphoma is treatable, and in some types of gastrointestinal lymphoma, cats can live several years with an excellent quality of life and minimal treatment. Other forms, such as those involving the nervous system and chest, rapidly progress and are challenging to treat.   

Soft-Tissue Sarcoma  
Soft-tissue sarcoma is a broad classification for tumors in cats' skin and connective tissues. These tumors tend not to spread to other tissues quickly but infiltrate local tissues, making removal difficult, especially if they’re on the cat's trunk, head or neck. Injection-site sarcomas are one type of cancer that fall in this category.  The prognosis for these tumors can vary a lot. For example, amputation can be curative if the cancer is on a limb. In other cases, radiation therapy can assist.   

Mammary Carcinoma  
It might surprise cat owners to know that mammary cancer is the third most common type of feline cancer. It is almost always malignant, with very few mammary masses considered benign.  

As in dogs, mammary cancer is more common in intact cats but also occurs in spayed animals. Surgery is the primary method to address these tumors, and the prognosis can be excellent if the disease is caught early. Unfortunately, many cancers in cats are advanced when they’re diagnosed.  

Science to Save Animals Starts with YOU     
Sadly, an estimated six million cats are diagnosed with cancer each year. Veterinarians have limited treatment options due to a lack of funding aimed explicitly at cat cancer.   

Morris Animal Foundation is one of the few organizations that fund research on cat cancers, and we’ve been advocating for our feline friends for over 75 years!   

Our early support for developing an effective vaccine against the feline leukemia virus has helped reduce the incidence of leukemia in cats around the world. Our team continues to look for the best and most innovative research to help cats live their best (nine) lives!   

However, there’s so much more we need to learn and your help.     

Will you join us in funding the science we need to save more lives?       



Fresh Scoop Podcast Episode 33: Exploring a New Diagnostic Tool for Use in Treating Feline Injection-Site Sarcomas  

Fresh Scoop Podcast Episode 54: Environmental Toxins, Cancer and Pets  

Fresh Scoop Podcast Episode 56: Lymphoma in Cats and Dogs