- Thousands of cats – from 1 to 10 out of every 10,000 vaccinated – develop vaccine-associated sarcomas each year. This malignant form of cancer is linked primarily to rabies and feline leukemia virus (FeLV) vaccines.
- Because of the risk of sarcomas at injection sites, it is customary for veterinarians to give feline rabies vaccines in the right rear leg and FeLV vaccines in the left rear leg. The injection sites are below the knee joint so that amputation of the lower part of the leg can provide a treatment option in the event a tumor develops. The majority of cat owners, however, when faced with a VAS on their pet’s lower leg, refuse to amputate to avoid pain, disfigurement, and the costs associated with the procedure.
- A recent pilot study at the University of Florida suggests that tail vaccinations are a good alternative to rear leg vaccinations in cats. Study results indicate there are no significant differences in the behavior of the cats that receive vaccinations below the knee and in the tail. All but one cat that received the tail vaccines developed protective antibody titers. The researchers concluded that tail vaccination was well tolerated by the cats in the study and was as effective as vaccines injected in the lower rear legs.
- The researchers believe tail vaccinations could make surgical treatment of vaccine-associated sarcomas easier and less disfiguring, which could in turn encourage more owners to have their cats treated for cancer.
- Rather than evaluating which body part is best for feline vaccinations, Dr. Becker recommends first focusing on the necessity for the vaccine at all. She offers guidelines to help you make sound vaccination decisions for your cat.
It is estimated that from one to 10 cats out of every 10,000 vaccinated will develop cancer at the vaccine injection site, also known as vaccine-associated sarcoma (VAS). A sarcoma is a type of cancer resulting from changes in connective tissue cells. Feline vaccine-associated sarcoma is a malignant tumor that is primarily associated with two vaccines: the rabies vaccine, and the feline leukemia virus (FeLV) vaccine.
For several years, it has been customary for feline rabies vaccines to be given in the right rear leg and FeLV vaccines in the left rear leg. The injections are made below the knee joint so that amputation of the lower portion of the leg can be offered to cat owners as a cancer treatment option. However, many owners of cats with VAS refuse amputation of their kitty’s leg because it’s painful, disfiguring and costly.
Pilot Study Suggests Tail Vaccinations Are Effective and Well-Tolerated
A research team from the University of Florida, Operation Catnip in Florida, Cornell University’s College of Veterinary Medicine, and Kansas State University’s Rabies Laboratory set out to evaluate alternatives to customary vaccine injection sites in the lower legs of cats. The results of their pilot study were published recently in the Journal of Feline Medicine and Surgery.1
The researchers surveyed oncology practitioners to learn their preference for vaccination sites based on ease of tumor removal. The preferred sites by 94 oncology practitioners were below the knee (41 percent), and the tip of the tail (30 percent).
Study results also indicated there were no significant differences in the behavior of the cats that received vaccinations below the knee and in the tail. All but one cat that received the tail vaccines developed protective antibody titers. The researchers concluded that tail vaccination was well tolerated by the cats in the study and was as effective as vaccines injected in the lower rear legs.
The researchers believe tail vaccinations could make surgical treatment of vaccine-associated sarcomas easier and less disfiguring, which could in turn encourage more owners to have their cats treated for cancer.
My Guidelines for Vaccinating Cats
As a holistic veterinarian, I’m much less interested in which body parts are best for vaccine injections than I am in determining which vaccines an animal truly needs based on established immunity, age, lifestyle, and other factors. This is especially true of cats, in light of the potential for vaccine-associated sarcomas.
If possible, I recommend you find a holistic or integrative vet to care for your cat. Non-traditional veterinarians are generally very cautious vaccinators. If your cat is strictly an indoor housecat with no exposure to other cats or the outdoors, the risks of annual vaccines far outweigh the benefits, in my opinion.
Ask for a vaccine titer test, which will measure your cat’s immunological protection against diseases for which he has already been vaccinated via his kitten shots. You can’t add protection to an already immunized pet, so don’t keep vaccinating.
If your pet truly needs a booster of a certain vaccine or a vaccine she’s never received, make sure that 1) the vaccine is for a serious disease (this eliminates many on the list immediately), 2) your cat may be in a position to be exposed to the disease (indoor cats have little to no exposure to most diseases), and 3) the vaccine is considered both safe and effective.
If your cat is an indoor/outdoor cat (in a high risk category for disease exposure) and must receive a booster vaccine, ask your vet to provide a homeopathic detox remedy called Thuja, which will help neutralize the effects of any vaccine other than the rabies vaccine. Rabies vaccines are required by law. There are two varieties of the same vaccine – the one-year type and the three-year type. Insist on the thimerosal-free, three-year rabies vaccine, and ask your vet about the homeopathic rabies vaccine detoxifier called Lyssin. If your pet is a kitten, ask to have the rabies vaccine given after four months of age, preferably closer to six months, to reduce the potential for a reaction.
If your cat lives entirely indoors, I recommend she not be vaccinated again after a full set of kitten shots in her first year of life. Her indoor-only lifestyle eliminates her risk of exposure to infectious diseases. Keep your unvaccinated indoor cat away from all other cats and your pet’s risk is virtually nonexistent.
Do not vaccinate your cat if he has had a serious vaccine reaction in the past.
Avoid veterinary practices that promote annual or more frequent re-vaccinations. Try not to patronize any boarding facility, groomer, or other animal care service that requires you to vaccinate your cat more than necessary.