It would be a nice addition. Although personally I'd rather see a wagon instead of a cart.

For the cart it may be a better idea to hitch a wolf in front of it.

Something I was thinking about, is the ability to have a Lox follow you, or lead it, while it has something like saddle bags or a carrier rack stretch at its back. One making it easier to transport items, while riding the lox, while the other requires walking, but is able to transport more goods.

Thorin :)