Unlike the older more toxic products, Advantage and Frontline are not absorbed into the pet's bloodstream. They remain on the surface of the skin where they are purportedly toxic only to the fleas. Both products claim to be safe to use on cats and dogs. Advantage's active ingredient, Imidacloprid, and Frontline's active ingredient, Fipronil, are new chemicals and as of yet, no studies have been found to show any adverse health effects on humans or pets. They work by interfering with nerve transmission in adult fleas by killing them and the flea larvae.
Program is given as a pill to the pet.
Lufenuron, the active ingredient in Program, is absorbed in the animal's bloodstream. This prevents the fleas' eggs from hatching. One caution to consider before choosing this method is that lufenuron can accumulate in fatty tissues of pets, causing adverse effects such as vomiting, depression, diarrhea and skin irritations. Seek out and try the safer methods first, or consult your veterinarian. Mary Meuting is an animal lover and an Ecology Center volunteer.