Duke and Lars are brothers, 3 yrs old, ivory labs. They are healthy and very good boys. Last weekend I purchased Hartz Ultraguard at Walmart – I thought I had bought it in the past, but now see that the last application was Hartz (no ultraguard on the label). The ingredients in these two Hartz products are different. The Ultraguard has a toxin that killed my dog, Duke. Lars threw up twice the day after the drops were applied. Duke stopped eating 5 days after the application and after 2 hrs on IVs, died of internal bleeding. My son had to shoot his dog because he was suffering so badly, and we do not have a night clinic in town. He burried him in the back yard at 2am. It was the worst nightmare I could ever experience. I would have paid anything to save my dear boy, Duke. Now Lars is lost without his brother – it is a pitiful thing that a healthy beautiful dog had to die because of a product that is not safe. How can we get this off of the shelf?