What do England, the U.S. Marines, Yale University, University of Georgia, and dozens of other schools all have in common? The dog they have all chosen to represent their tough, tenacious characters. That dog? Why, it's the Bulldog, of course!

Sometimes called the English Bulldog or the British Bulldog, the breed originated in England and has a bloody past. It descended from fighting mastiffs that were brought to the British Isles by the Romans and was used in a bloody sport called bullbaiting. Today, however, the Bulldog only slightly resembles his ancestors in appearance. And all of the ferociousness that he exhibited in the bullbaiting pens? Gone for good. Despite his still ferocious appearance, you'd be hard-pressed to find a dog with a sweeter, more loving disposition.

Bulldogs are never mistaken for other breeds of dogs. They are a medium-size dog with a thick-set, low-slung body. Their short-muzzled head is massive and square. They have broad shoulders and chests, with thick, sturdy limbs.

Although Bulldogs are low to the ground, they are wide and muscular. Their broad heads have cheeks that extend to the sides of their eyes, and the skin on their foreheads should have dense wrinkles. A Bulldog has a droopy upper lip and his lower jaw is undershot, meaning that his lower teeth stick out farther than his top teeth. The Bulldog's jaws are massive and strong, intended for latching on to his opponent and holding on.

Bulldogs have round, dark eyes. Their ears are small and thin, folded back like a rose. Their short tails are carried low on their rumps.

The Bulldog's muscular body leads him to have a distinctive gait. Because his stocky legs are set at each corner of his body, he moves with more of a waddle than a walk. It resembles sort of a loose-jointed, shuffling, sideways roll. Because their shoulders are much wider than their rear ends and they have such large heads, it's difficult for the females to whelp puppies without assistance. Most have to have caesarean sections to deliver their puppies, so breeding a Bulldog is an expensive proposition.

Despite cartoon depictions of them as ferocious dogs, today's Bulldogs are bred to be affectionate and kind. They are, indeed, resolute and courageous, but they aren't out to pick a fight. They often have a calm dignity about them when they are mature, and while they are friendly and playful, they can be a bit stubborn and protective of their families. Bulldogs love people. They seek people out for attention and enjoy nothing more than languishing next to their masters, and perhaps snoring while sleeping with their heads in their laps.

Unfortunately, the Bulldog's unique body and head structure makes him prone to health problems, especially respiratory and joint difficulties. They can quickly become overweight if they don't get enough exercise. Too much weight stresses their bodies and may aggravate existing health problems.

The Bulldog is popular dog in the U.S., but he's not for everyone. He's surprisingly heavy for his size, and if you need to pick him up, say to take him to the vet, it can be a challenge. Inside the house, Bulldogs tend to be inactive, preferring to sleep until it's time to eat again. They love children, but don't expect them to spend hours chasing a ball or running with the kids in the backyard. Your Bulldog may engage in such play for a while, but then you'll find him back at your side, content to watch the world go by and look up at you happily with that face that only a mother - or a devoted Bulldog fan - could love.