Vaccination and fibrosarcomas in cats

Risks of fibrosarcomas from vaccinating are less than risks of not vaccinating cats

source: Veterinary Record vol 148 no16, April 21 2001 p493

Jane Dobson from Cambridge University's Department of Clinical Veterinary Medicine, has reviewed literature on links between vaccination and fibrosarcomas in cats. She presented her report to the 2001 BSAVA Congress. She noted that there was a study in California which found cats vaccinated against rabies to be more likely to suffer from fibrosarcomas that were often larger and more aggressive, and affecting younger cats, than traditional fibrosarcomas. Sarcomas also seem more likely to occur if a cat is always vaccinated in the same spot, possibly because the injection site could become affected by chronic inflammation. There is evidence for some sort of link between vaccinating and
fibrosarcomes, but no actual proof. The development of cancers probably involves a number of factors, she argues. Reported cases in the UK that fit a diagnosis of fibrosarcomas induced by vaccination are rare. Cats are exposed to greater health risks if they are not vaccinated, compared to the risk of their developing a tumour.