How does Seresto® work? Seresto® has been developed using a mechanism of action: the active ingredients of Seresto® are released constantly and appropriately for up to 8 months, offering your dog up to 8 months of protection against fleas and ticks and, in dogs, also reducing the risk of infection by Leishmania infantum. 8 reasons to choose Seresto® Dogs It can be applied to puppies from 7 weeks old. Up to 8 months of protection Designed for the most adventurous dogs Eliminates fleas and ticks on contact, without needing them to bite the dog Protecting your dog can help protect your family Unscented, so nothing gets in the way of pampering. One worry-free app Composition (active ingredients) Collar for dogs ≤ 8 kg, 38 cm collar (12.5 g) contains 1.25 g of imidacloprid and 0.56 g of flumethrin. Collar for dogs > 8 kg, 70 cm collar (45 g) contains 4.5 g of imidacloprid and 2.03 g of flumethrin. Sizes Available in two formats: Seresto® Dogs +8kg weight Seresto® Dogs -8kg weight