Bravecto chews for dogs Kills All Adult Fleas Within 8 Hours and Ticks in 12 Hours, Bravecto Gives Total Protection For Up to 3 Months. Bravecto has Fluralaner as its active ingredient. Fluralaner kills old and new fleas for 12 weeks. It also reduces egg production and kills American dog ticks, brown dog ticks, and black-legged ticks. Treatment with Bravecto Chews may begin at any time of the year and can continue year-round without interruption.