Veterinary School: University of Wisconsin–Madison 

Internship Training: University of Pennsylvania 

Residency Training: University of Pennsylvania 

Additional Specializations: Diplomate American College of Veterinary Internal Medicine (ACVIM) 

Dr. Siobhan O’Neill is a board-certified small animal internal medicine specialist at SAGE Veterinary Centers-Campbell. Originally from Wisconsin, she completed her undergraduate studies at Barnard College, Columbia University. Her passion for animal care was ignited during her time as an animal keeper at the Bronx Zoo, leading her to pursue veterinary medicine. 

After earning her Doctor of Veterinary Medicine degree from the University of Wisconsin–Madison, Dr. O’Neill undertook a one-year rotating internship followed by a three-year residency in internal medicine at the University of Pennsylvania. She achieved board certification in 2012. 

Dr. O’Neill has practiced in Manhattan and Los Angeles alongside her husband, Dr. Jason Arndt, a veterinary cardiologist. They relocated to Idaho to embrace a family-friendly environment and the great outdoors. Dr. O’Neill collaborates with a team of dedicated professionals, many of whom she has worked with in previous cities. 

Outside of her veterinary practice, Dr. O’Neill enjoys yoga, hiking, gardening, downhill skiing, and spending quality time with her family, which includes two children, three dogs, and a cat.