Make your cats health and comfort a priority with the long-lasting protection of the Seresto Large Dog flea and tick collar. Unlike other flea and tick protection Seresto Large cat flea and tick collars are vet-recommended stocked by 8 000 vet clinics * and have been trusted by pet owners for nearly a decade to successfully kill and repel fleas for eight continuous months.The Seresto Large cat collar works to kill pests on contact within 24 hours of application eliminating them before they bite your cat or lay new eggs.Seresto Large cat collars are for cats at least 7 weeks old.Seresto Large cat is a trademark of Elanco or its affiliates.