Almost any animal fur is good for felting. Using your own dog's hair to make a felted coat for him is ideal. You can't get a better color match!
However, getting your dogs hair can be tricky. Dog's don't naturally take to being groomed. My main tips for DIY dog grooming
Wash your dog with soap or shampoo before grooming and dry him completely.
Let your dog get used to the grooming shears over a couple days. Show him the shears, turn them on, and give him a treat. Repeat this until he allows you "access" to his fur.
Always shave in the direction of hair growth
Hold your dog with one arm if necessary while shaving with the other
I found the best felting hair was from my dog's legs and belly. It was silkier and finer than anywhere else. Focus on those parts.
Put the hair in a bag and save for later.