I use the kitten dose of Revolution on my ferret. She as adrenal disease and the only "reaction" she has had to the Revolution is a slight reddness to her skin where I have applied it. Advantage is has also been dispensed for ferrets at my hospital. I personally chose Revolution because it also protects against heartworm disease. Living in TX I have mosquitos in my apt. every now and then. Stacey [Posted in FML issue 3821]