Completely unaware of the risk I used HARTZ Ultra guard on my one year old pit bull. Almost immediately he became moody and lethargic (which is completely out of character). Two days after the initial use he began to foam at the mouth and experience muscular fasciculation (seizures) followed by muscle weakness and vomitting. Right away I went into a panic. The only thing new introduced to his environment was the HARTZ. I was taken by surprise when I realized there was a warning lable under the basic lable. When the vet was contacted her first question was have you used any flea or tick treatments. She then, before I could tell her what I used began telling me horror stories she has seen in animals when their owners had used products containg organophosphate. Luckily he seems to be doing better today. How can it be legal to sell anything that could even remotely cause such a horrific and heartwrenching reaction?