FiproGuard contains the same active ingredient as Frontline Top Spot. It is a trusted, effective way to kill adult fleas and ticks. It protects your cat against chewing lice as well. With Fipronil as the active ingredient, Fiproguard is a trusted, effective way to kill adult fleas and ticks. Plus, this treatment protects your feline against chewing lice as well so your furball can focus on spending time on fun and play, and spend less time focused on fleas.