For the past 25 years or so there has been a lot talk about how vaccinations are causing cancer in cats. As you would imagine this is quite a hot topic with many opinions. We thought we’d ask our favorite feline expert in all things cat-ish, Newton, to shed light (but not fur!) on this topic. People often ask us if we vaccinate our cats who are 100% indoor cats – we do not.
Newton’s Purrspective – The Hidden Danger in Vaccination
A veterinarian recently posted this on his Facebook page.
“Saw another fibrosarcoma induced by vaccination in a cat. That makes 13 in my career. Three in Florida all caused by other practices. None caused by Merial’s Purevax vaccines. Cat owners, I can’t warn you enough about learning what kind of vaccinations your veterinarian is using. ALL KILLED vaccines contain adjuvant. These are chemicals that sit in the area of the vaccine and cause chronic irritation and these tumors in low but significant numbers of cats. Ask what kind of vaccine is used. Ask to see the label before it is given. The type of vaccine is written on the label. If they won’t discuss it, run away. If they won’t show you the label, run away. Killed vaccines are cheap. If they use them they care more about keeping their costs down than the safety of your cat.” Peter Veling DVM
In the late 1980’s veterinarians in the northeastern part of the US started noticing cancerous tumors (fibrosarcomas) in young cats. This was surprising in itself, but these tumors were also occurring at sites where vaccinations are normally injected.
Why did this happen in the northeast? Well, there had been outbreaks of rabies in raccoons as well as feline leukemia in this part of the country. So without any scientific reason I can see many cats were getting these vaccinations yearly. Although the tumor is rare, a greater number of vaccinations administered increased the chance of a cat developing cancer. http://www.2ndchance.info/fibrosarcoma.htm
Why did the tumors appear at vaccination sites? The tumors are not caused by the antigen (e.g. rabies virus) itself. Killed viruses are often used, but to increase the immune response an adjuvant is added. This adjuvant also causes inflammation and sets the stage for a potential tumor.
I could find no evidence that trauma from the needle itself was related to cancer. However, your veterinarian should use the smallest needle (25 g) to make the injection as painless as possible for Kitty.
If caught early this soft tissue tumor can be removed surgically. However, it is extremely aggressive so the surgical excision must go far beyond the apparent boundaries of the tumor. http://theveterinarycancercenter.com/resource-center/vaccine-associated-fibrosarcomas-cats
How do veterinarians decrease your cat’s risk? Feline vaccinations are now done subcutaneously (under the skin) so any lumps can be detected earlier than if they are deep in the muscle. They are also injected as far down the leg as possible. (They are no longer given in the back of the neck.) If a cat does develop cancer amputation of the leg increases chances of survival. Tail vaccination (developed at the University of Florida) is a new alternative. http://sheltermedicine.vetmed.ufl.edu/education/research-studies/current-studies/tail-vaccinations-in-cats/
Vaccination protocols are under constant review and are revised by the American Veterinary Medical Association (AVMA) and the American Association of Feline Practitioners (AAFP). http://jfm.sagepub.com/content/15/9/785.full.pdf+html All kittens should be vaccinated since maternal antibodies only provide temporary protection. Adult cats should be examined yearly and only vaccinated if they are high risk based on their age and lifestyle. Antibody titers (obtained from a blood sample) can determine if your cat has adequate immunity.
Feline vaccines are also administered in locations according to AVMA/AAFP recommendations:
- left rear leg – feline leukemia (FeLV)
- right rear leg – rabies
- right front leg – distemper/upper respiratory (FVRCP)
- left front leg – reserved for any other needed vaccine
This aids researchers in determining correlations between tumors and certain vaccines. http://jfm.sagepub.com/content/15/9/785.full.pdf+html
What can you do to decrease your cat’s risk? Discuss the need for any vaccinations with your veterinarian. Please note that, despite human health concerns, feline rabies vaccination in NOT required in all states. https://www.animallaw.info/topic/table-state-rabies-laws-concerning-cats If you do not wish to vaccinate adult cats you can ask for an immunity titer. If you do vaccinate insist on vaccines that DO NOT CONTAIN ADJUVANT.