I use sentinel on my dogs. It gets kind of expensive, but, it is for fleas and heartworm. It's a monthly pill. I have just recently decided to stop giving it to the little dogs, as I don't really worry about heartworm with them, since they're hardly outside, and w hen they are, it's during the day, not night. I will keep the outside dogs on it though, and find something else to use for the 4 little ones, I can't stand fleas |