Meet our Veterinarians
Every veterinarian at Twinbrook Animal Clinic brings unique experience, interests, and perspectives to our practice. What we all share is a commitment to compassionate care, open communication, and helping pets live healthier, happier lives. We believe the best veterinary medicine is built on trust, teamwork, and lasting relationships with the families we serve.
Dr. Janine Callen
Veterinarian
From an early age, Dr. Janine Callen knew she wanted to dedicate her life to caring for animals. Her love for them was so evident that family and friends always assumed she would become a veterinarian. That lifelong passion led her to earn her Doctor of Veterinary Medicine degree from the Purdue University College of Veterinary Medicine in 1994.
After graduation, Dr. Callen practiced in Vermont for two years before returning to western Pennsylvania. In 1997, she purchased Twinbrook Animal Clinic and has been proud to continue its tradition of providing compassionate, personalized veterinary care to generations of pets and their families.
One of the most rewarding parts of veterinary medicine for Dr. Callen is building lasting relationships with her clients while serving as an advocate for her patients. She believes the best care comes from listening, educating, and working together with pet owners to develop individualized healthcare plans. By emphasizing preventive care, early intervention, and thoughtful treatment options, she strives to help every pet enjoy the healthiest, happiest life possible.
Dr. Callen is also a Certified Canine Rehabilitation Therapist and has a special interest in physical rehabilitation and non-pharmaceutical pain management. She enjoys helping pets improve their mobility, recover from injury or surgery, and maintain an active, comfortable quality of life.
At home, Dr. Callen and her husband share their lives with Sally, a Pit Bull/Cattle Dog mix. When she's away from the clinic, she enjoys taking walks with Sally and spending time with her Quarter Horses, Nic and Harley.
Dr. Laurie Schessler
Veterinarian
Dr. Laurie Schessler earned her Doctor of Veterinary Medicine degree from the Purdue University College of Veterinary Medicine in 1995. She joined the Twinbrook Animal Clinic team in 2003 and has enjoyed being part of a practice that shares her commitment to compassionate, high-quality veterinary care.
For Dr. Schessler, the most rewarding part of veterinary medicine is making a positive difference in the health and well-being of her patients. She enjoys building relationships with pets and their families while helping them make informed decisions that support a lifetime of good health.
Outside the clinic, Dr. Schessler enjoys spending time outdoors, but nothing compares to being with her husband and their three children. She also enjoys relaxing with a good book. Her home is shared with Oreo, a Cocker Spaniel; Ernie and Winnie, her cats; and Oswald—better known as "Ozzy"—her rabbit.
Dr. Leeann Oliver
Veterinarian
Dr. Leeann Oliver earned her Doctor of Veterinary Medicine degree from the Tufts University School of Veterinary Medicine in 1996. She joined the Twinbrook Animal Clinic team in 1999 and has enjoyed caring for generations of pets and their families ever since.
While Dr. Oliver enjoys all aspects of small animal medicine, she has a special interest in caring for senior pets and those living with chronic medical conditions. She is especially passionate about pain management, palliative care, and helping older pets maintain the best possible quality of life. Dr. Oliver is a Cat Friendly Certified Veterinarian and a proud member of the Senior and Geriatric Dog Society.
Outside the clinic, Dr. Oliver enjoys music, traveling, and, most of all, spending time with her family at the lake in Canada.
Dr. Shawna Rau
Veterinarian
Dr. Shawna Rau earned her Bachelor of Science degree from Cornell University in 1994 before receiving her Doctor of Veterinary Medicine degree from The Ohio State University College of Veterinary Medicine in 1998. She joined the Twinbrook Animal Clinic team in 2008 and values being part of a respectful, dedicated, and compassionate group of professionals who share a commitment to exceptional patient care.
Growing up surrounded by animals, Dr. Rau always knew veterinary medicine was the career she wanted to pursue. She is passionate about providing science-based medical care and believes that educating pet owners empowers them to make informed decisions about preventive healthcare and treatment options. She especially enjoys getting to know her clients and often shares stories about her own pets, finding that those experiences help her connect with both pets and the people who love them.
Outside the clinic, Dr. Rau enjoys an active life with her family and a wonderfully diverse collection of pets. Her household includes Moggie, a Pit Bull; four cats-Lucie, Pansie, Mongo, and Leta; Djumu, a Red Tail Boa; Voldemort, a Bearded Dragon; Bao, a Leopard Gecko; and a variety of fish in both aquariums and a koi pond.
When she's not at Twinbrook, Dr. Rau enjoys spending time with her family, attending sporting events, running, scuba diving, traveling, discovering interesting foods, and taking advantage of the arts and entertainment that Pittsburgh has to offer.
Dr. John Tuttle
Veterinarian
Dr. John Tuttle earned his Bachelor of Science degree from the University of Pittsburgh in 2008 before receiving his Doctor of Veterinary Medicine degree from the University of Pennsylvania School of Veterinary Medicine in 2012. He joined the Twinbrook Animal Clinic team in 2022 and is grateful to be part of a compassionate, skilled group of professionals dedicated to providing exceptional veterinary care to the community.
For Dr. Tuttle, one of the most rewarding aspects of veterinary medicine is making a positive difference in the lives of his patients and the families who love them. He enjoys partnering with pet owners to provide thoughtful, personalized care that helps pets live healthier, happier lives.
Outside the clinic, Dr. Tuttle enjoys both playing and watching soccer and frequently volunteers as a youth sports coach. He also enjoys playing guitar and spending active time with his family.