My dogs have been chewing on antlers since i was a child.. my old dog used to find them in the woods when we were camping, he had at least 10, and now that he has passed on Asia inherited them.. so 10 years later and they are still lasting chew toys! It was cute, he would grab the middle of the antler and the long parts would wrap around his head.
Antlers are supposed to be very healthy for chewing. There are several companies that are making supplements from the velvet as well. Check out this site, they even have a product for dogs! http://www.velvetenergy.com/composition.php I haven't bought any for my dogs but maybe I will for Christmas. My dogs aren't crazy about nylabones and bully sticks don't last very long at my house. Thanks for sharing the link!