Editing Greyhound (section)

== Health and physiology ==
[[File:Ghundskeleton.jpg|thumb|Illustration of the Greyhound skeleton]]
A 2024 UK study found a life expectancy of 11.5 years for the breed compared to an average of 12.7 for purebreeds and 12 for [[Mongrel|crossbreeds]].<ref>{{cite journal | last1=McMillan | first1=Kirsten M. | last2=Bielby | first2=Jon | last3=Williams | first3=Carys L. | last4=Upjohn | first4=Melissa M. | last5=Casey | first5=Rachel A. | last6=Christley | first6=Robert M. | title=Longevity of companion dog breeds: those at risk from early death | journal=Scientific Reports | publisher=Springer Science and Business Media LLC | volume=14 | issue=1 | date=2024-02-01 | issn=2045-2322 | doi=10.1038/s41598-023-50458-w | page=531| pmid=38302530 | pmc=10834484 | bibcode=2024NatSR..14..531M }}</ref> A 2005 Swedish study of insurance data found 60% of Greyhounds died by the age of 10, higher than the overall rate of 35% of dogs dying by the age of 10.<ref>{{cite journal | last1=Egenvall | first1=A | last2=Bonnett | first2=Bn | last3=Hedhammar | first3=å | last4=Olson | first4=P | title=Mortality in over 350,000 Insured Swedish Dogs from 1995–2000: II. Breed-Specific Age and Survival Patterns and Relative Risk for Causes of Death | journal=Acta Veterinaria Scandinavica | volume=46 | issue=3 | date=2005-09-30 | pages=121–136 | issn=1751-0147 | pmid=16261925 | pmc=1624818 | doi=10.1186/1751-0147-46-121 | doi-access=free }}</ref>
{{Multiple image
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| footer            = A Greyhound in the extended ''(top)'' phase and the contracted phase of double rotary suspension gallop
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The speed of a Greyhound is due to its light but muscular build, large [[heart]], highest percentage of oxidative–glycolytic [[fast twitch muscle]] fibers (Type IIa) of any breed,<ref>Snow, D.H. and Harris R.C. "Thoroughbreds and Greyhounds: Biochemical Adaptations in Creatures of Nature and of Man" ''Circulation, Respiration, and Metabolism'' Berlin: Springer Verlag 1985</ref><ref>Snow, D.H. "The horse and dog, elite athletes – why and how?" ''Proceedings of the Nutrition Society'' 44 267 1985</ref><ref>{{Cite journal |last1=van Boom |first1=Kathryn M. |last2=Schoeman |first2=Johan P. |last3=Steyl |first3=Johan C. A. |last4=Kohn |first4=Tertius A. |date=2023 |title=Fiber type and metabolic characteristics of skeletal muscle in 16 breeds of domestic dogs |url=https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25207 |journal=The Anatomical Record |language=en |volume=306 |issue=10 |pages=2572–2586 |doi=10.1002/ar.25207 |pmid=36932662 |issn=1932-8486|hdl=2263/92633 |hdl-access=free }}</ref> [[double suspension gallop]], and extreme flexibility of its [[Vertebral column|spine]]. "Double suspension rotary gallop" describes the fastest running gait of the Greyhound in which all four feet are free from the ground in two phases, contracted and extended, during each full stride.<ref>Curtis M Brown. ''Dog Locomotion and Gait Analysis''. Wheat Ridge, Colorado: Hoflin 1986 {{ISBN|0-86667-061-0}}</ref>

The musculature of both hindlimbs constitutes more than 18% of their body mass. The proportion of both forelimbs muscle mass is very similar. The proportion of back musculature is 12% of their body mass.<ref>{{Cite journal |last1=Williams |first1=S. B. |last2=Wilson |first2=A. M. |last3=Rhodes |first3=L. |last4=Andrews |first4=J. |last5=Payne |first5=R. C. |date=2008 |title=Functional anatomy and muscle moment arms of the pelvic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris) |journal=Journal of Anatomy |language=en |volume=213 |issue=4 |pages=361–372 |doi=10.1111/j.1469-7580.2008.00961.x |issn=0021-8782 |pmc=2644771 |pmid=18657259}}</ref><ref>{{Cite journal |last1=Williams |first1=S. B. |last2=Wilson |first2=A. M. |last3=Daynes |first3=J. |last4=Peckham |first4=K. |last5=Payne |first5=R. C. |date=2008 |title=Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris) |journal=Journal of Anatomy |language=en |volume=213 |issue=4 |pages=373–382 |doi=10.1111/j.1469-7580.2008.00962.x |issn=0021-8782 |pmc=2644772 |pmid=19034998}}</ref>

