Of all the diseases that can attack our feline companions, cancer is probably one of the most feared. In the minds of many pet owners, the word alone carries connotations of sadness and death. The good news is that not all types of cat bone cancer is deadly. In fact, some are quite treatable. Overall, the prognosis depends on the type of cancer, what stage it has advanced to and how healthy the patient is.
Several studies indicate that cats have an advantage over other species when it comes to bone cancer. In fact, less than one percent of all feline cancers involve the bone. Even when an aggressive form is diagnosed, cancer spreads much more slowly in cats overall. This translates into better prognoses and longer survival times than is seen in dogs.
Not All Tumors Are Cancerous
It is important to know that sometimes a cat can have a tumor on boney tissue that is not cancerous. The distinction is critical. A tumor represents an abnormal lump of localized cells. When these cells do not rapidly multiply and consume surrounding tissue, they are generally considered less threatening. Known as benign tumors, they are fairly unusual in cats. Surgery is the treatment of choice. Examples include:
- Ossifying Fibroma– a tumor that grows on the jaw bone. Symptoms are a hard, immovable and painless swelling in the area that distorts the face.
- Osteoma and Osteod Osteoma– begin tumors found in young animals. It’s usually seen in the head or facial region.
- Solitary Osteochondroma– Often seen on the skull or trunk region, and may extend down into the leg bones.
The Role of Vaccines In Cat Bone Cancer
In the mid 1990s, the American Veterinary Medical Association formed a special task force to study rising reports of vaccines causing cancer in cats. Their findings indicate that this is, in fact, the case- although the occurrence is very low. This lead to a overall revision of recommendations on what vaccines should be given and how often.
Most of the risk is attributed to Rabies and Feline Leukemia vaccines, which are very important preventative measures. The condition is called Vaccine Associated Sarcoma, which is a broad term that includes various types of Sarcomas. Osteosarcoma and Firbosarcoma, discussed below, have been linked to vaccines.
Feline Bone Cancer
Cat bone cancer is distinguished by whether it’s primary or secondary. Primary cancers originate in the bone tissue, while secondary ones start somewhere else and then spread. The origin is important, because it helps determine the most effective treatment. It’s also a good predictor for the likelihood of it coming back later.
In cats that have Osteosarcoma in the legs, amputation offers about a 50 percent cure rate. It depends on what is known as the “cancer free margin”, or the amount of healthy tissue between the cancerous lesion and the amputation site. Some studies suggest that amputation will prolong life by an average of 49 months or more. (2)
For those with Osteosarcoma in other bones of the body, called axial skeletal Osteosarcoma, the prognosis is much more bleak. Using traditional surgery, radiation and chemotherapy, some cases survive less than six months.
Feline Chondrosarcoma is another primary bone cancer found in cats, but it extremely rare. It represents less than three percent of all reported cancers. It’s normally found in the shoulder blades of cats, and amputation is the recommended treatment. Since there are so few cases, no cure rates have been suggested. Fibrosarcoma is seen a little more more frequently, but usually as a secondary type of cat bone cancer. Most originate somewhere else in the body and spread to bone.
The Role of Feline Leukemia
It is well established that Feline Leukemia Virus causes cancer of the bone marrow. Many cats with Leukemia do quite well, and go on to live comfortable lives. To what degree it plays a role in other types of bone cancer is not clearly understood. It is believed to be a contributing factor of Osteochondromatosis, mainly because most of these cats test positive. Osteochondromatosis presents with cancer lesions on a lot of different bones. The ribs, vertebrae and pelvis may be affected. Almost all of these cats die within the first year following diagnosis.
It is true that the body’s immune system has a natural ability to fight cancer all by itself. For a variety of reasons, the immune system will fail and cancer takes hold. Some research has indicated that spontaneous regression- not complete remission- has been reported in dogs. This lends credibility to the belief among alternative and holistic veterinary medical practitioners that some cancers may be treatable without chemotherapy and radiation.
Support for this among the veterinary community is conflicted, at best. Keep in mind that animals have a much shorter life span than humans, making swift treatment critical. The more advanced a bone cancer has become, the less likelihood there is for any treatment to work. However, many pet owners report a significant improvement in the quality of their pet’s life using holistic or homeopathic remedies.
If your cat has been diagnosed with bone cancer, you are going to face some very tough personal choices. Not every patient is an ideal candidate for treatment, and some owners are afraid of making their cat suffer. Others still are determined to pursue treatment options as aggressively as possible. There is no right answer. By arming yourself with knowledge, you have taken a step in the right direction.