Frostbite begins when the dog’s body gets cold. The body automatically pulls blood from the extremities to the center of the body to stay warm. The dog’s ears, paws or tail can get so cold that ice crystals can form in the tissue and damage it. The tricky thing to remember about frostbite is that it’s not immediately obvious. Watch for signs of pale or grey skin; the skin may also turn hard and cold. As frostbitten areas warm, they can be extremely painful. Severely frostbitten skin will eventually turn black and slough off.