We took Jaida out for a country walk and she rolled in a deer carcaus. Here's a recipe our vet gave us. Worked wonders for us, hope it works for you.
In a large container, a sink or a tub; mix 1 quart hydrogen peroxide, ¼ baking soda, 1-2 tablespoons of dish soap. Now carefully sponge this over the offensive areas on the dog and be very cautious to not get any of the liquid to the dog's eyes. Let it soak for 5 minutes or more and then rinse it off and now shampoo your dog with his regular mild shampoo and rinse again.