Abstract：
BACKGROUND: Parasympathetic tone activity (PTA) in response to nociceptive stimulus in conscious non-sedated horses is unknown.
OBJECTIVE: Study PTA, heart rate (HR), and horse grimace scale (HGS) at rest and during mechanical nociceptive stimulation.
METHODS: Ninety healthy young adult horses (females, males): 30 each of Friesians, Quarter Horses, and Warmbloods.
METHODS: Prospective control study. The study consisted of habituation to equipment (Day 1), baseline recordings (Days 2 and 3), and nociceptive testing applying mild pressure to the metacarpus (Day 4). Parasympathetic tone, HR, and HGS were recorded simultaneously on Days 2 to 4. Each study lasted 30 minutes and was done in triplicate at 3 different time points per day.
RESULTS: Baseline PTA was not different among breeds. It decreased in Warmbloods and Quarter Horses during placement of the stimulus device without stimulation (P < .01). A significant decrease in PTA (P < .001) occurred during nociceptive stimulus (marked in Quarter Horses, intermediate in Warmbloods, and mild in Friesians). Heart rate and HGS increased significantly (P < .001) during the stimulus in all breeds but returned to baseline poststimulation. Friesians required higher pressure (P < .05) to elicit an aversive response to the stimulus.
CONCLUSIONS: Horses\' PTA, HR, and HGS change in response to a mild mechanical nociceptive stimulus with Friesians showing less variation. Stress induced a decrease in PTA in Quarter Horses and Warmbloods but not in Friesians. Friesians appeared to be more tolerant to pain based on PTA, HR, and HGS findings compared with other breeds.
OBJECTIVE: Study PTA, heart rate (HR), and horse grimace scale (HGS) at rest and during mechanical nociceptive stimulation.
METHODS: Ninety healthy young adult horses (females, males): 30 each of Friesians, Quarter Horses, and Warmbloods.
METHODS: Prospective control study. The study consisted of habituation to equipment (Day 1), baseline recordings (Days 2 and 3), and nociceptive testing applying mild pressure to the metacarpus (Day 4). Parasympathetic tone, HR, and HGS were recorded simultaneously on Days 2 to 4. Each study lasted 30 minutes and was done in triplicate at 3 different time points per day.
RESULTS: Baseline PTA was not different among breeds. It decreased in Warmbloods and Quarter Horses during placement of the stimulus device without stimulation (P < .01). A significant decrease in PTA (P < .001) occurred during nociceptive stimulus (marked in Quarter Horses, intermediate in Warmbloods, and mild in Friesians). Heart rate and HGS increased significantly (P < .001) during the stimulus in all breeds but returned to baseline poststimulation. Friesians required higher pressure (P < .05) to elicit an aversive response to the stimulus.
CONCLUSIONS: Horses\' PTA, HR, and HGS change in response to a mild mechanical nociceptive stimulus with Friesians showing less variation. Stress induced a decrease in PTA in Quarter Horses and Warmbloods but not in Friesians. Friesians appeared to be more tolerant to pain based on PTA, HR, and HGS findings compared with other breeds.
摘要：
背景：在有意识的非镇静马中响应伤害性刺激的副交感神经紧张活动（PTA）是未知的。
目的：研究PTA，心率(HR),和休息时和机械伤害性刺激期间的马鬼脸量表（HGS）。
方法：90匹健康成年马（雌性，男性）：每个弗里西亚人30人，四分之一马,和温暖的血液。
方法：前瞻性对照研究。该研究包括对设备的习惯（第1天），基线记录（第2天和第3天），和对掌骨施加轻微压力的伤害性测试(第4天)。副交感神经张力，HR,和HGS在第2至4天同时记录。每个研究持续30分钟,并且在每天3个不同的时间点一式三份地进行。
结果：各品种间的基线PTA没有差异。在没有刺激的情况下放置刺激装置期间,它在Warmbloods和四分之一马中降低(P<.01)。PTA（P<.001）的显着下降发生在伤害性刺激期间（以四分之一马，在温暖的血液中间，在Friesian中温和）。所有品种在刺激期间心率和HGS均显着增加（P<.001），但在刺激后恢复到基线。Friesian需要更高的压力（P<0.05）来引起对刺激的厌恶反应。
结论：马\'PTA，HR,和HGS响应于轻度机械伤害性刺激而变化，而Friesian则表现出较小的变化。压力导致四分之一马和温暖的血液中PTA的减少，但在Friesian中则没有。根据PTA，Friesians似乎对疼痛更宽容，HR,和HGS的发现与其他品种相比。
目的：研究PTA，心率(HR),和休息时和机械伤害性刺激期间的马鬼脸量表（HGS）。
方法：90匹健康成年马（雌性，男性）：每个弗里西亚人30人，四分之一马,和温暖的血液。
方法：前瞻性对照研究。该研究包括对设备的习惯（第1天），基线记录（第2天和第3天），和对掌骨施加轻微压力的伤害性测试(第4天)。副交感神经张力，HR,和HGS在第2至4天同时记录。每个研究持续30分钟,并且在每天3个不同的时间点一式三份地进行。
结果：各品种间的基线PTA没有差异。在没有刺激的情况下放置刺激装置期间,它在Warmbloods和四分之一马中降低(P<.01)。PTA（P<.001）的显着下降发生在伤害性刺激期间（以四分之一马，在温暖的血液中间，在Friesian中温和）。所有品种在刺激期间心率和HGS均显着增加（P<.001），但在刺激后恢复到基线。Friesian需要更高的压力（P<0.05）来引起对刺激的厌恶反应。
结论：马\'PTA，HR,和HGS响应于轻度机械伤害性刺激而变化，而Friesian则表现出较小的变化。压力导致四分之一马和温暖的血液中PTA的减少，但在Friesian中则没有。根据PTA，Friesians似乎对疼痛更宽容，HR,和HGS的发现与其他品种相比。
