Beaphar Canishield® Dog Flea & Tick Collar is a veterinary medicine that kills fleas for up to 16 weeks, ticks for up to 6 months and sandflies for up to 5.5 months. Beaphar Canishield® contains the active ingredient deltamethrin, which is slowly released from the collar over time, providing long-lasting protection. For best results, use early in the season before fleas are seen, and at least one week before your dog is likely to be exposed to fleas and ticks. Suitable for all dogs from 7 weeks of age. For best results, use early in the season before fleas are seen, and at least one week before your dog is likely to be exposed to fleas and ticks.