I have a ShihTzu and I picked up Hartz Ultra Guard from my local grocery store. I was thinking that using Hartz would be safe since their products have been around forever, however I was nervous prior to using it, because I had never used this brand on my Abby prior to this. I always used whatever my Vet had at their office, this day I did not have time to go by the vet’s office. I applied according to thier directions. The next day Abby seemed like she was not feeling well, like maybe an upset stomach, I just kept a watchful eye on her. The 2nd morning I was going thru the normal routine and when I called her to go out to go to the bathroom she did not run to the door as usual. I walked into my room calling for her and she was laying under my bed and she would not move, she just stared at me. I picked her up and tried to put her down on her legs and she could not move her back legs at all. I was thinking ok, sometimes when you sleep in a weird position you are stiff. So I went to work and had my son sit with her all day. He kept trying to take her out all day and she would not stand on her back legs. My husband went home early to check on her and luckily she was able to stand, but still would not walk or go to the bathroom. By this time I called my vet to make an appointment, I got home and she was able to move a little better and finally go to the bathroom. The vet was going stay open late to see her and when I was that she was able to move better, I thought I would see how see did through the night,since my vet was opening early the next morning……LUCKILY my dog has gotten better, but I know this product is the cause of all of our worry, concern and stress. I was convinced prior to finding this website. I am so glad that someone started this site……if only I would’ve searched prior to giving my dog this poison that paralized her for a day.