Seresto is a unique flea and tick collar for cats. The innovative collar is probably the longest lasting protection against fleas and ticks. This formula treats and prevents flea infestations for up to 8 months. Plus, it repels and controls paralysis ticks for 8 months. Seresto is an odourless collar that treats and controls flea allergy dermatitis and reduces the transmission of flea tapeworms and flea-borne disease (Bartonella Henselae). Within 24 hours of applying the collar, it controls flea infestation and kills 98% of existing fleas.