It is not possible to prevent ticks initially attaching themselves to pets particularly in tick infested areas such as woodlands & moorland, but wearing a Johnson's Water Resistant Tick Collar will then kill ticks, & fleas & help to prevent further infestation for up to 4 months. However, it may take several days to be fully effective while the active ingredient spreads throughout the entire coat. Therefore, check pets daily for infestation after exercise, & it is also advisable to remove any new ticks that may have attached themselves. This is easily & successfully achieved with the twisting action of a Johnson's Tick Remover, ensuring that the whole of the Tick is properly & safely removed, for disposal in household waste.