Nociceptive pain and anxiety in equines: Physiological and behavioral alterations

Vet World Vol.14 November-2021 Article-20

Review Article

Veterinary World, 14(11): 2984-2995

https://doi.org/10.14202/vetworld.2021.2984-2995

I. Hernández-Avalos¹, D. Mota-Rojas², J. E. Mendoza-Flores³, A. Casas-Alvarado², K. Flores-Padilla², A. E. Miranda-Cortes¹, F. Torres-Bernal², J. Gómez-Prado², and P. Mora-Medina⁴

1. Department of Biological Sciences, Clinical Pharmacology and Veterinary Anesthesia, Faculty of Higher Studies Cuautitlán FESC, Universidad Nacional Autónoma de México, State of Mexico 54714, Mexico.
2. Neurophysiology of Pain, Behavior and Assessment of Welfare in Domestic Animals, DPAA, Universidad Autónoma Metropolitana, Mexico City 04960, Mexico.
3. Equine Hospital Faculty of Higher Studies Cuautitlán FESC, Universidad Nacional Autónoma de México, State of Mexico 54714, Mexico.
4. Department of Livestock Sciences, Animal Welfare, FESC, Universidad Nacional Autónoma de México, State of Mexico 54714, Mexico.

Background and Aim: Pain and anxiety are two of the most important concerns in clinical veterinary medicine because they arise as consequences of multiple factors that can severely affect animal welfare. The aim of the present review was to provide a description and interpretation of the physiological and behavioral alterations associated with pain and anxiety in equines. To this end, we conducted an extensive review of diverse sources on the topic. The article begins by describing the neurophysiological pathway of pain, followed by a discussion of the importance of the limbic system in responses to pain and anxiety, since prolonged exposure to situations that cause stress and pain generates such physiological changes as tachycardia, tachypnea, hypertension, hyperthermia, and heart rate variability (HRV), often accompanied by altered emotional states, deficient rest, and even aggressiveness. In the long term, animals may show deficiencies in their ability to deal with changes in the environment due to alterations in the functioning of their immune, nervous, and endocrinologic systems. In conclusion, pain and anxiety directly impact the homeostasis of organisms, so it is necessary to conduct objective evaluations of both sensations using behavioral scales, like the horse grimace scale, complemented by assessments of blood biomarkers to analyze their correlation with physiological parameters: Heart rate, respiratory rate, HRV, the parasympathetic tone activity index, lactate and glucose levels, and temperature. Additional tools – infrared thermography, for example – can also be used in these efforts to improve the quality of life and welfare of horses.

Keywords: anxiety, equines, nociception, pain, welfare.

How to cite this article: Hernández-Avalos I, Mota-Rojas D, Mendoza-Flores JE, Casas-Alvarado A, Flores-Padilla K, Miranda-Cortes AE, Torres-Bernal F, Gómez-Prado J, Mora-Medina P (2021) Nociceptive pain and anxiety in equines: Physiological and behavioral alterations, Veterinary World, 14(11): 2984-2995.

Received: 24-05-2021 Accepted: 23-09-2021 Published online: 26-11-2021

Corresponding author: D. Mota-Rojas E-mail: dmota100@yahoo.com.mx

DOI: 10.14202/vetworld.2021.2984-2995

Copyright: Hernández-Avalos, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.