I just published a story about my two cats who accidentally came in contact with Hartz drops through sleeping on a bedspread where a dog with Hartz appiled to it laid for a few hours. I want people to know that it is not only the cat variety of Hartz that will affect them. This was a drop designed for dogs and it was spread on some bedsheets and my cats simply came in contact with residue on the bedspread. BEWARE OF PUTTING HARTZ ON A DOG WITH CATS IN YOUR HOME! The Hartz can be spread and if your cats come in contact with it in some way they will have possible siezures, drooling, and even kidney/liver damage! BEWARE!!!!!!!!!