FRONTLINE® Shield for Dogs, from the #1 name in flea and tick protection*, is the fastest working FRONTLINE® product. It is proven flea and tick protection with repellency action against ticks and mosquitoes. FRONTLINE Shield repels ticks that may transmit Lyme disease and mosquitos that may lead to heartworm disease. The long-lasting, 3-in-1 flea and tick topical formula protects your dog for a full 30 days. It is an effective flea and tick treatment for pups big and small, effective for puppies as young as 9 weeks and weighing at least 5 pounds. After application, the treatment rapidly covers your dog's entire body and deposits in the sebaceous glands. These glands act as a reservoir, continuously replenishing the treatment onto your dog, working even if your dog gets wet.** Apply monthly to ensure your dog is protected all year long. So, no matter your plans, FRONTLINE Shield protects from fleas and ticks —inside your house, outside on walks and hikes, and everywhere in-between. Protect your dog with FRONTLINE Shield so you can go anywhere together. Subscribe and save today to make it easier to keep your dogs or cats protected year-round and make sure you never run out of FRONTLINE Shield. Be sure to visit our brand store and follow us to stay up to date on new FRONTLINE products, features, tips and more. References: * Data on file at Boehringer Ingelheim. ** Waterproof 24 hours after application