Emergency Service

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Dr. Jeff Nunez (Chief of Emergency Services) graduated from Louisiana State University in 1996. He completed a one year internship at Angel Memorial in Boston which has an annual case load of45,000 patients. He worked for a year in general practice before becoming anemergency clinician for a 24 hour referral hospital in 1998. He lives in Orange County with his daughter and two sons.


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Dr. Noelle White  attended the University of Tennessee where she received her  Bachelors and Doctorate of Veterinary Medicine.  Upon graduation, she practiced in an emergency hospital in Virginia for 3 years before joining TVRH in 2003.  Dr. White currently resides with her family in Garner, NC.   She lives with her husband, two children, a Pembroke Welsh corgi 'Manning', a green cheek conure 'Shirley', and numerous parrotlets and finches.



Dr. German Duran graduated from veterinary school in Colombia, South America where heinitially practiced. He moved to the US in 1998 and worked as a veterinary nurse with a referral practice for 5 years. In 2003 he was certified by theUS Veterinary Board and has practiced emergency medicine since that time.




Dr. Kate Hamon graduated from the University Of Tennessee College Of Veterinary Medicine in 2012. She then moved to Northern California and completed a one year rotating internship in small animal internal medicine, surgery, and emergency medicine at the VCA Sacramento Veterinary Referral Center. She stayed on in the area for another year, doing a mix of general practice and emergency. She has spent most of her life in the Triangle, and so decided to return, joining the emergency team at TVRH in 2014. She currently resides in Durham with her Plott hound mix, ‘Sadie’.


Dr. Bethany Walters is a Chapel Hill native and has lived in the Triangle for most of her life. Her undergraduate degree is in mechanical engineering, but she made the transition to veterinary medicine and could not be happier to be playing with animals every day. She graduated from NCSU College of Veterinary Medicine in 2014 and did two internships, one in small animal medicine and one in exotic animal medicine (she is happy to see whatever species walks/slithers/flies/swims through the door). Dr. Walters joined TVRH in 2016.


Dr. Katie Hoff is originally from Massachusetts, and graduated from Tufts Cummings School of Veterinary Medicine in 2015. Upon graduation, she practiced emergency medicine for three years in Philadelphia prior to joining TVRH. An alumna of Duke, she is happy to find herself back in Durham. She currently resides in Durham with her husband and their two pets- a cockatiel named Houdini and a mixed breed named Cameron. 

Critical Care Service


Dr. Mike Nystrom is a true local growing up in Cary and Apex. He graduated from the University of Tennessee College of Veterinary Medicine in 2013. Following graduation, he then went on to complete a one year internship at Tufts Cummings School of Veterinary Medicine in Massachusetts. After his internship he returned to the University of Tennessee to complete a specialty internship and then residency in emergency and critical care. He is very excited to return to the Triangle, with his wife and three kids.

Surgery Service

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Dr. Mike Grafinger graduated from Mississippi State University in 1999. He  completed a one year internship at Animal Medical Center in New York  City which has an annual case load of 50,000 patients and over 90  veterinarians. He practiced general medicine in NYC for one year before joining a North Carolina emergency and referral practice as an emergency  clinician. He completed a surgical residency at NC State Veterinary  School and is one of the few board certified surgeons affiliated with an  emergency clinic in the Durham area. He lives in Raleigh with his wife and three sons.



Dr. Cindy Eward was born and raised in Ottawa, Canada and graduated from the Ontario Veterinary College in 1996.  Following graduation, she completed an internship in small animal medicine and surgery at the college and a 3 year residency in small animal surgery at the Auburn University College of Veterinary Medicine.  She then spent 3 years working in academia at both the Ontario Veterinary College and Auburn University before moving on to referral and specialty practice.  Dr. Eward's research interests include oncologic surgery and she in often involved in projects with her husband, Will Eward, an orthopedic oncologist and veterinarian at Duke University Medical Center.  Her clinical interests include minimally invasive surgery, oncologic surgery, stent placement as well as the welcome diversity of soft tissue, orthopedic and neurologic surgery.  Dr. Eward lives on a small farm in north Durham with her husband, 3 kids and menagerie of pets.


