About 3 years ago I used Hartz on our 4 little dogs (poodles and yorki-poos). At first we had no problems and it seemed to get rid of the fleas also. My oldest poodle was 7 at the time and she had one tiny cataract on one eye, my daughters’ male yorki-poo had had seizures a couple of times in the past, my little Huckleberry had had a lot of problems since birth but looked like he was finally better and was a little ball of energy, and our other little female was healthy and had no problems. Within 3 weeks after putting the Hartz drops on our dogs, 2 of them had serious problems and one of them died. My oldest poodle went from having the one cataract on one eye to being completely blind, my daughters male was playing outside in our yard and suddenly lost the use of his hind legs and my little Hucklyberry, who was such a sweet and silly little dog, I found dead. I had him in the pen outside and heard him doing a lot of barking and a little later when I went out to bring them all in, he was laying dead. I didnt not know about this website until a couple of weeks after I had put the product on them and beings it had been that long, I didnt think anything would happen. It seems as though most pets develop problems quickly after the drops are put on them. The drops seemed to only affect our dogs that had some sort of issue already. My little Huckie was my baby and I still miss him a lot. He was so full of life and was not even 2 years old yet. Thankfully, although my daughters dog does still have some weakness in his hind legs, he did eventually regain the use of them. If you have used these drops, keep an eye on your pet for weeks afterwards. Like I said, our problems didnt occur right off, they all happened within 2 to 3 weeks after using the drops.