Try these. They last forever. My dogs love them. They don't chip unless they are thin at the end. I buy them locally so I can see how thick the ends are. I've ran these over with a lawnmower and barely put a dent in them.
Tried antlers. Mine really wouldn't play with them. I have a Goldie that rips the tops off Kongs and 3 others that are destructive with any toy I give them. These were a lifesaver.