When our precious kitty “Sparky” was 3 years old, we purchased Hartz Flea & Tick and applied it to the nape of her neck. Within a few minutes she began falling over, not able to stand. To this day, she still wobbles when she stands and walks. I would like to see about filing or joining a lawsuit about this horrible product. Our pets are our babies and it is hard when you know you gave them something that you thought you could trust and would be safe but intead it cripples them.