Nexgard Spectra for dogs is a beef-flavored chewable for fleas, ticks and worm treatment. It is an effective treatment of Paralysis ticks, Bush ticks, and Brown Dog ticks. This monthly treatment is also effective in heartworm prevention in dogs, so you do not need to administer heartworm treatment for dogs separately. Nexgard Spectra combines two active ingredients, including Afoxolaner and Milbemycin Oxime. Afoxolaner is an ingredient that acts as an ectoparasiticide; meaning it kills external parasites such as fleas, ticks and mites. The other ingredient, Milbemycin Oxime acts as an endoparasiticide. This means that it kills parasites like worms that live inside dogs. It is effective for protection against roundworms, hookworms, and whipworms.