I boycott any Hartz products because of my experience with the flea drops. I applied the Hartz flea drops to my cat (who was a 6 year old, 20 lb Maine Coon at the time) and within an hour he became lifeless. In a panic I called my vet. I started to tell them what was happening, and I kid you not the vet tech on the line said “you used the suicide drops didn’t you”. They told me to hang up and immediately apply a whole bottle of blue dawn dish soap on dry fur. Then wet him and lather him up. Wait 5 minutes then rinse, then bring him in immediately to be given IV fluids to flush his system. Luckily he survived. Once home and settled I started Googling these drops. What I found was so upsetting. I don’t know how these drops are still on the market. I don’t know how they don’t change their formula. Hundreds if not thousands of cats have died or almost died from these drops.