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Home / Equine Research Bank / Animals (Basel) / A Comparative Neuro-Histological Assessment of Gluteal Skin ...
Animals : an open access journal from MDPI2020; 10(11); 2094; doi: 10.3390/ani10112094

A Comparative Neuro-Histological Assessment of Gluteal Skin Thickness and Cutaneous Nociceptor Distribution in Horses and Humans.

Abstract: The current project aims to build on knowledge of the nociceptive capability of equine skin to detect superficial acute pain, particularly in comparison to human skin. Post-mortem samples of gluteal skin were taken from men ( = 5) and women ( = 5), thoroughbreds and thoroughbred types (mares, = 11; geldings, = 9). Only sections that contained epidermis and dermis through to the hypodermis were analysed. Epidermal depth, dermal depth and epidermal nerve counts were conducted by a veterinary pathologist. The results revealed no significant difference between the epidermal nerve counts of humans and horses ( = 0.051, = 0.960). There were no significant differences between epidermal thickness of humans (26.8 µm) and horses (31.6 µm) for reference (left side) samples ( = 0.117, = 0.908). The human dermis was significantly thinner than the horse dermis ( = -2.946, = 0.007). Epidermal samples were thicker on the right than on the left, but only significantly so for horses ( = 2.291, = 0.023), not for humans ( = 0.694, = 0.489). The thicker collagenous dermis of horse skin may afford some resilience versus external mechanical trauma, though as this is below the pain-detecting nerve endings, it is not considered protective from external cutaneous pain. The superficial pain-sensitive epidermal layer of horse skin is as richly innervated and is of equivalent thickness as human skin, demonstrating that humans and horses have the equivalent basic anatomic structures to detect cutaneous pain. This finding challenges assumptions about the physical capacity of horses to feel pain particularly in comparison to humans, and presents physical evidence to inform the discussion and debate regarding the ethics of whipping horses.
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Publication Date: 2020-11-11 PubMed ID: 33187204PubMed Central: PMC7696388DOI: 10.3390/ani10112094Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research aimed to compare the skin thickness and distribution of pain receptors in the skin of both humans and horses. The findings show that these superficial characteristics are equivalent in both species, challenging beliefs about horses’ capacity to experience pain.

Methodology

  • The researchers used post-mortem skin samples from both humans and horses for the study. The human samples were taken from five men and five women, while the horse samples were taken from thoroughbred mares and geldings, 11 and 9 each respectively.
  • Only those skin sections were analysed that contained all three layers – the outermost epidermis, the middle dermis, and the innermost hypodermis.
  • The study assessed the depth of the epidermal and dermal layers, and the number of nerves in the epidermal layer.

Results

  • The study found no significant difference in the number of nerves in the epidermal layer of human and horse’s skins.
  • There was no significant difference in the thickness of the epidermal layer between humans and horses. However, the dermis layer in humans was significantly thinner than in horses.
  • In horses, the right side epidermal layer was significantly thicker than the left, a distinction that did not appear in humans.

Implications

  • The equivalent thickness and nerve density in horse skin to human skin implies that horses have similar capacities to sense superficial pain.
  • The thicker dermis layer in horses may offer resilience against external forces but isn’t likely to provide significant protection against superficial skin pain.
  • The findings provide evidence towards the discussion about the ethics of using whips on horses, suggesting that the resulting pain could be similar to what a human would feel under similar conditions.

Cite This Article

APA
Tong L, Stewart M, Johnson I, Appleyard R, Wilson B, James O, Johnson C, McGreevy P. (2020). A Comparative Neuro-Histological Assessment of Gluteal Skin Thickness and Cutaneous Nociceptor Distribution in Horses and Humans. Animals (Basel), 10(11), 2094. https://doi.org/10.3390/ani10112094

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 10
Issue: 11
PII: 2094

Researcher Affiliations

Tong, Lydia
  • Taronga Conservation Society Australia, Mosman, Sydney, NSW 2088, Australia.
Stewart, Melinda
  • Starling Scientific, Pearl Beach, NSW 2256, Australia.
Johnson, Ian
  • Faculty of Medicine, Health and Human Sciences, Macquarie University, Sidney, NSW 2109, Australia.
Appleyard, Richard
  • Faculty of Medicine, Health and Human Sciences, Macquarie University, Sidney, NSW 2109, Australia.
Wilson, Bethany
  • Sydney School of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia.
James, Olivia
  • Australian Veterinary Equine Dentistry, 27 Bellevue Terrace, Clayfield, QLD 4011, Australia.
Johnson, Craig
  • School of Veterinary Science, Tāwharau Ora, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
McGreevy, Paul
  • Sydney School of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia.

Grant Funding

  • . / RSPCA Australia

Conflict of Interest Statement

The authors declare no conflict of interest.

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Citations

This article has been cited 2 times.
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