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Greyhound Running on grass

The American Kennel Club recognizes 184 dog breeds, and each was originally created for a reason whether it was to help put food on the table, guard herds, control vermin, or provide companionship. Most of these breeds are uniquely suited to do their job, and what follows is one such dog: Behold the perfect canine running machine, the Greyhound.

She has an “S-shaped body” that allows her to master the double suspension rotary gallop, a four-time gait (and the only gait) in which a dog is unsupported by legs when fully extended.

As she prepares to run, she shifts her weight to both rear legs and pushes off, launching herself forward, front legs fully extended and reaching for ground still well ahead of her. As her rear feet prepare to grab more land, her flexible back folds into the shape of the letter “c” enabling her knees to “say hello” to her ribs.

Rear paws overtake the front ones pulling even more real estate beneath her. Outstretched front paws are ready to absorb the weight of her landing before she repeats the contracted and extended phases of her running motion. In the moments before she “touches down,” all four feet are off the ground. Metaphorically speaking, she is a bird, airborne and unsupported by planet Earth. Her feet will touch the ground only 25 percent of the time she is running at the 45 miles-per-hour she’s capable of reaching in a few strides.

Long narrow, hare-like feet give her maximum leverage, and because they are well knuckled and compact, she gets better traction and requires less energy to lift them. As her weight shifts forward, the ball of her foot becomes a fulcrum and her pasterns (knees) and toes become a lever, while thickly padded paws act as shock absorbers.

A skinny “waistline” allows her to flex her back from an outstretched position to an arched one that brings the southern half of her body into her northern hemisphere. She’d be unable do this if the most flexible point on her back wasn’t over her loin area called the “tuck up.” It’s what helps this leggy breed be breathtakingly fast, but still be able to curl up and take a nap in a small cat bed.

greyhounds playing

She has a narrow, aerodynamic head set on a long, muscular neck that blends smoothly into her withers, and this gives her balance. At the other end is a long, thin tail she uses like a rudder while running, and (some experts believe), to create drag when cornering so she can slow down without breaking stride and still accelerate onto the straight away.

Her “model” includes extra features: She has light bones and a body weight that is approximately 16 percent fat, less than half the amount of other dogs her size, and yet her powerful muscles have the highest percentage of fast-twitch muscle of any breed. Wide nostrils allow her to take in as much air as possible, and small rose ears can be aerodynamically folded over so as to reduce drag. Her stereoscopic eyes can track prey from a mile away – but wait, there’s more. Lift her “hood” and prepare to be dazzled.

Her deep chest houses extraordinarily efficient lungs and the largest heart of any breed. When she’s running, her heart can beat five times a second enabling her to circulate her entire blood volume four to five times during the course of a 30-second sprint.

She has approximately 4 percent more blood than other dogs, and if she’s racing professionally, she has the highest-packed cell volume of any dog, some 60 percent compared to 35 percent. She has significantly more oxygen-carrying red blood cells that she can move quickly from her lungs to her muscles – all of which, incidentally, also makes a majority of the breed highly valued as canine universal blood donors.

Around 70 percent of the time she’s running is spent in the air, and this makes her the second fastest animal on earth. With a constant stride frequency of 3.5 strides-per-second across all speeds, only the cheetah is faster.

She is a speed demon, but with her people, she is quiet, loving, and gentle. They describe her as a “45 mile-per-hour couch potato.”

She is the perfect canine running machine, but you know her as the Greyhound.

Learn more about the Greyhound, a breed described as independent, gentle, and noble:


Susi Szeremy has been a Puli fancier since 1978 and writes professionally for several dog publications as well as for Westminster Kennel Club’s social media presence. She created National Purebred Dog Day and administers its official Facebook page.