Seresto 8-Month Flea & Tick Collar for Dogs

Seresto Dog Collar | 8-Month Continuous Flea & Tick Protection, No Prescription

Quick Facts:

• Best for: Dogs 7 weeks and older
• Main active ingredients: Imidacloprid & Flumethrin
• Format: Wearable collar, 8-month continuous protection
• Key support: Kills & repels fleas, ticks & chewing lice by contact (no biting required)
• Prescription status: Not required — available over-the-counter
• Ideal for: Owners wanting to skip monthly reapplication in favor of a single long-term collar

Description: Seresto takes a fundamentally different delivery approach than a monthly topical or oral chew: rather than reapplying every 30 days, the collar continuously and slowly releases its two active ingredients — imidacloprid for fleas and flumethrin for ticks — across the dog's coat and skin for a full 8 months per collar. Because pests are killed and repelled through contact rather than requiring a bite first, Seresto is positioned as working before a flea or tick can transmit disease, rather than after. It starts killing and repelling fleas within 24 hours and kills reinfesting ticks in as few as six hours, and remains water-resistant through swimming, bathing, and rain, though the brand notes protection duration shortens somewhat (to 5 months for fleas, 7 for ticks) if a dog is bathed or swims more than once a month. It's approved for dogs at least 7 weeks old and requires no prescription, and is separately sized for dogs under and over 18 lbs to ensure appropriate dosing by weight. For households that find monthly topicals or chews hard to keep track of, the set-it-and-largely-forget-it nature of an 8-month collar is the product's core appeal — though it needs to be properly fitted using a 2-finger-gap rule to stay effective.