I had gotten Hartz flea and tick for my dog. Within 24 hours my dog started having Seizures. My dog has never had a seizure before until now. I took her to the vet and he told me to STOP using Hartz products because he has seen many animals that have never had seizures until the owner used Hartz flea and tick on their pets and now their having them. So in other words THIS PRODUCT WILL KILL UR FUR BABIES. DO NOT BUT THESE PRODUCTS.