I bought Hartz Gold Flea Treatment for my three dogs. I purchased the appropriate strength for each of my dogs, administered the drops according to direction and all three dogs became severely ill within approx. 2-3 hrs. All three dogs foamed at the mouth. I could tell by their behavior that they were also in pain. My largest dog seized after about 4 hrs. Small repetative seizures. My medium sized dog became lethargic and hid for approx. 12 hrs. My smallest dog, a chichuahua, had so much foam coming from her mouth, that she began to aspirate on it. She was in a panic, as she could not breathe. She had saliva and foam coming from both her nostrils and mouth. I used a baby nose bulb to suck as much foam out of her nose as possible and gave her repeated hot baths with shampoo, to hopefully rid her coat of the toxic substance that had not yet soaked in. She was better within about 2 hrs. Approx. 4-5 days later, I noticed that all along where I had applyed the Hartz gold down the dog’s backs, the skin had completely burned off, leaving harge tracks of scabs where the wounds were clotted from blood oozing out. Hartz should be sued. They are endangering who knows how many dogs and cats’ lives.