Mary Duncan graduated from the University of Illinois College of Veterinary Medicine in 1981. After working at St. Joseph Animal Hospital part time for a year, she was hired as Dr. Birk's first Associate Veterinarian in 1986 and has been a mainstay of the practice ever since. She is the primary surgeon at St. Joseph Animal Hospital and estimates she has spayed over 20,000 dogs during her tenure in east central Illinois. When away from veterinary medicine, Mary loves to travel. She has most recently enjoyed time in Ireland, Alaska, and on a sailing trip near St. Thomas.