It depends on how big the bone was (is) of course, but if he got it all down then I wouldn't worry too much. The acidity of a dog's stomach is much greater than a humans for this exact purpose (digesting bone). Some dog-foods even contain bits of bone. If a human were to try and eat this particular kind of dog-food then they would have to get their stomachs pumped out.
The dog see's a reflection of him with the bone and thinks it is another dog with another bone.
White and yellow foam or liquid is bile from the dogs stomach. This indicates that they have usually swalled something unpleasant that is causing the upset. The bone was probably not crunched down enough and the stomach is working hard to digest it. It would be better if the object causing the vomiting could come out in the vomit as the only alternative is for it to pass through the rear end. An undigested bone can be very painful as it makes its long journey out!
The Dog and the Bone is one of Aesop's fables
A patient dog eat the fattest bone
A dog fetching a bone is a fine example of a treat. (for the dog)
Given the Dog a Bone was created in 1980.
The "dog and bone" is rhyming slang for "phone". Practical application: "Will ya shuddup, I'm on the dog and bone."
Clavicle bone
Dog Mud Bone
The dog bone is not repairable, simply replace it.
It means your happy just like a 'dog with a bone' to chew on.
Dog and bone is cockney rhyming slang for phone (telephone)