My cat Mackenzie almost died from Hartz flea meds. I put the medication as told on her. Not long after that she had a severe reaction to the meds. It made her have tremours and she couldn’t walk. If she tried she fell over. Her heart was racing. I took her to the vet, told them what I gave her. My cat almost died that day! If I wouldn’t have taken her in as soon as I did, she would have died. She was in the hospital for days. We didn’t even know if she would make it or not. They were not sure if after they took her off support she would be okay or if the tremors would start again. Luckly I got her the care she needed and she made it. But they told me while I was there about the many pets that are brought in and dont make it. The people of Hartz should be damn ashamed of themselves for putting out this product. If I lost my baby I dont know what I would have done.