I wanted to post a story telling why hartz is an awful product to use. I work for a vet hospital in sacramento. and i can say first hand what this product can do to an animal. I have seen some pretty bad cases. The most common are siezures and tremors. If you have applied it ,WASH YOUR PET ASAP!!!! and then get to a vet hospital, and NEVER use it again. Thank you for this web site, i think it will help alot of people, i have found out that alot of users dont know that it is a dangerous product until its to late. The safest flea and tick products are only sold at your local vet hospital, it may a little more expensive, but its worth it in the long run.