Meet the Veterinarians
Dr. Janine Callen - Owner and Veterinarian
Dr. Janine Callen has spent most of her life in the Butler area. She always had a love for helping animals - so much so that her family and friends always assumed that she would become a veterinarian. She earned her Doctor of Veterinary Medicine degree from Purdue University School of Veterinary Medicine in 1994, then worked in Vermont for two years before moving back to the area and working in the North Hills. Dr. Callen purchased Twinbrook Animal Clinic from Dr. Mike Nagel in 1997. Being an advocate for her patients as well as forming special relationships with her clients and patients are what she values most about her profession. Dr. Callen is a Certified Canine Rehabilitation Therapist and loves what physical therapy and nonpharmaceutical pain management can do for our pets.
Dr. Callen shares her home with her husband and two dogs: Jack, a Toy Manchester Terrier; and Sally, a Pit Bull/Cattle Dog mix. In her spare time, she enjoys walks with Sally and riding her Quarter horses, Nic and Harley.
Dr. Laurie Schessler - Associate Veterinarian
Dr. Laurie Schessler obtained her Doctor of Veterinary Medicine degree from Purdue University College of Veterinary Medicine in 1995. In 2003, she became part of Twinbrook Animal Clinic, Inc. and loves how compassionate their team is about what they do. Dr. Schessler’s primary motivation for being a veterinarian is to make a difference in the health and well-being of pets.
Dr. Schessler enjoys outdoor activities but nothing beats quality time with her husband and three children! She also appreciates some downtime spent reading. Her house is not a home without her Cocker Spaniel, Oreo, her cats, Ernie and Winnie, and her bunny, Oswald a.k.a Ozzy.
Dr. Leeann Oliver - Associate Veterinarian
Dr. Leeann Oliver is a graduate of Tufts University School of Veterinary Medicine and earned her degree in 1996. In 1999, she started working at Twinbrook Animal Clinic, Inc. While she enjoys all aspects of the practice, Dr. Oliver has come to especially appreciate working with geriatric patients and those with chronic conditions, with a special interest in pain management and palliative care. She is a 'Cat Friendly Certified Veterinarian' and a member of the Senior and Geriatric Dog Society.
Dr. Oliver enjoys music, traveling, and most of all, time at the lake with her family in Canada.
Dr. Shawna Rau - Associate Veterinarian
Dr. Shawna Rau graduated with a Bachelor of Science degree from Cornell University in 1994 and received her Doctor of Veterinary Medicine degree from Ohio State University in 1998. She joined Twinbrook Animal Clinic, Inc. in June of 2008 and loves being part of a respectful, dedicated, and compassionate team. Dr. Rau grew up in a home with animals and has always known that Veterinary Medicine would be her career. It’s important for Dr. Rau to present Science-based information and educate pet owners to make informed decisions regarding quality preventative care and treatment. She enjoys narrating stories in the exam room about her dogs, cats, reptiles and fish, as well as how caring for them has helped her connect with her patients and owners.
Dr. Rau shares her home with her family as well as: a Pit Bull, Moggie; 4 cats, Lucie, Pansie, Mongo, and Leta; a Red Tail Boa, Djumu; a Bearded Dragon, Voldemort; a Leopard Gecko, Bao; and a variety of fish in tanks and a Koi pond. She enjoys staying busy with her family’s activities and sports events as a participant and a spectator. In her free time, she can also be found outdoors either running, scuba diving, traveling, eating interesting food, and taking advantage of the arts and entertainment of Pittsburgh.
Dr. John Tuttle - Associate Veterinarian
Dr. John Tuttle earned a Bachelor of Science from the University of Pittsburgh in 2008 and a Doctor of Veterinary Medicine from the University of Pennsylvania School of Veterinary Medicine in 2012. Since his arrival at Twinbrook Animal Clinic, Inc. in 2022, Dr. Tuttle has been grateful for the opportunity to work with a group of compassionate and skilled individuals who are dedicated to providing top-notch veterinary care to the community. Dr. John Tuttle is driven by the positive impact he makes on the lives of patients and their families.
Dr. Tuttle enjoys playing and watching soccer in his spare time, and he frequently volunteers as a youth sports coach. He also enjoys playing guitar and spending time being active with his family.