Find a Doctor Siobhan O’Neill

Siobhan O’Neill, DVM, DACVIM

Board-Certified Small Animal Internal Medicine Specialist

Siobhan O’Neill, DVM, DACVIM, is a Board-Certified Small Animal Internal Medicine Specialist who joined WestVet in May 2017.

She grew up in Wisconsin and attended Barnard College, Columbia University for her undergraduate education. Following her undergrad, Dr. O’Neill worked as an animal keeper at the Bronx Zoo and enjoyed working with animals so much that she decided on a career in veterinary medicine.

She obtained her veterinary degree from the University of Wisconsin-Madison, and then completed a one-year rotating internship at the University of Pennsylvania, followed by a three-year residency in internal medicine at the University of Pennsylvania. She earned board certification in 2012.

Following residency, Dr. Siobhan O’Neill practiced in Manhattan and Los Angeles, along with her husband, Dr. Jason Arndt (Cardiology) whom she met during their residencies in Philadelphia. Together they have two children, three dogs, and a cat.

Dr. O’Neill and Dr. Arndt moved to Idaho after the birth of their son to enjoy a more family-friendly environment and fresh air. She enjoys working with the great group of doctors at WestVet, many of whom she trained with and worked with in Madison, Philadelphia, and Los Angeles.

In her free time, Dr. O’Neill enjoys yoga, hiking, gardening, downhill skiing, and spending time with her family.

Bachelor of Science: Barnard College and Columbia University

Doctor of Veterinary Medicine: University of Wisconsin-Madison

Rotating Internship: University of Pennsylvania

Residency: University of Pennsylvania

Diplomate American College of Veterinary Internal Medicine (ACVIM)