Dr. McCallion has been working various positions around VCA West Suburban Veterinary Hospital since 2013 and returned as an Associate Veterinarian in June, 2019. He particularly enjoys the excellent patient care and teamwork seen at WSVH, as well as the high-quality medicine and surgery practiced.

Raised in Darien, Dr. McCallion attended Augustana College, graduating with a Bachelor of Arts degree in Biology. He went on to receive his Doctorate of Veterinary Medicine from the University of Illinois College of Veterinary Medicine. Dr. McCallion has special interests in minimally invasive surgery, ophthalmology, and emergency medicine. He also has an interest in sled dog medicine and provides medical care to dogs participating in the Iditarod Trail Sled Dog Race in Alaska. He is a member of the International Sled Dog Veterinary Medical Association, Chicago Veterinary Medical Association, and American Veterinary Medical Association.

In his free time, Dr. McCallion can be found outside, as he enjoys hiking, traveling, and playing sports. He especially enjoys the U.S. National Parks and hopes to visit them all someday. He and his wife currently share their home with their 6-year-old rescue dog, Nala.