I have been avoiding putting my dog on any type of conventional flea preventative for a while. I do not personally agree with the harsh poisons found in them. They do, after all, KILL bugs and are thus pesticides. I’ve had a very hard time rationalizing their use, especially since my dog has remained flea free. My train of thought had been, “Why mess with it until there’s a need to really do something about them?” I have been warned by the vet a couple of times, however, that waiting until I do see fleas is the wrong route to take. Once the fleas are present, they will be difficult to get rid of from my pup and my home.