So far, the only thing that i have found that last a very long time and great for dogs to chew on is deer antler. I have been a avid hunter for a long time and Achim snaged ahold of a deer shed I had found. At first I was upset that he was grabbing things off the table, then realized that it was the only thing he was chewing on. Since then I have taken him shed hunting and he will find them all over in places I wouldnt be able to get to. I have found more sheds in the last 2 years than iv ever found on my own. Its a win win. Achim gets chew toys and I figure out where the big deer are. You can go to petco or petsmart and they will charge you 7 to 8 dollars for a 3 inch small peice of antler.