Just wanted to post a little testimonial. I purchased some Bug Check at Horse Fair in Madison WI last month. My husband saw the "guaranteed against ticks" part. Our farm is literally carved out of a woods. We are surrounded by woods and picking ticks off horses has always been a daily activity here. A hammer and steel plate for tick squashing is just a part of my grooming tools. I started the mares on Bug Check just about a month ago and have to tell you I have picked off ONE tick off ONE horse since then. And it was dead??? I never believe marketing claims but am so happy my husband was so positive it wouldn't work =) We have also thus far noticed there are no gnat bites. Usually the girls are all chewed up by now. We sat and watched the other night and the flies are landing on them however they are not biting. I can't wait to see how the deer and horse flies react. THANK YOU SO MUCH Dr Dan for making my mares a whole lot more comfortable. I never actually believed it would work either. 35 years of owning horses and I finally found something that works. Thank you.