Have you ever seen a dog that looks like it’s wearing a clumpy sweater? The wind blows over them but, aside from a few scraggly bits, the hair remains undisturbed. This is because the coat has become so thoroughly tangled that the tats have become mats: thick bunches of hair resembling dreadlocks. They might be isolated to one or two spots, or cover a dog’s entire body. A lot of dog owners think this impenetrable wall of hair will keep Fido warm in the winter. They’re wrong. I’ve been a professional dog groomer for a number of years and I’ve groomed thousands of our four-legged friends. Over time, something has…