Never heard of turmeric for wounds - just for good health while eating. I guess if I were in your shoes I would ask a vet - if nothing else to ask about a safe dose.
Bear in mind, this article at the NIH is written for use in humans, so doses would not be appropriate for cats. I know you're asking about using it topically, but just in case anyone stumbles on the thread, just thought I'd put that out there.