Protect your pet from dangerous flea- and tick-borne disease, such as Lyme disease, with Hartz First Defense topical treatment. Simply apply Hartz First Defense to your pet's skin once a month to kill fleas, ticks, and chewing lice. You'll also prevent and control re-infestation of these parasites for up to 30 days.
Hartz First Defense contains the active ingredient Fipronil, the same active ingredient in Frontline Top Spot. Fipronil is an adulticide that kills adult parasites (fleas, ticks, and chewing lice) by damaging their nervous system, which causes eventual paralysis and death.
Fipronil spreads with your pet's natural body oils over the entire body, killing 98-100% of the infesting fleas or ticks within 12-48 hours. Fipronil also collects in your pet's hair follicles, from which it slowly releases onto skin and hair for up to 1 month.
Hartz First Defense works quickly and lasts long. It is waterproof to stay on through baths and water play.
For dogs 8 weeks of age and older. DO NOT USE ON CATS.
Looking for First Defense for Cats?
Please click on "More Information" for ingredients, usage instructions, and additional product details.