Meet the Staff

Dr. Shay Redfield grew up in northern Australia and graduated high school there before moving to the United States. She received undergraduate and graduate training at University of California, Davis. While in veterinary school she focused on small animal medicine. She has since worked in emergency and critical care as well as general day practice. Prior to and during veterinary school she worked as a veterinary technician.

Dr. Redfield has a life long love of animals and grew up wanting to be a veterinarian from a young age in Australia. Today she enjoys her life in Chicago with her husband, two sons, two dog’s, two cat’s and various other animals. When not being a vet she spends time gardening, reading, biking and hiking.

Special Interests: Dr. Redfield’s chief areas of interest are internal medicine, ultrasound, and critical care. She loves being a vet and the challenges of all aspects of medicine.

Dr. Pass graduated from Michigan State University, College of Veterinary Medicine in 1975. His veterinary career began at Boone Animal Hospital, where he worked from 1976-1981. After a brief hiatus, during which he received his certification from the American Board of Veterinary Practitioners in 1984, he returned to Boone in 1987 and has been here ever since.

Dr. Pass enjoys working with all breeds of dogs and cats. His all time favorites were a yellow lab, named Jack, and a black short hair cat, Buddy. When Dr. Pass is away from the office, he likes to read, fish, and play golf.

Dr. Yvonne Costa is a 1987 graduate of The Ohio State University College of Veterinary Medicine. As an exclusive small animal doctor, she has been practicing at Boone Animal Hospital since 2002. Dr. Costa is a delight to all of her patients and their owners, as well as the entire staff at Boone Animal Hospital.

Dr. Costa enjoys the outdoors by biking, skiing, and walking her adopted dog, Ginger, affectionately nicknamed Gingivitis. Her indoor activities find her playing the guitar and sitting down with a good book. She loves to exercise!

In addition to Ginger, Dr. Costa’s family includes her husband and two children.

Dr. Clare Walker grew up in the Chicago area and wanted to be an animal doctor since she was eight years old. She attended Veterinary School at the University of Illinois and completed her training in 1991.

After 10 years in California, Dr. Walker returned to Illinois to enjoy the four season climate and be near her extended family. Dr. Walker has three children and a rescue cat named Eileen. Dr. Walker loves to write and recently completed a master’s degree in communications. She has written several informative handouts for the owners of our beloved Boone Animal Hospital patients.

Dr. Walker has also received recognition as Pet Partners’ Team Member of the Month.

Dr. Andrea Hayes received her Veterinary Medical Degree at the University of Pennsylvania. She completed a joint surgical residency at the Cummings School of Veterinary Medicine at Tufts and Angell Animal Medical Center in Massachusetts.

Dr. Hayes achieved her dream of helping dogs and cats by becoming a Board Certificated Surgeon in 1997.

When not attending to her many patients at Boone Animal Hospital, Dr. Hayes spends quality time with her son and husband, and she enjoys many extracurricular activities such as sports and music. Dr. Hayes is an avid gardener and loves being outdoors. She also enjoys spending time with her large pet family, including two dogs named Duke and Abigail; a cat named Jumpy; five rats named Katie, Peanut, Samantha, Jamie and Lucy; two guinea pigs, Perry and Nibbles; Emma, a gerbil; Ury the Uromastyx lizard; and many fish.