We used Hartz flea spray and spot treatment on our 14 yr old terrier mix about 4 weeks ago. He got around good, played with the kids and loved to eat!!! He started to become weak, especially his back legs, stopped eating and drinking and also layed around and didnt want to so anything. We ended up at emergency vet this weekend and he was in kidney failure, with his age the vet disnt think he could pull through this so today we had to say goodbye to him. If I knew that these products did this to other animals, i would have never purchased it. Do you know how hard it is when ur 4 yr old says” i dont want decter to die mom..