Angus O. McKinnon, BVSc, MSc, Diplomate, ACT and ABVP, Goulburn Valley Equine Hospital, Shepparton, Victoria, Senior Research Fellow, Center for Early Human Development, Monash University, Clayton, Victoria, Australia. James L. Voss, DVM, MS, Dean, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.