It could be a number of reasons. Fleas is the first thing that comes to mind. Stress will do it too. Or if the dogs anal glands are impacted that will do it too. Unfortunatly that last one requires a vet.
Get the dog some good chew toys. Dogs need to chew.
Yes, A dog could vomet after eating a chew toy
rice
No, but chow is.
A Bone
You will poison
A Bone
It's awful to imagine it but if a dog is in enough pain and distress it might be driven to chew off a toe.
No They Will Die.
being friendly
because they itch
Some alternative chew toys to dog bones involve some of the following: Nylabone Durable Dental Dinosaur Chew Toy, the Kong Extreme Dog Boy, and Pet Stages Soft Toss Ring.