Has anyone used or heard of this? It sounds dangerous to me.
Comfortis
Comfortis is a once-a-month pill for flea control in dogs. It circulates in the bloodstream and kills fleas when they bite. Comfortis is a relatively new product but early indicate that it's highly effective. Some dogs object to the taste, and some dogs vomit after it is administered, but Comfortis is the only monthly flea product that stays entirely within the dog - you and your family are not exposed. For many people this is a big advantage.