I have bought frontline for several years and it has worked on my cats and kittens in the past. The last bach I received has not worked at all. I buy mainly Jeffers in America or from the vet. I spend a lot of money on this stuff and expect that my cats and kittens will not be covered with fleas. By the way, they don't have ticks, but they have not been outside. Something has changed with this product, because my cats, my kittens nor the space in which they live has not changed. Like I say, frontline use to work wonderfully, but at this time, it isn't working at all. Martha read full review »