I have used this product on both of my dogs. We live in a wooded area on a farm and from my experience, it does not work well at all. We have pulled many many ticks off of our dogs while on this medication for months!! I called the company and they said the ticks has to bite the dog first then they will die. I do not believe that works!! If they bite the dog, then they have a chance of getting diseases!! A repeller would work best! And this product is very very expensive!