Many breeds considered contenders for the "world's largest" title, despite their ferocious ancestors, are pacifists of the canine kingdom, much preferring cuddling to combat. For this, all dog lovers can be thankful -- if breeds the size of ponies were as aggressive as many miniatures, they'd be extinct. Nonetheless, as the case of a usually laid-back English mastiff named Cromwell illustrates, when appropriate, the protective instincts of a huge dog can still kick in with a vengeance.
World's Tallest Breed
The American Kennel Club says that the Irish wolfhound, with a height of 30 to 34 inches at the shoulder, is the canine world's tallest breed -- although with an average weight of 120 pounds, the Irish wolfhound is far from the heaviest. These sleek, lean and muscular dogs once guarded the castles of royal masters, fought alongside them in battle and brought down wolves and Irish elk on hunts. According to the AKC, the earliest reference to the breed comes from Roman records dating back to 391 A.D. The latter half of the Irish proverb, "Gentle when stroked, fierce when provoked," had more truth to it in centuries gone by, although today's breed still retains its enthusiasm for a good chase.
World's Heaviest Breed
Several breeds of mastiff are recognized by the AKC, but if someone refers to a "mastiff" without qualifiers, they're talking about the Old English mastiff. With a shoulder height of about 30 inches, this dog can tip the scales at more than 200 pounds, making the Old English mastiff the world's heaviest breed. In the days of the Roman empire, ancestors of the mastiff were used as war dogs. Later, farmers valued the breed for its ability to scare off both animal and human predators. Today's mastiff, a gentle soul, also excels as a protector, often by just standing there doing nothing.
Cromwell Kicks Butt
It was a lazy June afternoon in Berwickshire, England, when George Watson, enjoying a relaxing soak in the tub, heard "a scream, a roar and a commotion" coming from his back yard. Throwing a towel around his waist, he raced outside to find his 300-pound mastiff, Cromwell, none too happy. From Cromwell's demeanor and other clues, including a badly torn T-shirt, a lawn mower that had been removed from Watson's shed, and a van being driven by a man naked from the waist up scorching down the driveway, Watson deduced that Cromwell had foiled an attempted burglary. Perhaps even more noteworthy: this behemoth, who could easily have killed or seriously injured the intruder, had used no more force than necessary to stop the crime.
Zeus and Zorba
Sometimes dogs, like kids who grow up to be NBA players, just keep growing until they dwarf their peers. Zeus, a black Great Dane who measures 7 feet 4 inches when standing on his hind legs, is the 2013 Guinness World Record holder for the world's tallest dog. To put this in perspective, as everyone knows, Great Danes are tall -- on average, they measure about 30 inches at the shoulder. Zeus, who lives with his adoring family in Otsego, Michigan, measures 44 inches. Difficult though it may be to imagine a bigger dog, in 1989, a mastiff named Zorba weighed in at 343 pounds and measured more than 8 feet from nose to tail.