Dr. Marc Hirshenson grew up in Rockville, Maryland.  He received a BS in Animal Science from the University of Marylandand his DVM from Tufts University. After graduation, Dr. Hirshenson completed a one-year internship in small animal medicine, surgery, and emergency and critical care and a three-year residency in small animal surgery at Cornell University.  He then returned to Maryland where he worked as a staff surgeon at a large specialty referral practice. For the last two and a half years he has served as the Chief of Surgery for a specialty hospital on Long Island.

Although he enjoys all aspects of veterinary surgery, Dr. Hirshenson is particularly interested in surgical oncology, canine stifle disease and repair, elbow disease, and wound reconstruction.  He is proficient in minimally invasive surgical procedures including arthroscopy, cystoscopy, laparoscopy, rhinoscopy and thoracoscopy.

Away from the hospital, Dr. Hirshenson enjoys swimming, spending time outside, traveling or catching an Orioles or Terrapins game.

Internal Medicine Service


Dr. Melissa Chrzanowski graduated from the University of Illinois College of Veterinary Medicine in 2010.  Following graduation, she completed a one year small animal rotating internship at the Veterinary Specialty Center in Buffalo Grove, IL.  After her internship, she stayed on at the Veterinary Specialty Center and completed her internal medicine residency in 2014.  She is very excited to be a part of the TVRH team. 

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Dr. Zachary Kern is originally from outside Chicago (Skokie, IL). He completed his undergraduate degree in the biological basis of behavior at the University of Pennsylvania, where he later completed his veterinary degree as well. He completed a rotating internship at BluePearl Veterinary Partners in New York City; an internal medicine internship at the Veterinary Specialty and Emergency Services in Rochester, NY; and a residency in small animal internal medicine at NC State University. He became a diplomate of the American College of Veterinary Internal Medicine in small animal internal medicine in 2019. He was also awarded a teaching certificate during his residency and enjoys educating pet owners, veterinary students, and referring veterinarians. Dr. Kern enjoys all aspects of internal medicine, but has a special interest in endoscopy, immune-mediated diseases, and renal and urinary tract disease.

Dr. Kern lives in Durham with his wife and his dog, Ethyl (a spunky pit bull mix). In his free time he enjoys hiking, travel, cooking, and running.

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Dr. James (Jim) Hummel is originally from the Northern Virginia area. He moved to the Triangle to attend veterinary school at NC State University (NCSU). After graduation from NCSU, he completed a small-animal rotating internship at Veterinary Referral Associates in Gaithersburg, Maryland, and then returned to NCSU to finish a residency in internal medicine. Dr. Hummel says he chose Internal Medicine because he loves problem solving.

Away from the hospital, Dr. Hummel enjoys spending time with his three girls: Olivia, Katie, and Sophia as well as running with his yellow lab, Finley.

Radiology Service


Dr. Lisa Woolman graduated from the University of Tennessee College of  Veterinary Medicine in 2004.  She then completed one year of internship  at The University of Pennsylvania in Philadelphia.   Dr. Woolman moved  to the triangle to begin a 4 year residency in Veterinary Diagnostic  Imaging at North Carolina State University in 2005.  She obtained board  certification in her specialty in 2009.  Dr. Woolman provides on-site  in-patient and out-patient imaging services for Triangle Veterinary  Referral Hospital.  She has settled in Chapel Hill with her husband, son, daughter and their pets, 2 dogs and 4 cats.

Cardiology Service


Dr. Jennifer Myers graduated from the Western College of Veterinary Medicine in Saskatchewan, Canada, in 2008. She then completed a one year small animal rotating internship at Garden State Veterinary Specialists and a one year cardiology internship at Animal Surgical and Emergency Center.  In 2010 she began a combined cardiology residency and masters degree at Colorado State  University.  She lives in Raleigh and has a small mixed breed dog named Bruce.

Oncology Service

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Dr. Jennifer Arthur graduated from veterinary school at Ross University in 2004 and completed a general medicine and surgery internship at Kansas State University in 2005.  While completing her Radiation Oncology residency at North Carolina State University in 2006-7 she fell in love with the Triangle area and planned on someday returning.  She spent 6 years in private practice specialty hospitals in Atlanta and then Phoenix before opting to pursue a second residency in Medical Oncology.