Does anyone know if Revolution (selamectin) treats parasites like the Demodex mite? The website says it's for fleas, ear mites, heartworms, roundworms and hookworms. The vet is pushing me to try it for my cat's itching and scratching problem of the head, face, neck, and back of ears. He thinks he could possibly have that Demodex mite or some sort of parasite other than fleas and ear mites that Revolution would take care of. He said I could try a tube for free so it's not like I'd be losing any money if it didn't work. But I don't like giving my cat something that enters the bloodstream if he doesn't need it.