I would get some Blue Kote to put on it. It's an antiseptic spray that also helps discourage pecking of the wound. I don't know if it disguises it, or how that part works, but I used it a couple of years ago when my own puppy got ahold of some of my chickens. It worked well and the birds healed nicely. I didn't really have room to separate them, so they all stayed with the flock and I didn't have any pecking problems at all.
How did the dog get your chicken? Were the birds free ranging? Does the pup come over on a regular basis? A means of separation might be something to consider, whether that means fencing off the yard or penning the chickens. Remember - if a dog can get to them, so can any number of other predators. Hope your bird turns out OK.