I haven't used dog fur, but I have heard of people who have. When you cut a chunk of fur off a hide (or a living animal) the hair is all approximately the same length and going the same direction. When you brush out or pick up a clump of shed fur, it's just a ball of random hair going every which way. You could probably use it if you comb out the under-fur and run the guard hairs through a hair stacker to orient them and make them even length.