Since MM horses in this study were in the early stages of insulin dysregulation [23], it is believed that the shortening of SEL extent is possibly associated with the process of sinking DP [16], which may precede the characteristic stretching seen in horses artificially exposed to much higher blood insulin concentrations [21, 25] and in horses in more advanced stages of hyperinsulinaemia, which already have clinical evidence of laminitis [22]. This evidence concerns the gene INS and Miyoshi myopathy.