Dr. Thomas Derstine received his Bachelor of Science degree in 1970 from Muhlenberg College and his Veterinary Degree in 1974 from the University of Pennsylvania. Rockhill was established in 1955. Dr. Derstine has been practicing veterinary medicine at Rockhill since 1974.

Dr. Derstine enjoys all aspects of pet care but has special interests in Dermatology, Ophthalmology and Surgery. When not practicing medicine, Dr. Derstine enjoys spending time with his wife and 2 daughters. He also enjoys discussing cases with his oldest daughter, Dr. Jennifer Derstine. His other interests include: fishing with Granddaughters (4), water sports and traveling. Dr. Derstine has one cat, Whitney.