Abstract: The conflicting results regarding the study of motor laterality in horses may indicate that there does not exist a proper method to assess the degree and the direction of motor bias in these animals. Unfortunately, even less is known about the development of laterality in horses, and to what extent early manipulations can still exert their effects in adulthood. We propose a new method that can be easily applied at a very early age thus avoiding testing adult horses eventually biased by human handling and/or training. Forty-six horses (29 nine-month-old foals and 17 two-year old horses) were handled since birth bilaterally and housed in groups in wide areas. At the time of the analysis, in order to minimize environmental and sensorial disturbances, each horse was tested in a round pen individually or as dyad mother-foal. The ability/inability to properly execute a circle at trot was then recorded, assuming the direction of derailment, i.e. the cutting of the circle, as an indicator of motor bias. From the results of the study it is arguable that motor laterality in horses is acquired over time: in fact foals tested while their mothers were being subjected to longeing showed a higher percentage of ambidextrous animals, while two-year-old horses appeared biased toward the right (p<0.05). Results are discussed in the light of the scientific knowledge about equine biomechanics, taking into account horses' locomotion that leads to the advancement of the body mass through the activation of a kinetic chain that originates from the hindquarters.

Abstract: Debate persists over whether animals develop innovative solutions primarily in response to needs or conversely whether they innovate more when basic needs are covered and opportunity to develop novel behaviour is offered. We sourced 746 cases of “unusual” behaviour in equids by contacting equid owners and caretakers directly and via a website (https://innovative-behaviour.org), and by searching the internet platforms YouTube and Facebook for videos. The study investigated whether differences in need or opportunity for innovation were reflected in the numbers of different types of innovations and in the frequencies of repeating a once-innovative behaviour (i) with respect to the equids' sex, age, and breed type, (ii) across behavioural categories, and whether (iii) they were affected by the equids' management (single vs group housing, access to roughage feed, access to pasture, and social contact). We found that the numbers of different types of innovation and the frequency of displaying specific innovations were not affected by individual characteristics (sex, age, breed or equid species). Few types of innovation in escape and foraging contexts were observed, whilst the comfort, play, and social contexts elicited the greatest variety of innovations. We also found higher numbers of different types of innovations in horses kept in groups rather than in individual housing, and with unlimited rather than with restricted access to pasture and roughage. Equids in permanent social contact performed high rates of once-innovative behaviour. We suggest that equids produce goal-directed innovations and repeat the behaviour at high frequency in response to urgent needs for food and free movement or when kept in conditions with social conflict. However, equids devise the greatest variety of innovations when opportunity to play and to develop comfort behaviour arises and when kept in good conditions.

Abstract: This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia – mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0.8<K<1). The key specific and sensitive behavioural indices were response to palpation of the painful area, posture, and, of lesser value, pawing on the floor, kicking at abdomen and head movement. Of particular interest was the statistical correlation observed between the CPS and both non-invasive blood pressure (P<0.0001) and blood cortisol (P<0.002). This study established the value of some behavioural and physiological criteria in determining equine orthopaedic pain intensity and clearly demonstrated that pre-emptive, multimodal analgesia provided better management than the two other protocols tested.

Abstract: ABSTRACT For many ecosystems, feral horses are increasingly becoming an important if not dominant component of ungulate biomass and hence influence on community dynamics. Yet we still know little of how horses contribute to key ecological interactions including predator-prey and indirect competitive relationships at a community level. Notably, feral species like horses can exhibit life-history traits that differ from that of native (mainly artiodactyl) herbivore competitors. Artificial selection for traits like increased, early, or extended reproduction that have yet to be reversed by natural selection, coupled with naturally selected differences in anatomy and behavior, in addition to unique management objectives for horses compared to other species, means that the dynamics of feral horse populations are not likely to align with what might be expected of other large herbivores. Unexpected population dynamics and inherent biological asymmetries between native ungulates and feral horses may therefore influence the former via direct competition for shared resources and through enemy-mediated interactions like apparent competition. In several localities feral horses now co-exist with multiple native prey species, some of which are in decline or are species at risk. Compounding risks to native species from direct or indirect competitive exclusion by horses is the unique nature and socio-political context of feral horse management, which tends towards allowing horse populations to be limited largely by natural, density-dependent factors. We summarize the inherent asymmetries between feral horse biology and that of other ungulate prey species with consequences for conservation, focusing on predator-prey and emerging indirect interactions in multi-prey systems, and highlight future directions to address key knowledge gaps in our understanding of how feral horses may now be contributing to the (re)structuring of food webs. Observations of patterns of rapid growth and decline, and associated skews in sex ratios of feral horse populations, indicate a heightened potential for indirect interactions among large ungulate prey species, where there is a prevalence of feral horses as preferred prey, particularly where native prey are declining. In places like western North America, we expect predator-prey interactions involving feral horses to become an increasingly important factor in the conservation of wildlife. This applies not only to economically or culturally important game species but also at-risk species, both predators (e.g., wolves [Canis lupus], grizzly bears [Ursus arctos]) and prey (e.g., woodland caribou [Rangifer tarandus caribou]), necessitating an ecological understanding of the role of horses in natural environments that goes beyond that of population control. ? 2021 The Wildlife Society.