Hi, I have been hand raising four two week old puppies since their birth and have been feeding them milk replacer from the vets and they all have been thriving excellent. I ran out of the esbilac and purchased the hartz milk replacer from walmart. As soon as I started to feed them the hartz they shook their heads and swallowed a few drops and acted like it was poison. I continued trying to feed them, thinking maybe it’s just the taste difference. When I put one of the puppies down in its bed, he became very uncoordinated. They are all very listless now and I don’t know what will happen. I stopped the formula immediately. I will post updates.