Give your dog long-lasting protection against fleas and ticks with a Seresto Large Dog flea and tick collar. Unlike other flea and tick protection, Seresto Large Dog flea and tick collars kill and repel fleas and ticks for eight continuous months. Seresto Large Dog flea and tick collars are recommended by veterinarians, stocked by 8,000 vet clinics* and have been trusted* by pet owners for nearly a decade. Seresto Large Dog collars make your dog?s comfort a priority by killing fleas and ticks on contact, so pests don?t have to bite your dog to die. Existing fleas die within 24 hours after initial application of the collar. After 24 hours, any new fleas on the dog are killed within 2 hours with protection against further flea infestation lasting 8 months. The prevention of infestations with new ticks starts at 48 hours after application of the collar. 48 hours after application, any new ticks are repelled and/or killed in as quickly as 6 hours. Seresto Large Dog collars protect against common pests like d