He became an ACVS diplomate in 1972, a charter AVDC Diplomate in 1988 and a charter EVDC Diplomate in 1998. He spent his entire academic career at Penn as Professor of Surgery and Dentistry, until retiring in 2013. He is now Emeritus Professor.
His area of professional interest narrowed from General Surgery to Head, Neck and Chest Surgery, and then for most of his career at Penn, to Dentistry and Oral-Maxillofacial Surgery. His primary research interest for much of his academic career has been periodontal disease and prevention in dogs and cats.
He was instrumental in forming the Veterinary Oral Health Council, of which he has been Director since 1997.
He was President, and later Secretary-Executive Secretary, of AVDC for 14 years.
He is author of about 150 articles in peer-reviewed journals and many other articles and meeting abstracts, and was the recipient of many research grants. He has been a reviewer for many veterinary journals, and was Editor of Veterinary Surgery (the ACVS journal) from 1982-87, and Editor of the Journal of Veterinary Dentistry (the AVDC and EVDC journal) from 1994-2000.
He has received numerous awards, including the BSAVA Bourgelat Award, the Norden Distinguished Teaching Award, the Peter Emily AVDC Award, the American Veterinary Dental Society Education and Research Award, and the American Dental Hygienists Association Golden Scaler Award.