Hemmelgarn received her bachelor of science degree from Utah State University and her doctor of veterinary medicine degree from Washington State University. Following veterinary school, Hemmelgarn went on to pursue a one-year small animal rotating internship at Garden State Veterinary Specialists and a three-year emergency critical care residency at Oradell Animal Hospital in Paramus, New Jersey. She has been practicing as a board-certified emergency and critical care specialist at BluePearl Specialty and Emergency Pet Hospital in its Brooklyn, New York, and Paramus, New Jersey, hospitals for the past 5 years.