Regional Institute for Veterinary Emergencies & Referrals

2132 Amnicola Hwy Chattanooga, TN 37406

Phone : 423-698-4612

Fax : 423-622-8145

Our Management Team

Dr. Sallye Gregg - Medical Director

Our Veterinarians

Dr. Sallye Gregg, DVM, graduated in 1980 with a BS in Animal Science from the University of Tennessee Knoxville. She continued at The University of Tennessee College of Veterinary Medicine where she received her Doctor of Veterinary Medicine in 1983. Dr. Gregg spent the next seventeen years working and managing a full service private practice in Cleveland, Tn. In 2000 she moved with her family to Charleston, South Carolina where she served as the Medical Director for the Greater Charleston Emergency Clinic, and Mt. Pleasant Emergency Clinic. From 2002-2006 she completed a residency in Emergency and Critical Care while serving as the Director of the Emergency Department at North Carolina State University College of Veterinary Medicine. Dr. Gregg is currently serving as the Hospital Director of the Regional Institute for Veterinary Emergencies & Referrals (RIVER). Dr. Gregg lives in Ooltewah with her husband Steve, and has two sons Dustin and Will. When she's not at the hospital, you can find her riding her Harley-Davidson, reading, or doing cross-stitch.



Donna Oster - Hospital Manager

Our Management Team

Donna Oster is the Hospital Manager at RIVER. She has been at RIVER for 8 years and in the veterinary field for 26 years.



Tim Maddox - Hospital Nursing Supervisor

Our Management Team

Tim Maddox has been involved in Veterinary medicine for 22 years. He got his first start at Animal Medical Center in Cleveland TN as a volunteer in middle school. Tim has been avid in the sports of showing dogs and currently has german shepherds. He also shares his home with a golden retriever, Caroline, two German Shepherds, Kennedy and Liberty, a Sulfur Crested Cockatoo, Sophia and a kitty named Suzy Q. In Tim’s spare time he loves playing all sports and his a huge Tennessee Vols fan.



Dr. Cheryl Braswell - Veterinary Internship Coordinator

Cheryl Braswell

Dr. Braswell has been practicing veterinary medicine for 36 years, graduating from the University of Georgia in 1979. She originally started her career as an associate small animal general practitioner. After 5 years she established her own business and continued in general practice for the next 17 years. Having retired from general practice in 2005, she pursued a residency in small animal emergency and critical care. In addition to her diplomate status in the American College of Veterinary Emergency and Critical Care (2012), Dr. Braswell is also a Certified Veterinary Hyperbaric Technologist (2013) and is currently seeking certification in veterinary pain management.



Blake Tutton, LVMT - Surgery Department Head

Our Management Team

Blake is originally from Atlanta, Georgia and moved to the Chattanooga area when he was twelve. He started his career in veterinary medicine through the Emergency Department of R.I.V.E.R. as a veterinary assistant. He graduated from Chattanooga State Technical Community College in 2013 with a degree in Veterinary Technology. Blake has now been a Licensed Veterinary Medical Technician for 2 years and is currently working towards his Veterinary Technician Specialty in the field of Surgery. Through the Academy of Veterinary Surgery Technicians, he plans to sit for his specialty exam in 2017. Blake is currently the Department Head of Surgery at R.I.V.E.R. and has an interest in orthopedic surgery and wound healing. Outside of work, Blake loves spending time with his 3-year old Australian Shepherd, named Riggs, as well as any outdoor activity.



Patricia Senestrari - ER Head Technician

Our Management Team

Patricia is the head technician for the weekend day shift ER service. She is also the contact official for OSHA at R.I.V.E.R. Patricia was born in Bogota, Colombia from a Colombo-Argentinean family. She graduated in 2000 from Fundacion Universitaria San Martin as Doctor in Veterinary Medicine and Zootechnics as Top 3 in her class.

She did her internship in Exotic Fauna and Zoo Practice and Management in the Santacruz Zoo, two hours outside of Bogota. She moved to Chattanooga in 2001, while finishing her requirements for a license to practice veterinary medicine in the United States. Patricia is fluent in both English and Spanish. She has a Great Pyrenees, named Freya and some of her interests include international travel, veterinary emergency, and wild life.