This is a very quick but EXTREMLY useful creation made by me. I haven't researched to see if this is original, but I thought of this quickly.

Basically it is a chest mine cart riding a dog. Since it is attached to the dog, it stays with the dog. All you need to do is tame the dog. If he bugs out, tame him and travel away to let him teleport, which fixes him. After you tame him, you might also have to punch him to fully fix him.