Protecting your dog from pests is easy with Vectra 3D for Dogs, Tick & Mosquito Treatment & Prevention for Extra Large Dogs! This monthly topical treatment is formulated to protect your pup from fleas, ticks, mosquitoes, lice, mites plus biting and sand flies—no prescription required. The fast-acting formula works to stop flea biting in five minutes and kill fleas in four hours. Plus, the repellant action helps prevent insect bites, defending your dog from flea allergy dermatitis, flea bite anemia, tapeworm disease, Lyme disease, Rocky Mountain spotted fever, heartworm disease and more. You’ll also love that Vectra 3D is fragrance-free, non-greasy and waterproof 24 hours after application. Each dose of Vectra 3D protects your dog for one month and is a great solution for indoor dogs as well as dogs that love the outdoors. Your dog should be at least eight weeks old and weigh over 95 pounds to use Vectra 3D Extra Large Dog.