Flea & Tick Protection for Extra Large Dog by Defense Care 5-way protection against fleas/ticks/biting flies/mosquitoes/lice Kills and repels fleas before they lay eggs Repels and kills ticks including deer ticks, american dog ticks, brown dog ticks, and lone star ticks for up to four weeks Waterproof Repels and kills mosquitos, biting flies, and chewing lice