Giant Schnauzer... The very biggest of the 3 Schnauzer dog breeds, the other 2 breeds being the miniature schnauzer and standard schnauzer. These big dogs are strong-willed and an amazing guard dog! Children 12 years and older are most appropriate for this big and active dog breed. This dog is a less than average shedder, but might take some time to be groomed. Intelligent, but can be tough to train for an inexperienced trainer.