In the wild, the favorite parts that wolves eat is the internal organs like the kidneys, liver, heart. All of them should work to make dog treats with. The high gristle portions such as the brisket would also be a good one.
Deer: Front forelegs cut into chunks, chopped liver (soaked), chopped heart, and any other misc trimmings that are too small to cut the silver off for burger. I simmer in an XL stock pot for about 4-6 hours and remove after the silver gets gummy - want to make sure I cook it enough so nothing gets caught in my dog's GI track. Most important is avoiding large pieces of elastic connective tissue near the sternum and joints as this can can easily become an obstruction. Put into quart Ziploc freezer bags and freeze, then move one bag at a time to the fridge to feed to the dog over a 4-day period. She loves it! Yield of maybe 7-8 lbs off a 130 lb deer.
I take everything outside of the alimentary canal and everything that isn't going to be eaten by me or my wife gets made into dog food. Trachea and neck tendons on big animals like elk are great treats for the pooch.