Choosing the perfect Dog flea medication is essential when your dog is infested with ticks. It’s important to consider your pets age weight, the life-cycle stage of the fleas, and any medical conditions that can affect your dog’s treatment. You can’t drive out a flea and so they have to come into actual contact with your dog’s flea medication to kill them. The fastest way to kill fleas on your dog is th have your furry friend take their flea medication in pill form. Topical treatments take at least 24 hours to begin killing fleas you only need to use it every couple of months. The classic way of dealing with flea’s ais our flea collars for dogs.