Dog House is a card added in Beta 7.1. Previous Versions can be found here.
Dog House is a decent early to mid-game card with moderate stats and an ability that functions identical to an earlier version of Cloning: Adding an exact copy of a monster that's in your hand to your hand. However, in this case, the use is limited to Dogs.
This can be used in multiple ways. Since you will be increasing the amount of Dogs in your hand (as Dog House isn't one itself), this will improve the effects Bone Painting and Sand Dog.