Due to the Greyhound's unique physiology and anatomy, a veterinarian who understands the issues relevant to the breed is generally needed when the dogs need treatment, particularly when [[anesthesia]] is required. Greyhounds cannot metabolize [[barbiturate]]-based anesthesia in the same way that other breeds can because their [[liver]]s have lower amounts of [[oxidative enzyme]]s.<ref>Blythe, Linda, Gannon, James, Craig, A. Morrie, and Fegan, Desmond P. (2007). ''Care of the Racing and Retired Greyhound'', p. 416. American Greyhound Council, Inc., Kansas. {{ISBN|0-9641456-3-4}}.</ref>  Greyhounds demonstrate unusual blood chemistry,<ref>{{Cite journal|title=Clinical pathology of Greyhounds and other sighthounds|first1=S.|last1=Zaldívar-López|first2=L.M.|last2=Marín|first3=M.C.|last3=Iazbik|first4=N.|last4=Westendorf-Stingle|first5=S.|last5=Hensley|first6=C.G.|last6=Couto|date=December 22, 2011|journal=Veterinary Clinical Pathology / American Society for Veterinary Clinical Pathology|volume=40|issue=4|pages=10.1111/j.1939–165X.2011.00360.x|doi=10.1111/j.1939-165X.2011.00360.x|pmid=22092909|pmc=3816276}}</ref> which can be misread by veterinarians not familiar with the breed and can result in an incorrect diagnosis.<ref>[https://www.riversideanimalcare.com/about-us/your-dublin-vet/c-guillermo-couto-dvm-diplomate-acvim-columbus-ohio-veterinarian/greyhounds-really-dogs/Couto Veterinary Consultants ''Are Sighthounds Really Dogs?''], 2017</ref>

Greyhounds are very sensitive to [[insecticide]]s.<ref>Branigan, Cynthia A. (1998). ''Adopting the Racing Greyhound'', p. 99-101. Howell Book House, New York. {{ISBN|0-87605-193-X}}.</ref> Many vets do not recommend the use of [[flea collar]]s or [[Dog flea|flea spray]] on Greyhounds if the product is [[pyrethrin]]-based. Products like [[Imidacloprid|Advantage]], [[Fipronil|Frontline]], [[Lufenuron]], and [[Amitraz]] are safe for use on Greyhounds, however, and are very effective in controlling fleas and [[tick]]s.<ref>Branigan, Cynthia A. (1998). ''Adopting the Racing Greyhound'', p. 101-103. Howell Book House, New York. {{ISBN|0-87605-193-X}}.</ref>

Greyhounds have higher levels of [[red blood cell]]s 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.<ref>Blythe, Linda, Gannon, James, Craig, A. Morrie, and Fegan, Desmond P. (2007). ''Care of the Racing and Retired Greyhound'', p. 82. American Greyhound Council, Inc., Kansas. {{ISBN|0-9641456-3-4}}.</ref> Conversely, Greyhounds have lower levels of [[platelets]] than other breeds.<ref>{{cite web |title=Making Sense of Blood Work in Greyhounds |url=http://www.animalmedicalcentreofmedina.com/library/Greyhound%20Labwork.pdf |access-date=5 Nov 2014 |archive-url=https://web.archive.org/web/20090325034106/http://www.animalmedicalcentreofmedina.com/library/Greyhound%20Labwork.pdf |archive-date=25 March 2009}}</ref>

