According to American Kennel Club's conformation standards, the Irish wolfhound is the tallest dog breed, but several other breeds recognized by the AKC can measure almost as big. In fact, the tallest dog on record was a Great Dane, a breed recognized as one of the giants of the dog world.
When standing on their hind legs, the long-legged wolfhounds can comfortably rest their front paws on a man's shoulders. A full-grown male Irish wolfhound can stand as tall as 34 inches at the shoulder and must not be shorter than 32 inches. Males must weigh a minimum of 120 pounds, and many tip the scales at up to 180 pounds. Female wolfhounds must be at least 30 inches tall and weigh at least 105 pounds, though most weigh 115 to 140 pounds.
The tallest dog on record, a Great Dane named Giant George, stood 43 inches at the shoulder. The AKC standards dictate that Great Dane females be at least 28 inches tall, but over 30 inches is preferred. Likewise, males must be at least 30 inches, but over 32 inches is preferred. Another extremely tall dog breed is the Scottish Deerhound, whose height is between 28 and 32 inches, and who weighs 75 to 110 pounds. In addition, the heavyweight mastiff is generally 27 to 30 inches or more and can weigh more than 200 pounds.