Virbac Preventic 25" Tick Collar for Dogs up to 4 Months Kills Detaches Ticks Wholesale X 5 Boxes Shipping From Thailand PREVENTIC 4 MONTHS TICK COLLAR Kills ticks, including dog paralysis ticks in dogs for up to 4 months. Paralysis ticks kill dogs. To save your dogs life use PREVENTIC 4 MONTH TICK COLLAR. It has an active constituent called Amitraz which inhibits the tick from 'feeding' on your dog. he tick does not need to bite the dog to be killed by Amitraz. PREVENTIC detached and removes ticks before they infect. And it works continuously for up to 4 months.