If you’re considering an extra big or small breed of dog, keep in mind that training either will come with a special set of challenges.
Big breeds like Saint Bernards often exhibit puppy-like behavior longer than small or medium sized breeds such as a Brittany. Plus, the large breed puppies are often the least coordinated; their clumsy movement correlates directly to their rapid growth. Large breeds, after all, have more growing to do in proportion to smaller breeds. Besides, a Irish Wolfhound will likely double his size between class sessions! No wonder the puppy trips over his own paws trying to coordinate his growing limb movement.
What about specific exercise challenges? Well, don’t expect high points for speed; a Great Dane pup typically can’t coordinate his rapidly-growing limbs for a fast recall. Many big breed pups, however, are renowned for a relaxed disposition and will excel in the down-stay exercise… at least in comparison to the antsy high-energy sporting breeds around them (we’re finger pointing here at the Irish Setter!).
When it comes to housetraining, small and large dogs operate physiologically alike, but size may contribute to the difficulty of housetraining. So yes, tiny dogs are often more difficult to train, but for no fault of their own. After all, it’s more obvious to the owner when a large breed puppy prepares to eliminate than a small dog. Besides, we often don’t see a small dog’s accident because of the tiny amount of urine.
Translated, that means while an unsupervised Yorkshire Terrier puppy needs most of a day to destroy your couch, a Bullmastiff can accomplish the destruction in mere minutes.