Greyhound

Health and Physiology
Greyhounds are typically a healthy and long-lived breed, and hereditary illness is rare. Some greyhounds have been known to develop esophageal achalasia, bloat (gastric torsion), and osteosarcoma. Because the greyhound's lean physique makes it ill-suited to sleeping on hard surfaces, owners of companion greyhounds generally provide soft bedding; without bedding, greyhounds are prone to develop painful skin sores. The typical greyhound lifespan is 10 to 13 years.

Due to the unique physiology and anatomy of greyhounds, a veterinarian who understands the issues relevant to the breed is generally needed when the dogs need treatment, particularly when anaesthesia is required. Greyhounds cannot metabolize barbiturate-based anesthesia as other breeds can because they have lower amounts of oxidative enzymes in their livers. Greyhounds demonstrate unusual blood chemistry, which can be misread by veterinarians not familiar with the breed; this can result in an incorrect diagnosis.

Greyhounds have higher levels of red blood cells than other breeds. Since red blood cells carry oxygen to the muscles, this higher level allows the hound to move larger quantities of oxygen faster from the lungs to the muscles. Greyhounds have lower levels of platelets than other breeds. Veterinary blood services often use greyhounds as universal blood donors.

History
The breed's origin is romantically reputed to be connected to ancient Egypt, where depictions of smooth-coated sighthound types have been found which are typical of Saluki (Persian Greyhound) or Sloughi (tombs at Beni Hassan circa 2000BC). However, analyses of DNA reported in 2004 suggest that the Greyhound is not closely related to these Oriental breeds, but is a close relative to herding dogs. Historical literature on the first sighthound in Europe (Arrian), the vertragus, the probable antecedent of the Greyhound, suggests that the origin is with the ancient Celts from Eastern Europe or Eurasia. All modern, purebred pedigree Greyhounds, are derived from the greyhound stock recorded and registered, firstly in the private 18th century then public 19th century studbooks, which ultimately were registered with Coursing, Racing, and Kennel Club authorities of the United Kingdom.

Historically, these sighthounds were used primarily for hunting in the open where their keen eyesight is valuable. It is believed that they (or at least similarly-named dogs) were introduced to the area now known as the United Kingdom in the 5th and 6th century BC from Celtic mainland Europe although the Picts and other hunter gatherer tribes of the Northern area (now known as Scotland) were believed to have had large hounds similar to that of the Deerhound before the 6th century BC.

The name "greyhound" is generally believed to come from the Old English grighund. "Hund" is the antecedent of the modern "hound", but the meaning of "grig" is undetermined, other than in reference to dogs in Old English and Norse. Its origin does not appear to have any common root with the modern word "grey" for color, and indeed the greyhound is seen with a wide variety of coat colors. It is known that in England during the medieval period, lords and royalty keen to own greyhounds for sport, requested they be bred to color variants that made them easier to view and identify in pursuit of their quarry. The lighter colors, patch-like markings and white appeared in the breed that was once ordinarily grey in color. The greyhound is the only dog mentioned by name in the Bible; the King James version names the Greyhound as one of the four things stately in the Proverbs. However, in the modern version of the Bible this has been changed to strutting rooster, which appears to be a more correct translation of the Hebrew term זַרְזִיר (zarzir).

According to Pokorny the English name "greyhound" does not mean "gray dog/hound", but simply "fair dog". Subsequent words have been derived from the Proto-Indo-European root *g'her- 'shine, twinkle': English gray, Old High German gris 'grey, old', Old Icelandic griss 'piglet, pig', Old Icelandic gryja 'to dawn', gryjandi 'morning twilight', Old Irish grian 'sun', Old Church Slavonic zorja 'morning twilight, brightness'. The common sense of these words is 'to shine; bright'.