The Schnauzer is a popular German dog breed, that comes in three sizes, miniature, standard and giant. All three are recognized as separate breeds by majority of kennel clubs, but they are closely related together, as the miniature and giant Schnauzers are descendants of the original and oldest standard Schnauzer.
And indeed, the size is not the only difference in these dogs. Since they all have slightly different ancestry, they also have slightly different temperament. The Miniature Schnauzer was most likely developeded by crossing Standard Schnauzer to Affenspinscher, Miniature Poodle, Miniature Pinscher or to Pomeranian and the Giant Schnauzer was most likely developeded by crossing the Standard Schnauzer with Great Danes, German Shepherds, Rottweilers, Dobermans, Boxers and Bouvier des Flandres.
The typical temperament of the Standard Schnauzer is described as extemely intelligent, alert, lively, quite playful, kind of independent and strong willed. It is a great choice for guarding, but it also has higher prey drive, as it was used for a long time as vermin hunter. Very often, they are described as dogs with human brain. They are always thinking and it is natural born explorer. They are very curious. They have deep instinctual roots as a guard dogs and vocal dogs and they will most likely bark on any strangers approaching your home. Even though all the Schnauzers are kind of independent, they are relatively easy to train and thanks to their intelligence, they will learn all the basic commands easily.
It is true, that the Miniature and Giant Schnauzer share very similar temperament with the standard Schnauzer, but it is not identical. Lets start with the Miniature Schnauzer.
And the Miniature Schnauzer is described as little bit more affectionate dog, with less prey drive. They are still good alert watchdogs, but they should not bark that much as the standard Schnauzer. Because of their size, they have lower exercise needs, but it is still an active dog. They are probably best to live with kids and they are much more biddable and companionable. It is also very inquisitive and spunky breed.
And what about the Giant Schnauzer? Well, all Schnauzers are good guard dogs, but the Giant Schnauzer is above them. It is extremely strong breed with very smart, independent and protective nature. This Schnauzer, unlike the Miniature one, is not the best choice for novice dog owners. They have natural inclination to protect its people. But they are absolutely loyal and very friendly towards its own family. If you want your Giant Schnauzer to be okay with other dogs or other pets, early proper socialization is absolutely needed, but that can be said about all the Schnauzers. It is also very active dog breed, they need a lot of daily excercise to stay healthy and happy. It is very bold and courageous, rambunctious and reliable dog breed.
So now you know what is the temperament of each Schnauzer breed. And what about the differences in appearance? Well, the obvious one is their size. You can see the size differences on the screen right now. And the size differences are quite huge, there is a massive difference between the giant and miniature Schnauzer. The second difference is in the coat and color. Again, you can see the color possibilities for each Schnauzer breed on the screen. They all typically have medium to long non shedding coat. The Giant Schnauzer is slight exception, as they can have shorter coat as well.