Most pet stores have the bully sticks. There is someone on here who sells them also but for immediate fix run to petsmart, pet quarters, any pet store and look. I have not seen them at walmart though, so pet stores are the answer.
Make sure when the stick gets down to about an inch and a half you throw it away and get another cause he can choke on it if he puts the whole thing in his mouth.
Mine absolutely love bully sticks.....I just do not care to touch em too much