Pet Cancer

Common Cancers in Cats

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One in five cats will be diagnosed with cancer in their lifetimes. Just like with people, some cancers are more common than others.   Fortunately, with treatment, many cats can continue to live quality lives after a cancer diagnosis. Regardless of the cancer type, palliative treatments and pain management are always options to help prolong the quality of life for as long as possible.  

Lymphoma in Cats

Lymphoma is one of the most common cancers diagnosed in cats.  It is a cancer of the lymphocytes (a type of blood cell) and lymphoid tissues.  Lymphoid tissue is normally present in many places in the body, including lymph nodes, spleen, liver, gastrointestinal tract, and bone marrow.

The feline leukemia virus (FeLV) has been shown to cause lymphoma in some cats.  Cats with the feline immunodeficiency virus (FIV) are also at higher risk of developing lymphoma. Cats of any age, breed, and sex can be affected. 

Feline lymphoma can be divided into several different forms, which depend upon the predominant location of the tumor. Some cats have multiple sites of involvement and do not fit well into just one category. Lymphoma of the digestive tract is the most common form. The digestive tract includes the stomach, intestines, and liver, as well as some of the lymph nodes surrounding the intestines. Cats with this type of lymphoma may have vomiting, diarrhea, weight loss, or a decreased appetite.

Lymphoma is initially very responsive to chemotherapy, and approximately 70% of treated cats will experience remission. Most cats tolerate chemotherapy well and have minimal side effects. Serious side effects occur in less than 5% of the cats treated.  Side effects might include nausea, vomiting, and loss of appetite, diarrhea, tiredness, or infection. Cats do not lose their hair but may lose their whiskers and have a different texture to their fur.

Squamous Cell Carcinoma in Cats

Squamous cell carcinoma (SCC), which arises from the cells lining the oral cavity, is the most common oral tumor in cats.

Many cats with oral SCC will display signs such as drooling, foul odor, bleeding from the mouth, or difficulty eating. Some cats may present with symptoms suggesting a dental problem, and SCC is diagnosed as an underlying cause of the dental disease. A diagnosis of SCC usually requires a biopsy. 

Whenever possible, surgery is the first line of defense for SCC. Unfortunately, due to the small size of a cat’s mouth and the relatively large size of the tumor found most often at the time of diagnosis, curative surgery is possible in less than 10% of cases. When surgery is an option, it usually requires removing parts of the upper or lower jaw because of this tumor’s ability to invade bone and other deep structures in the mouth.

Radiation and chemotherapy provide additional treatment options. Unfortunately, very few cats with SCC can be cured. The goal with treatment is to maintain an excellent quality of life for as long as possible.

Fibrosarcoma in Cats

Fibrosarcoma is a cancer of the soft tissue. This tumor type is slow to spread to other parts of the body but locally aggressive. Owners will typically notice a skin mass that does not appear to cause pain or discomfort. When the disease is more advanced, cats can become dehydrated, lethargic, or anorexic.

In most cases, treatment for fibrosarcoma starts with surgery. However, even with aggressive surgery, the tumor often returns. As a result, radiation or chemotherapy is usually recommended as an adjunctive treatment. When therapies are combined, patients may live disease-free for one to two years.

Mammary Tumors in Cats

Mammary (breast) cancer is another common cancer in cats.  Almost 90% of feline mammary tumors are malignant, meaning they have the potential to spread to other parts of the body.  The most common sites of spread are the regional lymph nodes and lungs.  Around 10% of feline mammary tumors are benign, meaning they will not spread except by local growth. 

Surgical removal, at the earliest possible opportunity, is the most effective therapy for this type of cancer.  If the tumor is very small, complete surgical excision may be curative. For large tumors or when there is evidence of lymph node involvement, post-surgical treatment with chemotherapy may be recommended. 
 

Treatment for Pets with Cancer

Forty years ago, pets with cancer had few options. Today, veterinary oncology specialists around the country offer a variety of treatments. The Flint Animal Cancer Center’s comprehensive clinical practice offers advanced treatments in chemotherapy, surgery, and radiation for both common and rare cancers.

If you are concerned that your pet might have cancer, the best first step is to schedule an appointment with your local veterinarian.