A Spanner Dog refers to those of the human species that are well below the average intelligence. A Spanner Dog will resemble a mouthbreathing, dough banging idiot of a bloke. Common traits include vacant looks, low levels of comprehension, mouth agape, drooling, possible lazy eye.
My friendsboyfriend is on a spank sabbatical, because he was waxing his own carrot too much, and became desinsitized , no longer able to perform intercourse with his girlfriend.