Yesterday morning i put a hartz ultraguard flea and tick collar on my rescue Brussels griffon mix and within minutes he started behaving strange. ..he ran outside and started stumbling fell on his face trembling seizing and convulsing I immediately took the collar off and after awhile he stopped seizing but remained lathargic and quite sickly. ..he is usually a very active happy high energy dog…he has extreme vet anxiety (needs to be sedated and given oxygen everytime) so I decided not to take him but just to watch him closely..I sent hartz a private FB message with videos and pictures and i emailed them twice and called them this morning. They said his reaction was not something that usually happens and that they don’t see this kind of thing and kind of hinted that my dog probably has an underlying issue. Not a doubt in my mind My dog was poisoned by that collar..the reaction was almost immediate and absolutely devastating to witness. I know if I hadn’t taken that collar off he would have died..oliver is a happy healthy dog..but today he’s having trouble walking and remains lethargic and totally not himself… they didn’t even offer to pay the vet fee if I took him but that would be like admitting guilt of sorts..I knew there had to be other issues with this product and that’s how I found this page…my dog almost died yesterday and hartz doesn’t care!