Bayer Seresto Flea and Tick Collar for Dogs Seresto small dog flea collar provides 8 months of continuous flea and tick protection Bayer Seresto collar kills and repels fleas and ticks through contact so they don't have to bite your dog to die Low concentration, continuous release formula with imidacloprid and flumethrin spreads from head to toes, even the tail, over your dog's coat and skin Seresto flea and tick dog collar also aids in the treatment and control of sarcoptic mange and kills lice Vet-recommended flea and tick protection for dogs in a convenient, odorless, non-greasy collar, no need for monthly treatments