Subjective Evaluation of Muscle Conformation in Horses Subjected to Pace Training or not

Muscle conformation is often discussed among practitioners and it is sometimes suggested that specific training strategies affect muscle conformation. This study attempted to investigate; 1) if it is possible for practitioners to judge whether a horse is subjected to pace training or not based on subjective analysis of hind‐end muscle conformation and 2) which terminology practitioners would use when doing this. Methods Photos were taken from behind (transverse plane) in 10 Icelandic horses trained for mounted pace racing and 11 used for riding but not pacing. Body condition score was 7.4 and 7.5 ( SE 0.3, P>0.05) in pacers and non‐pacers, respectively (9 degree scale, ANOVA , Tukey test). Three experienced horse practitioners (A, B, C) were informed that the 21 photos showed horses trained for pace racing and horses not trained as pacers and they were instructed to separate photos into two groups based on their subjective impression of muscle conformation. Results Practitioner A divided horses into groups called “even” (n = 13) and “narrow” (n = 8); B into groups called “strong” (n = 11) and “weak” (n = 10); and C into “high” (n = 9) and “wedged” ” (n = 12). The practitioners assumed that “even”, “strong” and “high” horses were pacers and 10, 10 and 12 observations were correct in practitioner A, B and C, respectively (mean ±  SD : 51 ± 5%). The number of cases where all practitioners agreed and grouping also matched pacers and non‐pacers were 7. Conclusions It appears not to be possible to judge whether an Icelandic horse is pace trained based on observations of the hind‐end musculature. The terminology used appeared to refer either to the conformation or to a presumed strength. Ethical Animal Research Explicit owner informed consent for participation in this study is not stated. Sources of funding:  Holar University College, I celand. Competing interests:  none.