Tong Lydia, Stewart Melinda, Johnson Ian, Appleyard Richard, Wilson Bethany, James Olivia, Johnson Craig, McGreevy Paul
Taronga Conservation Society Australia, Mosman, Sydney, NSW 2088, Australia.
Starling Scientific, Pearl Beach, NSW 2256, Australia.
Animals (Basel). 2020 Nov 11;10(11):2094. doi: 10.3390/ani10112094.
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.
当前项目旨在基于对马皮肤伤害感受能力的了解,以检测浅表急性疼痛,特别是与人类皮肤进行比较。从男性(n = 5)和女性(n = 5)、纯种马和纯种类型(母马,n = 11;阉马,n = 9)身上采集臀肌皮肤的尸检样本。仅分析包含表皮、真皮直至皮下组织的切片。表皮深度、真皮深度和表皮神经计数由兽医病理学家进行。结果显示,人类和马的表皮神经计数之间无显著差异(P = 0.051,df = 0.960)。参考(左侧)样本中,人类(26.8 µm)和马(31.6 µm)的表皮厚度无显著差异(P = 0.117,df = 0.908)。人类真皮明显比马真皮薄(P = -2.946,df = 0.007)。表皮样本右侧比左侧厚,但仅马的情况显著(P = 2.291,df = 0.023),人类则不然(P = 0.694,df = 0.489)。马皮肤较厚的胶原性真皮可能对外部机械创伤具有一定弹性,不过由于这位于疼痛检测神经末梢下方,所以不认为其能保护免受外部皮肤疼痛。马皮肤浅表疼痛敏感的表皮层神经支配丰富,厚度与人类皮肤相当,表明人类和马具有检测皮肤疼痛的同等基本解剖结构。这一发现挑战了关于马感受疼痛的身体能力的假设,特别是与人类相比,并提供了实物证据,为关于鞭打马的伦理问题的讨论和辩论提供参考。