Teresa - thanks, yes I have used it previously and never had a reaction before, even on Billy! And the other cats are fine. I didn't buy it from the vets, just a normal pharmacy (but have had it from my vet in the past, just more expensive there) so don't know if the vets will be a bit miffed that I'm not getting it from them. But if he needs treatment for it being burned I'd better give them a call Trigger - thanks I will do!