Duncan graduated from the University of Sydney in 2013. He worked initially in rural mixed practice for 18 months, before completing an internship in equine medicine and surgery at the Marion duPont Equine Medical Center in Virginia.
After his internship, he worked in a private equine practice in Brisbane. This was followed by an equine surgery residency between both the University of Melbourne and University of Queensland from 2019 to 2022. During this time, he performed research on bone biomechanics as part of the Equine Limb Injury Prevention Program.
Duncan became a Diplomate of the American College of Veterinary Surgeons (Large Animal) in 2023.