I'm sorry that your cat has been poorly, I hope he/she makes a full recovery soon.

According to an article in the Canadian Veterinary Journal, Sarcomas have been reported as having developed between 3 months and 11 years after a cat has been given a vaccination.

It also states that the prevalence is believed to be somewhere between 1 in 2000 and 1 in 4000 in vaccinated cats. I have never been made aware of any risk when my cats have had their jabs.

The full article can be found here

http://www.pubmedcentral.nih.gov/art...medid=13677599