Delayed [[haemorrhage]] following trauma or routine surgery is more common in Greyhounds, with one study reporting significant haemorrhage in 26% of Greyhounds following routine [[Neutering|gonadectomy]],<ref name="Lara-García 525–533">{{Cite journal|last1=Lara-García|first1=A.|last2=Couto|first2=C. G.|last3=Iazbik|first3=M. C.|last4=Brooks|first4=M. B.|date=May 2008|title=Postoperative bleeding in retired racing greyhounds|url=https://pubmed.ncbi.nlm.nih.gov/18466249|journal=Journal of Veterinary Internal Medicine|volume=22|issue=3|pages=525–533|doi=10.1111/j.1939-1676.2008.0088.x|issn=0891-6640|pmid=18466249}}</ref> compared to 0-2% in other dog breeds.<ref name=":0" /> This is often termed greyhound fibrinolytic syndrome or breed-associated hyperfibrinolysis, where in there is a disorder of the [[Fibrinolysis|fibrinolysis system]] without derangement of the [[Coagulation|primary or secondary coagulation systems]], and is also not related to [[platelet]] count.<ref name=":0" /> In this syndrome there is initial adequate [[hemostasis]] following trauma or routine surgical procedures, however 36–48 hours later the site undergoes inappropriate [[Fibrinolysis|hyperfibrinolysis]].<ref name="Lara-García 525–533"/> This results in delayed bleeding which can result in significant morbidity and mortality.<ref name=":0" /> Standard pre-operative blood work does not identify those at risk<ref name=":0">{{Cite journal|last1=Birkbeck|first1=R.|last2=Humm|first2=K.|last3=Cortellini|first3=S.|date=November 2019|title=A review of hyperfibrinolysis in cats and dogs|url=https://pubmed.ncbi.nlm.nih.gov/31608455|journal=The Journal of Small Animal Practice|volume=60|issue=11|pages=641–655|doi=10.1111/jsap.13068|issn=1748-5827|pmid=31608455|s2cid=204544250}}</ref> It is distinct from common bleeding disorders in other breeds such as [[von Willebrand's disease]], which is uncommon in Greyhounds.<ref>{{Cite journal|last1=Zaldívar-López|first1=S.|last2=Marín|first2=L. M.|last3=Iazbik|first3=M. C.|last4=Westendorf-Stingle|first4=N.|last5=Hensley|first5=S.|last6=Couto|first6=C. G.|date=December 2011|title=Clinical pathology of Greyhounds and other sighthounds|journal=Veterinary Clinical Pathology|volume=40|issue=4|pages=414–425|doi=10.1111/j.1939-165X.2011.00360.x|issn=1939-165X|pmc=3816276|pmid=22092909}}</ref> Although high-quality research data are lacking, it is thought that this condition can be prevented and treated by administering antifibrinolytic medication such as [[tranexamic acid]] via the oral or [[parenteral]] route.<ref>{{Cite journal|last1=Osekavage|first1=Katie E.|last2=Brainard|first2=Benjamin M.|last3=Lane|first3=Selena L.|last4=Almoslem|first4=Mohammed|last5=Arnold|first5=Robert D.|last6=Koenig|first6=Amie|date=October 2018|title=Pharmacokinetics of tranexamic acid in healthy dogs and assessment of its antifibrinolytic properties in canine blood|url=https://pubmed.ncbi.nlm.nih.gov/30256146|journal=American Journal of Veterinary Research|volume=79|issue=10|pages=1057–1063|doi=10.2460/ajvr.79.10.1057|issn=1943-5681|pmid=30256146|s2cid=52823458}}</ref><ref name=":0" /> Intensive care and blood product administration may also be required in severe cases.<ref name=":0" />

Greyhounds do not have undercoats and thus are less likely to trigger dog allergies in humans (they are sometimes incorrectly referred to as "[[hypoallergenic]]"). The lack of an undercoat, coupled with a general lack of body fat, also makes Greyhounds more susceptible to extreme temperatures (both hot and cold); because of this, they must be housed inside.<ref>Blythe, Linda, Gannon, James, Craig, A. Morrie, and Fegan, Desmond P. (2007). ''Care of the Racing and Retired Greyhound'', p. 394. American Greyhound Council, Kansas. {{ISBN|0-9641456-3-4}}.</ref> Some Greyhounds are susceptible to [[Corn (pathology)|corns]] on their paw pads; a variety of methods are used to treat them.<ref>{{Cite web|url=http://www.ngap.org/greyhound-health-corn-y301.html|title=Greyhound Health. Corns in Greyhounds.|website=www.ngap.org|access-date=2019-05-09|archive-date=2018-08-08|archive-url=https://web.archive.org/web/20180808213821/http://www.ngap.org/greyhound-health-corn-y301.html|url-status=dead}}</ref><ref>{{Cite web|url=https://cpd.vettimes.co.uk/cpd-plus/companion-animal/cpd-dermatology/digital-flexor-tenotomy-for-treatment-of-corns-in-dogs|title=Vet Times CPD + Digital flexor tenotomy for treatment of corns in dogs|website=cpd.vettimes.co.uk}}</ref>

[[Thyroxine]] levels in the Greyhound are below the normal reference range for dogs; thyroxine response to [[thyroid-stimulating hormone]] is also lowered. This can impact testing for thyroid disease but it is not a concern for health.<ref>{{cite book |author1-first=J. Catherine |author1-last=Scott-Moncrieff |editor1-last=Feldman | editor1-first=Edward C. | editor2-last=Nelson | editor2-first=Richard W. | editor3-last=Reusch | editor3-first=Claudia | editor4-last=Scott-Moncrieff | editor4-first=J. Catharine |title=Canine and feline endocrinology |date=2015 |publisher=Elsevier Saunders |location=St. Louis, Missouri |isbn=978-1-4557-4456-5 |edition=Fourth |url=http://www.sciencedirect.com/book/9781455744565/canine-and-feline-endocrinology |chapter=Hypothyroidism| publication-place=St. Louis, Missouri | pages=102}}</ref>