What is a Feline Fibrosarcoma?

Lisa wanted to share her retirement with an animal really in need of a home. She was glad to adopt a two-year-old formerly feral cat she immediately named Sammy. Although she needed to budget carefully since she was no longer working, she adored the cat and wanted to give him the best care possible. This included taking him to a local vet for vaccines beyond the standard ones he had received before being judged adoptable by a local rescue group. She sounded heartbroken when she called me to report that Sammy had developed a feline fibrosarcoma, probably as the result of an immunization.

What is a Feline Fibrosarcoma?

According to VetInfo.com. fibrosarcomas in cats are malignancies that spread very quickly. While veterinarians don't know why many of them develop, these tumors sometimes develop at site of a vaccination, much like a reaction to the immunization.

Fibrosarcomas in cats can appear in any bone in a cat's body but typically form in fibrous connective tissues of the ribs, pelvis, spine or skull. This type of feline cancer is considered very rare and unfortunately has fairly low survival rates.

Cat owners should be on the lookout for any of several symptoms in their pets. Among the signs of this type of malignancy are movements that suggest lameness or pain, particularly in the cat's legs, and an unexplained swelling in any of the animal's bones. The cat might experience difficulty eating and swallowing. Another sign is bleeding from the pet's mouth and/or a noticeable odor coming from the mouth, PetPlace.com reports.

Diagnosis and Treatment

An animal with any signs of a feline fibrosarcoma should be examined promptly by a vet. The doctor will take a history of the cat, then perform a physical exam that includes X-rays of the affected area and often of the chest and lungs as well.

Drawing blood for a complete blood cell count or a biochemistry profile is standard, as is performing a urinalysis. In many cases, performing a biopsy of the tumor is necessary to distinguish this type of cancer from osteosarcoma, which is much more common and which requires different treatment.

The standard treatment for a feline fibrosarcoma is surgical removal followed by radiation and chemotherapy. Pain medication is also considered a form of treatment. For cats that have gone through the traditional treatment regimen, VetInfo.com says the survival rate is only around 30 percent after a year and a half. Because the surgery might require removal of a limb and survival rates are relatively low, owners sometimes decide to forego this type of treatment and keep the cat as free of pain for as long as possible.

In the rare circumstance where a fibrosarcoma can be definitely linked to the site of a vaccination in a cat, the ongoing debate of which vaccines are really necessary can come into play. Those who are in favor of limiting immunizations usually maintain that the only one a cat should need is a yearly rabies vaccination.

Sources:

http://www.vetinfo.com/cencyclopedia/cefibro.html

http://www.petplace.com/cats/fibrosarcoma-in-cats-bone/page1.aspx

Personal experience as an animal rescuer