I don't know...I just hate the idea of using any kinds of a chemical on a rabbit...they are so delicate and their skin is very thin, I'd be worried about poisoning. I think you are soing the right thing but just trying to comb them out, futile maybe but it's worth a try. If they get bad I would suggest you find a rabbit specialist vet and get advice from them. I think these products on rabbits are just too dicey to take chances with.