The more types of bones and bone stuffing you have, the easier it will be for you to encourage your small dog to chew bones. Choose natural bones of multiple sizes. You may want to avoid dense, weight bearing bones from large animals, as there is some evidence that these can wear down your dog’s teeth. Rawhide of various flavors are great. Choose some rawhide bones that are much bigger than it seems your dog would need. These provide angles and weight to work against, that can entice picky chewers or dogs prone to chewing on undesirable things.
Choose some bones that can be stuffed with treats or fillings. Trying to get to the filling will provide a natural motivation for your small dog to chew. Provide some different textures and structures in chewing materials, like antlers and horns. Try large dog teething toys to provide some interesting texture in plastic chews.
Motivating your small dog to chew a bone requires some patience and a willingness to experiment. Some dogs seem more motivated to chew after exercise, so try taking your dog for a brisk walk before offering a bone. Heating or cooling a bone can make it much more appealing to some dogs. Check that the bones and possible fillings that you are using are safe to heat or cool and try adding these variables to entice the picky dog
Chewing is as much psychological for a dog as it is about food. A dog who is really enjoying a bone will settle into a methodical chewing that seems almost meditative. Throughout the training process, keep in mind a positive attitude that will encourage your dog to seek stress relief as well, through the natural behavior of chewing a bone.