As the old saw says, "It's not the size of the dog in the fight, it's the size of the fight in the dog." Not that the miniature schnauzer is an aggressive bully -- he's not -- but he is, after all, a terrier and bred to terrorize rats and other vermin.
Them's the Rules, Folks
The breed standard for the miniature schnauzer, by AKC rules, is 18 to 20 inches at the shoulder for dogs and 17 to 19 inches for bitches (that's kennel-talk, by the way, not cussin', and is drawing-room proper in dog circles). Anything taller is a standard schnauzer by definition and anything shorter is a runt. Measuring a dog's height at home is a semi-complicated process involving yardsticks, flat surfaces, helpers and pencil marks on the wall, but at a dog show they use a special apparatus to determine whether he's a officially a miniature or not.
How'd He Get that Way?
The miniature schnauzer was bred down in size from the standard schnauzer by crossbreeding with smaller breeds, such as the miniature pinscher and the affenpinscher (all good German dogs, nicht war?). Venturesome breeders may have included others, such as the Pomeranian or even the poodle. These dogs are recognizable in paintings all the way back to the 15th century and were exhibited as miniatures beginning in 1899, but it all came together with recognition as a separate breed in 1926.
Form Follows Function
The standard schnauzer was bred to drive cattle and do general work around the farm, but the miniature has a breed-specific task: pest control. His smaller size lets him pursue this goal in spaces the standard could not possibly enter. He is part of the terrier group and can go to ground as an earthdog with the best of them. He also retains the watchdog spirit of the larger schnauzers and is not afraid to let burglars know whose house it is and who's large and in charge.
Is Miniature the Smallest Schnauzer?
The zwergschnauzer ("dwarf schnauzer" in German, another name for the miniature) is still officially the smallest true breed, but even smaller sizes below the breed standard -- called "toy" or "teacup" -- are popular as portable companions, and it may be only a matter of time before they become a recognized breed. If they do, the schnauzer will be one up on the poodle, which comes in only three sizes.