Inside the Interaction: Contact With Familiar Humans Modulates Heart Rate Variability in Horses

Affective Implications of Human-Animal Relationship on Pig Welfare: Integrating Non-Linear Heart Rate Variability Measures

The human-animal relationship is crucial for animal welfare. Gentle handling enhances pigs' comfort while rough handling causes fear and stress. This study examined how different human-animal relationship qualities affect the behavior and heart rate variability (linear and non-linear parameters) of 36 nursery pigs. Over six weeks, pigs experienced positive (n = 12), minimal (n = 12), or negative (n = 12) human handling. Their responses to handlers were then assessed in an experimental arena with four phases: habituation, exposure to the handler standing and sitting, and forced interaction. Pigs subjected to negative handling exhibited increased fear-related behaviors, spending less time in contact with the handler. They also exhibited heightened stress responses, with greater LF/HF ratio and Lmean values compared with positively handled pigs. Conversely, gently handled pigs displayed affiliative behaviors, accepting more strokes, and higher parasympathetic activation, indicated by greater RMSSD/SDNN and SampEn values, suggesting a more positive affective state. Minimally handled pigs exhibited some behavioral similarities to gently handled pigs, although physiological data indicated that the interaction was likely more rewarding for the gently handled pigs. These results emphasize the impact of human-animal relationships on pig welfare and highlight the value of incorporating non-linear heart rate variability parameters in such evaluations.

Donkey Heart Rate and Heart Rate Variability: A Scoping Review

Heart rate (HR) and heart rate variability (HRV) are commonly used physiological measures in animals. While several studies exist on horse HRV, less information is available for donkeys. This scoping review aims to understand the extent and type of published evidence on donkey HR and HRV, their clinical and research applications, the devices used, and the analysis performed. Only quantitative primary studies published in English were considered. Four different databases were queried through the Web of Science platform, with additional evidence identified by citation chasing. After a two-stage screening phase, data were extracted considering study and population characteristics, information on HR/HRV analysis, and applications. The majority of the 87 included articles (about 80%) concerned a sample size of up to 20 individuals and were published since 2011 (about 65%). Forty-one articles employed an electronic device for signal acquisition (mainly electrocardiographs and heart rate monitors), yet only two articles reported HRV parameters. The literature on donkey HRV is lacking, and this gap can be filled by gaining knowledge on donkey characteristics and finding useful tools for welfare assessment. Comparison with what is known about the horse allows a discussion of the technical and interpretative difficulties that can be encountered with donkeys.

The Impact of Noise Anxiety on Behavior and Welfare of Horses from UK and US Owner’s Perspective

Noise anxiety is an over-reaction to loud noises commonly detected among pets and can greatly impact on their welfare and on their management. When exposed to noisy events, horses can show intense escape attempts, which may cause severe accidents for the horse and the rider/handler. The aim of the present study was to investigate, through a web survey, UK and US owners’ perception of noise anxiety severity in their horses, their management strategies and perceived efficacy. The questionnaire was shared via social networking and advertised as “What is your horse afraid of?”. Over a total of 1836 questionnaires filled out; 409 owners reported that their horse has shown unusual behavior during a noise event. A two-step cluster analysis identified two groups: very anxious (VA) and slightly anxious (SA). VA horses were reported to have higher frequency of anxiety behaviors; higher frequency of signs of noise reactivity; and their anxiety did not improve with time. The most used management strategies consisted in providing hay throughout the night, turning in/out their horse or moving it to a paddock. A binomial logistic regression identified that horses that have reported injuries during noise events were more likely to be clustered as VA (OR = 0.24, 95% CI: 0.08–0.76); while providing hay throughout the night was more likely to be very effective management strategy in SA horses (OR = 0.41, 95% CI: 0.16–1.01). Our results confirmed that noise anxiety is a growing behavioral problem that can lead to important welfare concerns for horses. New management strategies, including the use of medicinal products, should be considered to reduce behavioral and physiological signs and help horses to cope with noisy events.

Nociceptive pain and anxiety in equines: Physiological and behavioral alterations

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, theparasympathetic 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.

The Effect of Human-Horse Interactions on Equine Behaviour, Physiology, and Welfare: A Scoping Review

Simple Summary

Human–horse interactions (HHIs) are an important aspect of society, especially in the equine industry. HHIs are diverse and can be focused on horses as an economic means, pleasure, or companionship for humans. As a result, the welfare of horses during these interactions, including their mental and physical health, is an important consideration. Although the physical health of horses can be readily measured during equestrian activities, their mental health is more difficult to assess. This review was conducted to evaluate what is known about the horse’s mental state during common HHI in an attempt to better understand the welfare of the horse.

Abstract

Human–horse interactions (HHIs) are diverse and prominent in the equine industry. Stakeholders have an invested interest in making sure that HHIs are humane. Assessment of equine welfare goes beyond physical health and includes assessment of the emotional state of the animal. HHIs can have a permanent effect on human–horse relationships, thereby influencing welfare. Therefore, an understanding of the horse’s affective state during HHIs is necessary. A scoping review was conducted to: (1) map current practices related to the measurement of HHIs; (2) explore the known effects of HHIs on horse behaviour and physiology; and (3) clarify the connection between HHIs and equine welfare. A total of 45 articles were included in this review. Studies that used both physiological and behavioural measures of equine response to human interactions accounted for 42% of the included studies. A further 31% exclusively used physiological measures and 27% used behavioural observation. Current evidence of equine welfare during HHIs is minimal and largely based on the absence of a negative affective state during imposed interactions. Broadening the scope of methods to evaluate a positive affective state and standardization of methodology to assess these states would improve the overall understanding of the horse’s welfare during HHIs.

Physiological and Behavioral Benefits for People and Horses during Guided Interactions at an Assisted Living Residence

Assisted living is a fast-growing living option for seniors who require residence-based activities for maintaining mental and physical health. Guided equine interactions may benefit seniors, so an on-site equine program was started at Hacienda at the River senior living community. For research purposes, twenty-four residents and associates, aged fifty-five or over, consented to physiological measurements before, during and after four guided sessions of stroking one of three horses for 10 min over 4–6 weeks. Heart rate variability (HRV) was measured simultaneously in humans and horses during interactions. We hypothesized that human heart rate (HR) and HRV would increase during stroking and HRV power would shift toward the very low frequency (VLF) range common in horses, indicative of healthy function. During stroking, human HR increased (p < 0.05) but HRV (SDRR) and %VLF of HRV power did not change. Diastolic blood pressure (DBP), an exploratory measure, significantly increased after stroking, consistent with arousal. Two horses showed no significant changes in HR or HRV, but one relaxed. Sixteen horse–human pairs demonstrated synchronized HRV peak frequencies during sessions, suggestive of social connection. Participants used more positive than negative words describing their experience during exit interviews (p < 0.05). These data show that horses animate seniors without causing emotional stress and provide opportunities for social bonding.