Cancer in Cats

Cats and Cancer

by Margaret Schill

Cancer begins when abnormal cells in a part of the body start to grow out of control. Cells become cancer cells because of damage to the DNA in the cells. Normally, when DNA in a cell gets damaged, the cell either repairs the damage or the cell dies. In cancer cells, the damaged DNA does not get repaired, the cell doesn't die like it should, and it goes on making new cells with the same damaged DNA.

Cancer is not necessarily a death sentence! Some cancers of cats can be cured, with the cat living a normal, healthy life for years after treatment. Early detection is important so that proper treatment can be initiated immediately before the cancer progesses to a stage where it is no longer treatable.

Cancer can arise in any part of the body and produce a wide variety of signs and symptoms according to the type of cancer present and where in the body it is located. Some of the changes are specific, such as an obvious lump, but others are more vague and can mimic other disease processes. Do get any lumps appearing on a cat checked by a vet.

Ten Common Signs of Cancer in Small Animals

From the American Veterinary Medical Association

Abnormal swellings that persist or continue to grow
Sores that do not heal
Weight loss
Loss of appetite
Bleeding or discharge from any body opening
Offensive odor
Difficulty eating or swallowing
Hesitation to exercise or loss of stamina
Persistent lameness or stiffness
Difficulty breathing, urinating, or defecating

Many of the above symptoms will be found in other diseases. The veterinarian will need to perform tests to determine why a cat is having symptoms. The vet will conduct a physical exam. Next, one or more diagnostic methods may be used, including blood tests, x-rays and CT scans, and biopsies if there is a lump or mass.

Good nutrition is especially important for cats with cancer, so if you feed dry food, forgo the typical grocery store dry cat foods and purchase top level premium cat food, often only available in pet stores. Cancers are most able to use carbohydrates as an energy source, so low carbohydrate diets are best for cats with cancer. Typical grocery store dry cat foods are high in carbohydrates (grains). Select foods with no grains, or almost no grains. Wellness CORE and Innova EVO are some top quality, grain-free dry foods. Note, however, that no-grain cat foods are very high in protein, which is not good for cats with kidney failure.

Cancer of the Skin and Subcutaneous Tissue (Squamous cell carcinoma)

Squamous cell carcinoma can occur anywhere on the body (as skin cells are squamous cells) but is usually found in the mouth, on the nose, and on the tips of the ears. If diagnosed early, squamous cell carcinoma can be cured.

Ultraviolet light from strong sunlight can induce squamous cell carcinoma. Even though windows filter out ultraviolet radiation, most do not filter out enough of the radiation in the case of squamous cell carcinoma. White or light haired cats are more commonly affected with involvement of the tips of the ears and the nose. White cats should not be allowed in strong sunlight too often.

Small lesions on the tips of the ears and nose can be removed surgically. Do not delay in taking a cat to the vet if you see any lesions or lumps. If allowed to grow larger, it might be too late for a cure.

Signs of squamous cell carcinoma in the mouth can include reduced appetite, reluctance to eat on the affected side of the mouth, drooling, bloody discharge in the mouth, and a foul odor from the mouth. People often suspect a dental problem, and might put off taking a cat in for a dental exam, due to financial concerns. But if the problem is actually due to squamous cell carcinoma, if the lesions are not treated in the early stage, it will be too late. If caught early while the lesions are small, they can be removed.

More information:

http://maxshouse.com/tumors_of_the_skin.htm

http://www.moorevet.com/Feline/scc.html- includes pictures

http://www.merckvetmanual.com/mvm/htm/bc/72205.htm

Feline Mammary Tumors

Any mammary lump, mass or swelling noticed on a cat needs prompt vet attention. Do not wait! Mammary cancer is aggressive and spreads quickly. If it progresses to later stages, the outlook for survival is low. At least 80% of feline mammary tumors are malignant. The sooner the problem is treated, the greater chance for survival.

Mammary tumors in cats often appear as firm nodules that are moveable or firmly attached to the skin and/or underlying muscle. There may be swelling, infection, pain and fever as well.

The majority of affected cats are intact females. There is a strong correlation between early spaying and a reduction in the incidence of mammary tumors in cats. So, spaying female cats before their first heat can reduce the chances of that cat developing mammary cancer. Male cats can also develop mammary cancer, though it is rare.

More information:

http://www.peteducation.com/article.cfm?c=1+1376&aid=220

http://maxshouse.com/Oncology/feline_mammary_tumors.htm

Feline Lymphosarcoma

Lymphosarcoma (lymphoma) is one of the most common cancers diagnosed in cats. It is a cancer of a type of blood cell called lymphocytes (a type of blood cell), and of lymphoid tissues. Lymphoid tissue is normally present in many places in the body. Lymphosarcoma is divided into several different forms, depending upon the primary site of the tumor.

Gastrointestinal
Mediastinal (in the chest)
Renal (Kidney)
External lymph nodes
Bone marrow

Lymphoma is graded as either high-grade, low-grade, or intermediate grade. The grade refers to how rapidly the cells appear to be dividing and how malignant they appear, with high grade being the most malignant. Lymphosarcoma is very responsive to chemotherapy and up to approximately 60% of treated cats will go into remission. As a general rule with lymphoma, higher grades tend to be more responsive to chemotherapy drugs. With feline intestinal lymphoma, however, it is the low grade cases that are capable of fairly long remissions.

Some websites say that survival is reported to be around six months. But, the sites did not say what types of lymphoma they were referring to, or if that was also the case where it was an intestinal tumor that was fully removed. Our cat Sumner had high grade Lymphosarcoma in his intestines, the tumor was removed, no chemotherapy was given except for some prednisolone for a few weeks, and at the time of this writing, he is fine 11 months later!

More information:

http://www.marvistavet.com/html/body_feline_lymphoma.html

http://www.oncolink.org/types/article.cfm?c=22&s=69&ss=545&id=6019