Training Shih Tzus is difficult. They seduce their owner into forgetting their misdeeds.
Lakeland Terriers know they are too smart. This breed's "big dog in a small package" bravado requires ongoing challenge
Bloodhounds can be trained, but they must be started right away or they'll become stubborn. Bloodhounds can't be untrained.
Rottweilers are people-pleasers, but training them takes time and effort. The breed is trainable, although their stubbornness might make some days harder than others.
Owners find Borzois tough, strong-willed, and independent, making training difficult.
Siberian Huskies are fun. Loyal and energetic. Their energy puts them on this list of hard-to-train dogs.
Old English Sheepdogs are resistant, especially if training becomes repetitious and robotic.
Mastiffs are huge, emotional, and will snore if not trained. Owners must be stern yet kind when training this big breed.