Relationship between body condition and vertical movement symmetry in 109 riding school horses

Abstract

For riding schools, the health and function of their horses is paramount. Unfortunately, lameness and overweight are common problems in this population, and a causal relationship whereby increased body weight causes lameness is also possible. This observational field study investigated the relationship between body condition score (BCS) and motion movement asymmetries in riding school horses and also explored the relationships between BCS, movement asymmetry and subjectively scored willingness to work. Eight riding schools within 2.5 h by car from Uppsala, Sweden, were convenience-sampled and 3-24 horses from each were included in the study. Body condition was scored (scale 1-9) and vertical movement asymmetry data were collected in straight-line trot, using an inertial measurement unit system. Asymmetry parameters were calculated as the mean difference between local vertical displacement minima/maxima for the head/pelvis (HD/PD) between the two halves of the stride. A questionnaire was used to assess perceived willingness to work and energy level of the horses. The data were analysed with linear mixed models, t-tests and Mann-Whitney U-tests. A correlation was found between BCS and PDmin (), an asymmetry parameter related to hindlimb weight-bearing lameness, where PDmin increased by 0.96 mm for each unit increase in BCS. Horses with vertical movement classified as symmetric had lower BCS than horses with movement classified as asymmetric (5.4 ± 0.4 vs 5.7 ± 0.6, ). Horses classed as overweight (BCS ≥ 6) scored lower on willingness to work () and energy level (). These results indicate that the body condition of riding school horses may influence their function and the health of their locomotor apparatus. Further studies are required to identify the underlying mechanisms.