Dr. Allen was an honor graduate of the University of Missouri College of Veterinary Medicine, and was selected for a combined medical and surgical internship at Texas A&M. He also completed a three year residency training program in small animal surgery at the University of Minnesota.

The recipient of multiple teaching awards, Dr. Allen has presented his research nationally. In addition to his residency, Dr. Allen spent time in a private practice before returning to St. Louis, where he has provided advanced small animal surgery in multi-specialty referral practices. With over 20 years of experience practicing orthopedics, oncologic, general, thoracoabdominal and neurosurgery, Dr. Allen is also highly skilled in radiology, anesthesiology/pain management, and clinical pathology.