Dr. Gallagher is originally from the Philadelphia area. He completed an undergraduate degree at St. Joseph's University, then completed a master's degree in laboratory animal science at Drexel University. He attended St.

George's University for veterinary school and completed his clinical year at the University of Pennsylvania. After graduation he worked in veterinary emergency medicine before transitioning to primary care medicine.

In his spare time, Dr. Gallagher enjoys fishing, hiking, scuba diving, traveling, and spending time with his dog, Mako.