Last summer we lost several cats and thought it might be predators as we live in a rural area. This summer again we have lost another half dozen cats… but they died in the house or on the deck. Just keeled over and dead within minutes. Guess what? They don’t die in the winter because we are not using flea stuff at that time. Hartz is probably killing many more than is reported… because the cats go outside and never come back. We are heartbroken, they are our babies, our kids. We treasure them and Hartz obviously could care less. They relabel and away we go. I also think Walmart and the other retailers bear some responsibility. We were using Ultra Guard One Spot (methoprene). Also, the US needs to stop buying Chinese formulations of pet products. Whether tainted wheat gluten or flea stuff, the Chinese don’t care about human or pet lives. Life is cheap for them. We will go with natural treatments from now on.