Nexgard for Dogs and Puppies is a chewable, once-monthly tablet that uses Afoxolaner to control fleas and ticks. It also prevents future infestations. It's the only product approved by the FDA to kill ticks and fleas on dogs, and it prevents Lyme disease by killing potential disease-carrying parasites. It also controls infestations of American dog ticks (Dermacentor variabilis) and fleas (Ctenocephalides felis).