I have known three dogs called Monty. The first, a toy poodle, was short for Montmorency; the second, a cocker spaniel, was short for Montgomery, the name of the house at my school of which his owner was the house master; and the third, a labradoodle, appears to be short for nothing, so I have decided that it is short for Montepulciano, a pleasant Italian red. Incidentally, when FM Lord Montgomery visited my school, he was rather put out to discover that the house was not named after him, but after a former housemaster.