Sheena -- my vet swears by the stuff and none of my ferts have gone deaf yet. The beauty of it is that it takes only two doses, one three weeks after the first. The mites die almost immediately, so the second dose is for any eggs that have hatched. No more weeks of ferret and human torture, with ear mite glop flung all over your shirt by a shaking ferret head. First he thoroughly cleans their ears, then he doses the ears using a syringe. Last week he did all five of mine at once because the new guy, Jake, had a bad case of mites. I haven't seen Jake leap up from a sound sleep to scratch his ears since. I am sure he is much relieved. Eloise and Sabine have been treated twice now and their little ears are as sharp as ever (when it is in their own best interests to hear anything at all). Hope that helps. Judith [Posted in FML issue 1597]