I had to have 1 of my 5, 4 week old kittens euthanized yesterday, and I believe it was due to Hartz KMR. I had just bought a new container of the powdered version, and had given them a few feedings from it. At 6am yesterday, I noticed 1 of them was sleeping in the litter box when I went into their room to feed them. I didnt think much of it, being little ones, theyre sometimes silly like that. So I startled her to feed her, and something was definitely NOT right. She was very limp, almost unresponsive…she took a couple sips of the KMR, but was more biting the nipple, as if to stop the flow of it. I think she knew better than I did of what was going on 🙁 I laid her on the heating pad, thinking maybe she was just extra tired or something. I went back in for their 11am feeding, and she was still in the same spot, looking lifeless, laying limply. I picked her up and she could barely meow. Her head and limbs just dangled, her eyes were open, but she was unresponsive, and had wet herself. I was so scared. I gave her a warm bath, to wash her mess off her, and thinking maybe she had some poo that needed to come out, and that the bath would wake her up a bit. No luck 🙁 I sat with her in this condition all day. After awhile her mouth started opening up and her tongue was starting to hang out a bit. Finally at 3pm, I took her over to the vet’s office. They checked her blood sugar levels, which were fine. Her temperature was a little low, but nothing super serious. They couldnt figure out what was wrong. In the end, the vet chalked it up to being a virus or some kind of birth defect, and suggested the most humane thing to do, was to put her down. So I did. I havent cried that hard in a long time. I brought her home, and buried her next to a flowering bush in our yard. I took a look at this website, thinking maybe it had something to do with the KMR. Then I went to our local pet store and bought PetAg KMR. Evening feeding time came around for the others, and as soon as I walk into their room, I see that the rest of them have the SAME SYMPTOMS. Wandering around the room, seeming confused, didnt really want to eat (but I did get them to take some of the other KMR), stumbling and falling over, lethargic. One was already laying on the floor, seemingly lifeless. I held her close to me for a long while, eventually wrapping her in my shirt I wore all day, and placing her on a towel in the cat carrier for the night. I was thinking I would wake up to them all dead. At 530 this morning, they had ALL come back to their normal selves, even the one I thought was surely going to die. I attribute it to having the different KMR in their systems, and the Hartz leaving their systems throughout the night. I lost one baby due to this HORRID PRODUCT. Never again! I will yell it from the rooftop that this product, and other Hartz products, are DANGEROUS KILLERS!!!!!!