My cats name is Shadow. Last week I purchased a Hartz flea collar (as I always do this time of year) and 6 hours later he started howling and limping. he also was running into walls and was very, aggitated. I took him to my veterinarian Dr. Gaylon Simms here in Pell City and was told he had a stroke. He is paralyzed all the way down his right side. We take life day by day, he seems to be responding well to the medication, although we still have a long road ahead of us. I cannot imagine life without my “best friend”. Dr.Simms and I think it was the flea collar ( it was the only “new” thing done or given to him). Dr. Chastain, also here in Pell City, just had a similar case reguarding a Hartz flea collar, that story does not have a happy ending. Please DO NOT use Hartz products until we can find out what is hurting and killing our precious pets!