I have 3 cats, all of mature ages. They have recently become infested with fleas, so I went to the super-market last friday looking for flea drops for them. I found Hartz UltraGuard Onespot for eggs and flea larvae, and it was on sale, and I figured since it was sold in a large super market, it would probably be safe to use. I talked to my girlfriend about it, and told me that Hartz isn’t know for being a very effective product. I used the product specifically as directed, and put the drops directly between the shoulder blades and hoped for results. What I got was far worse. I went into the room they loll around in around 10pm on sunday night, and two of the cats came darting towards me as they knew it was dinner time. I didn’t see the third one up and about, so I looked for her. I saw her tail sticking out from the large bed they usually sleep under, and I went over to get her. I touched her tail and she curled in with it. I went under to grab her, and I felt her being very limp and became extremely concerned. I pulled her out and her eyes were as large as saucers, and she starting curling up and meowing frantically. I had no clue what was wrong with her, and the past few hours I have been trying to comfort her, as the nearest emergency vet is hours away, and the vet down the street opens early in the morning. I tried feeding her the wet food, and she was lapping at the gravy on it, and then she started meowing frantically and curling up as much as she could. She now shifts between laying there passively, with wide eyes and shallow breathing to frantically trying to call for help, and avoid whatever pain she is in. I looked up what could possibly wrong with her, or that if there had ever been problems with the Hartz product. I really should have researched this product more before using it. Once I saw that, I took the other 2 cats that wer I only hope that she does not pass away before I can get her to the vet clinic, and even then, that they can save her from this suffering.