Getting a second dog to entertain the first dog is generally a terrible idea. Especially another high-energy dog. They don't entertain each other as much as you would think- instead you're going to have TWO high energy dogs to deal with, twice the training... twice the headache (especially when the first is still a puppy). It sounds like a boredom issue, but another dog is only going to exacerbate the problem. Work on your current dog- the general "rule of thumb" is to only entertain the idea of getting a second when the first is mature and training is down pat.