posted: 05/15/12
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One of the few ways in which domestic dogs have changed dramatically from their wolf ancestors is seen in the shape of their skulls. Domestication and the subsequent breeding for specific, desirable head shapes have resulted in three basic skull types.

Dolichocephalic skull

Dogs bred for exceptional sight, such as Salukis and greyhounds, sport slightly elongated versions of the wolf's cranium. Called "dolichocephalic," this skull shape features a long and relatively narrow snout.

Mesocephalic skull

In many scent hounds and pointers, the wolf's skull has been reduced in length. These "mesocephalic" skulls feature somewhat broader snouts and larger nasal chambers that help improve scenting abilities.

Brachycephalic skull

Boxers, bulldogs and some other so-called "fighting" dogs possess a much shorter snout. Called "brachycephalic," this compact skull type is thought to result in more powerful jaws — and in extreme versions, such as the pug and the bulldog — a variety of health problems. Along with sometimes having painfully overcrowded teeth, dogs with reduced snouts cannot cool themselves properly by evaporating water through their nasal cavities, as most canids do. These pets are at particular risk of overheating in warm weather.

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