Review of the Foundational Knowledge Required for Assessing Horse Welfare

Abstract

A detailed understanding of what is usual for a species under optimal conditions is critical for identifying and interpreting different features of body function that have known impacts on animal welfare and its assessment. When applying the Five Domains Model to assess animal welfare, the key starting point is therefore to acquire extensive species-specific knowledge relevant to each of the four physical/functional Domains of the Model. These Domains, 1 to 4, address areas where objective information is evaluated and collated. They are: (1) Nutrition; (2) Physical environment; (3) Health; and (4) Behavioural interactions. It is on the basis of this detailed knowledge that cautious inferences can then be made about welfare-relevant mental experiences animals may have, aligned with Domain 5, Mental State. However, this review is focused entirely on the first four Domains in order to provide a novel holistic framework to collate the multidisciplinary knowledge of horses required for undertaking comprehensive welfare assessments. Thus, inferring the potential mental experiences aligned with Domain 5, the final step in model-based welfare assessments, is not considered here. Finally, providing extensive information on free-roaming horses enables a better understanding of the impacts of human interventions on the welfare of horses in both free-roaming and domestic situations.

Rethinking the utility of the Five Domains model

“…The model proposes four physical/functional domains (nutrition, environment, health and behaviour (recently renamed ‘behavioural interaction’ [Mellor et al 2020 ]) and the fifth domain is the so-called mental state. The basic idea is that the welfare state reflects the sum of the animal’s mental experiences (Harvey et al 2022 ). Hence, the welfare status of an animal is a direct function of the feelings of the animal: the mental domain.…”

“…There have been a limited number of studies to apply the Five Domains model to the welfare of pet dogs ( Canis familiaris ) (Littlewood & Mellor 2016 ; Ledger & Mellor 2018 ). Several recent studies have applied the Five Domains model to the welfare of domestic horses ( Equus caballus ) (McGreevy et al 2018 ; Mellor & Burns 2020 ; Fletcher et al 2021 ; Harvey et al 2022 ).…”

Mental Experiences in Wild Animals: Scientifically Validating Measurable Welfare Indicators in Free-Roaming Horses

“…Based on previously published information, potential welfare status and welfarealerting indicators were listed, all of which had been demonstrated to be practically assessable in free-roaming wild horses [2,[8][9][10].…”

“…A Ten-Stage Protocol for applying the Five Domains Model for assessing welfare, using free-roaming wild horses as an example, has been published (summarised in Table 1) [2]. Stage 3 of the Protocol, which requires reviewing the current knowledge of free-roaming wild horses within each of the four physical/functional domains, has also been published [8]. This knowledge underpinned Stages 4 to 6 of the Protocol in which novel methods for practically measuring/observing a range of animal-based welfare indicators in free-roaming horses were developed, evaluated, and described [9].…”

Isolation and Characterization of Bacteriophage Streptococcus equi for Application against Horse Strangles

“…For this purpose, new alternative approaches in therapeutic measures are required, namely the use of specific phage therapy in relation to Streptococcus equi. Bacteriophages have the ability to penetrate bacterial cells, reproduce in them and cause their lysis (Möller and Wöckener 2020;Domingo-Calap and Delgado-Martínez 2018;Jaramillo-Morales et al 2023;Harvey et al 2022).…”