I wish I had seen this site before using Hartz products. I’ve been battling a flea problem all summer using a variety of products over the counter and from the vet with limited success. I bought some Hartz flea and tick dip for CATS and dogs from Wal-Mart. I proceeded to dip my five year old cat Sandy. I followed the directions properly, and I thought all was well until I could not find her for two days. I thought she was just mad that I bathed her but two days later she returned, but her balance was slightly off. I didn’t realize at the time what was happening. Later that day I noticed her muscles twitching all over her body and as the hour went by, she began to lose all control of her balance and coordination. I got online and looked up the symptoms, and I read that toxic reactions to the flea treament can be delayed 48 hours. I bathed her and kept a close eye on her. She began to get much worse by the minute. I called the vet who told me there is nothing to reverse the toxicity but he could give her atropine and something for seizures if necessary but mainly to ride it out and call back if I was going to bring her in. He also said to bathe her which I did again. I made her comfortable and monitored her all night. She never seized but the muscle spasms were severe. She couldn’t even meow. By morning she was beginning to recover. Her coordination slowly improved, and now she is back to normal . I will never use Hartz products again. I kept the bottle of flea and tick dip to show anyone who comes over what NOT to use.