Feline Medicine's Dirty Little Secret

Lynn Schneider

Posted August 1, 2003

Feline Vaccine Associated Sarcoma (VAS) is an aggressive cancer that often occurs at vaccine injection sites in cats. It was first noted in 1991 at the University of Pennsylvania College of Veterinary Medicine after Pennsylvania mandated annual rabies vaccinations in 1987.

Two years earlier, in 1985, vaccines containing an aluminum-based additive were approved for use. This additive – called adjuvant – was added to stimulate the cat’s immune system to provoke a more profound response. The World Health Organization classifies these aluminum-based additives as carcinogens.

It wasn't long before other vets began to report similar tumors.

In 1996, a task force was created from a wide cross-section of the professional veterinary community to study this cancer. In the March 1, 2001 issue of the Journal of the American Veterinary Medical Association, the Vaccine Associated Feline Sarcoma Task Force published a report reviewing it's history, research, and clinical recommendations.

Research has been promising, yet daunting and slow. A possible genetic tendency for cats to develop this cancer is under study. Cancer from injections of medications other than vaccines are also being studied. Steroids with an additive called the "respositol fraction" have also become suspect in the development of some of these cancers.

In the late 1990s, vaccines without these cancer-causing additives became available. Yet today, less than 10% of veterinarians in the USA are using these products, even though vet schools across the country are gradually switching to exclusive use of these safer vaccines.

In 1998 and again in 2000, a group of veterinary professionals known as “the American Association of Feline Practitioners (AAFP) and the Academy of Feline Medicine (AFM) Advisory Panel on Feline Vaccines” published vaccination guidelines for veterinarians.

Despite all of the research, the introduction of additive-free vaccines and the vaccination guidelines, veterinarians across the country continue routine use of vaccines containing adjuvant. Scruff shots are not a recommended vaccine or drug injection site for cats, yet many vets continue this practice. Many continue to administer vaccines that are not recommended for routine use in cats. They continue these practices without informing cat owners of the potentially fatal complications.

Incidence statistics vary so widely that they are meaningless. Discussion of statistics often leads to failure to address the issue. Many vets routinely minimize this disease by calling it "rare", which means little when your cat is on the losing end of the statistic.

Sadly, in 2003, the American Veterinary Medical Association has withdrawn funding from the task force that it helped to create, essentially bringing research efforts to a disappointing and premature close.

Cats continue to die from this largely preventable cancer. Guardians are paying thousands to save them. Vaccine manufacturers reimburse guardians a portion of their veterinary expenses, but the amounts vary and some require that the guardian sign a waiver, preventing possible litigation.

VAS remains largely un-discussed in veterinarian exam rooms, excluding guardians from a say in the matter. It remains the well-kept dirty little secret of feline medicine. Cats continue to be injected with carcinogens and left with a death sentence, while guardians are left holding the bill.