Meet Our Doctors | Meet Our Staff

Dr. Richard J. Howard

DVM, MS (Surgery)

Dr. Howard graduated from Auburn University with his D.V.M. degree in 1977, and worked for two years in small animal practice before entering a small animal surgical residency program at Kansas State University.  After completing his residency and earning a Master’s degree, he continued on at the KSU Veterinary Medical Teaching Hospital as an assistant professor in small animal surgery.

In the summer of 1983, Dr. Howard moved to Oregon, living in Grant’s Pass briefly before coming to Portland to establish the Animal Surgical Practice of Portland in early 1984. Dr. Howard’s surgical interest, expertise include general soft tissue reconstruction, gastrointestinal, oncologic, thoracic and orthopedic surgery. Dr. Howard studied with the late Dr. Barclay Slocum and was the first licensed surgeon to perform the TPLO procedure (1994), and he continues to explore alternatives in elbow and hip dysplasia management.

Dr. Howard is a member of numerous professional organizations, including the American Animal Hospital Association, the American Veterinary Medical Association, the Oregon Veterinary Medical Association, the Portland Veterinary Medical Association, and the Association for Veterinary Research and Education.

Dr. Howard has three grown children, two boys and a girl, as well as a dog. His personal interests include running with friends and his dog, and biking.

Dr. Michael Flynn

DVM, DACVS (Surgery)

Dr. Flynn attended veterinary school at Louisiana State University from 1984-88, where he graduated 1st in his class. He then completed a one year internship in small animal medicine and surgery at Angell Memorial Animal Hospital in Boston, followed by a 3-year residency in small animal surgery at North Carolina State University. A surgical implant that he developed during his residency is currently in widespread use in the treatment of hip dislocations. Following completion of his residency in 1992, Dr. Flynn spent the next 4 years on faculty at the Mississippi State University College of Veterinary Medicine, initially as a clinical instructor the first year, and subsequently as an assistant professor.

He became board-certified by the American College of Veterinary Surgeons in 1995. Dr. Flynn left the university to enter private referral practice in Michigan in 1996, and later moved to Portland in 1999. Dr. Flynn’s surgical expertise encompasses a wide range of soft-tissue surgery, orthopedics and neurosurgery. He has particular interest and experience in the areas of oncologic and reconstructive surgery.

Dr. Flynn is a member of the American College of Veterinary Surgeons, the Veterinary Society of Surgical Oncology, the American Veterinary Medical Association, and the Portland Veterinary Medical Association. He has lectured frequently at local and national meetings. Dr. Flynn enjoys all forms of outdoor activity, and pursues his passion for fly-fishing every opportunity he gets.

Dr. Regina Tobin

DVM, DACVIM (Internal Medicine)

Dr. Tobin is a board certified specialist in small animal internal medicine.  After receiving her D.V.M. at Cornell University in 1994, she completed a one year internship in small animal medicine and surgery at Angel Memorial Animal Hospital in Boston, Massachusetts. Dr. Tobin worked as a small animal practitioner in Boston for one year. In 1998, she completed a two year residency program in small animal internal medicine at the University of California at Davis. Dr. Tobin became board certified in internal medicine in 1999. She worked as a small animal internist in private referral practices in Oregon for six years before becoming an internal medicine consultant for a national diagnostic laboratory. Dr. Tobin joined Cascade Veterinary Referral Center in 2006.

Dr. Tobin’s main areas of clinical interest include renal disease, autoimmune disorders, gastrointestinal disease, and endocrine disorders. Her clinical research projects have focused on endocrine diseases and have been published in veterinary journals. She is skilled in a variety of endoscopic procedures, including bronchoscopy, gastrointestinal endoscopy, rhinoscopy, and cystoscopy. Dr. Tobin also administers chemotherapy to patients with cancer.

Dr. Tobin is a member of the American College of Veterinary Internal Medicine, American Veterinary Medical Association, Oregon Veterinary Medical Association, and the Portland Veterinary Medical Association.  She gives continuing education lectures on a variety of topics to veterinarians, veterinary technicians, and other veterinary clinic support staff.

Dr. Tobin believes her role as an internist is to offer her clients all diagnostic and treatment options appropriate for their pet, support her clients through difficult decisions, and provide compassionate high quality veterinary care for her patients.

Dr. Helen B. Hamilton

DVM, MS, DACVIM (Internal Medicine)

​Dr. Hamilton graduated Magna Cum Laude from the University of Georgia in 1982. She completed a one-year internship at the University of Minnesota in 1983, followed by a three-year Internal Medicine Residency and Masters Program at Colorado State University, becoming Board Certified in Small Animal Internal Medicine in 1986.

Dr. Hamilton moved to Northern California to join Santa Cruz Veterinary Hospital in 1987, serving as internal medicine specialist and Intern Director from 1987-1998. During this time she helped form Monterey Peninsula Veterinary Emergency Clinic.

In 1998, along with other specialty practitioners, Dr. Hamilton formed her own Veterinary Internal Medicine Service. Within a year she also formed Ohlone Veterinary Emergency Clinic, serving as President 1999-2013.

In 2009 she began mentoring fourth-year veterinary students from Western University of Health Sciences. She currently is a Clinical Professor at the veterinary school.

Dr. Hamilton’s main areas of clinical interest include gastrointestinal diseases, endocrine disorders (especially diabetes mellitus), canine reproduction, and oncology. She is a member of the American College of Veterinary Internal Medicine, American Veterinary Medical Association, California Veterinary Medical Association, and many California Veterinary associations.

Her personal interests include gardening, hiking, and canine-related activities. She has been showing Greyhounds in conformation, obedience and tracking since 1983, and, more recently, rally and agility. She has won numerous Specialties and Specialty High In Trial awards. Hers was the second Greyhound to earn a MACH2 (Master Agility Championship), and she holds the record for TDX Greyhounds (8 to date). She was president of the Greyhound Club of Northern California for many years, and currently is an active member of the Greyhound Club of America.

Dr. Hamilton is currently involved in a research project with Western University involving Greyhound tick-borne diseases and hematologic abnormalities.

She moved to Portland in 2016 to join Cascade Veterinary Referral Center.