I've put the spray in dog's ears on the advice of a vet; we had an ear problem we could not sort out. She said "well it won't do any harm". I've been told it is a practice done at ferret shows in France; the spray is put on a cotton bud and wiped around the inside of the ferret's ears. What is the problem with using Frontline in this way as it is not a systemic product? Chris. [Posted in FML issue 4870]