After completing a research degree in animal production, Trepheena made the change to animal health and became a veterinarian. She worked in general practice for 8 years before moving into behaviour practice in 2012. Trepheena undertook specialist training and is a Diplomate of the American College of Veterinary Behaviorists. Trepheena has worked in both private behaviour practice and shelter behaviour. From 2015-2018, she managed the behaviour department in a large open-intake shelter, as the Animal Behaviour Manager and then acting General Manager of Animal Welfare. Trepheena now works mainly in private behaviour practice through her practice, Wild Things Veterinary Behaviour Services. She continues to consult for shelters, rescue groups and other animal organisations, lectures at conferences around Australia, and teaches veterinary students.