any of three breeds of dogs (dog)—the standard, miniature, and giant schnauzers—developed in Germany and named for their distinctive “mustache.” The standard, or medium-sized, schnauzer is the stock from which the other two breeds were derived. It is shown in paintings and in a statue dating from the 15th and 16th centuries. Originally a guard dog and ratter, it was highly valued for its intelligence and courage. A robust dog, it is characterized by a blunt, heavily whiskered muzzle, a squared body, and a hard, wiry coat of black or salt-and-pepper. The standard schnauzer is most popular as a guard and companion; it has been used as a dispatch carrier, Red Cross dog, and police dog. It stands 17 to 20 inches (43 to 51 cm) high.

The giant schnauzer, largest and most recent of the three breeds, was developed by Bavarian cattlemen who wanted a cattle dog like the standard schnauzer but larger. To produce such a dog, the standard schnauzer was crossed with various working dogs and, later, with the black Great Dane. The giant schnauzer, like the others, is a robust dog with a wiry coat. It stands 23.5 to 27.5 inches (60 to 70 cm) high and is salt-and-pepper, black, or black-and-tan in colour. Originally a cattle dog, it was later used as a butcher's dog and a brewery guard. Since the beginning of the 19th century, it has been used extensively in German police work.

The standard and giant schnauzers are placed in the working-dog group of the American Kennel Club; the miniature is classed as a terrier.