Stacker highlights the 50 biggest dog breeds, according to the American Kennel Club, from the Irish setter to the mastiff.

Why origins matter: Many guard dogs were bred for centuries to protect livestock, property, or people, shaping their instincts and behaviors today. Key breed traits: From the aloof Tibetan Mastiff to ...

Anger isn’t a symptom of bipolar disorder, but irritability and restlessness during manic or hypomanic episodes may be perceived as anger by others. Mood stabilizers like lithium can cause side ...