I bought Hartz Flea and Tick collar yesterday and in a few short hours my cat began acting funny. She was wobbly and couldn’t walk or even open her eyes all the way. As I type this she is at the vets office on IV’s and we are waiting to see if the antidote works and she makes it. It appears that the collar has poisoned her. I am appalled that this company has been able to sell this product after reading all the post. I will never again use a flea or tick anything on my animals.