An investigation into horse owner/loaner knowledge on equine sleep and non-syncopal collapse.

Introduction: Sleep plays a vital role in the welfare of all animals. Horses sleep for between 3-4 hours and require 25-40 minutes of REM sleep in a 24-hour period, for which they must be recumbent (Greening and McBride,2022). Non-syncopal collapse has been associated with horses that cannot achieve a recumbent posture, such that REM sleep occurs whilst standing up (Haines, 2022). Due to muscle atonia associated with this sleep state, the horse then partially or fully collapses. The study’s aims were to determine overall understanding of equine sleep, and also to record owner experiences of equine non-syncopal collapse.
Materials and Methods: An online questionnaire was sent to equine Facebook groups such that the sample population of horse owners and loaners (N=75) was derived from volunteer and snowball sampling. Closed questions enabled statistical analysis (Mann Whitney U; P<0.05), where the participants were classified based on whether they believed horses typically slept for four hours or less (Group 1), or horses typically sleep for five hours or more (Group 2). Open questions captured owners’ experiences of collapse, which were subject to thematic analysis.
Results: Quantitative data revealed a gap in knowledge for most participants when asked how much sleep they thought their horse required. Overall, 41% of respondents believed that horses slept less than 4hrs and 59% believed horses slept more than 5hrs. A significant difference (Z=2.072, P= 0.038) was determined between group 1 (mean+SD= 1.4+0.76) and 2 (mean+SD=1.8+0.9) for whether participants were more likely to consider lack of sleep as a reason for lack of energy. Thematic analysis split management of collapse into three themes; environmental changes, medical treatment, and short-term changes. These themes were similar for the question asking about what veterinary advice was given, if it was given. Of the participants, 20% had experience with collapse. The majority described their horse as falling forwards onto their fetlocks or knees at the time of collapse, and all the horses were relatively calm at the time of collapse; they were almost all either grazing or standing quietly. The age of the horse did not seem to influence the description of the collapse episode.
Discussion and Conclusions: Ongoing education around equine sleep is important so that it is taken into consideration relative to aspects of performance and welfare. This study highlights the prevalence of collapse and how similar episodes are, suggesting similar underlying causes, however further research is required to link this to sleep problems and how to address these to reduce the occurrence of collapse.