We have two large breeds, and they stay outside, so it was hard to find an "OTC" product that worked. With the flea/ tick collars from Revival Animal Health we found just what we needed. It keeps them free from the irritation of flea bites and keeps ticks from sticking to them also, from their head to their toes (paws). Our next endeavor is checking Revival's Equine products, we have found our horse will not let us spray him down for horseflies, he is leary of a spray can, and he is too skiddish to let us get close enough to rub something on him, we are thinking maybe a pump spray that doesn't make any noise. I give them the highest rating, and I recommend Revival Animal Health care to anyone who needs the best, working products for their furry friends.