Our Team

Meet Our Doctors

Surgery

Andrew Grange

BSc (Hons), BVetMed, Diplomate ACVS

Dr. Andrew Grange is a Diplomate of the American College of Veterinary Surgeons, and Chief of Staff of OakVet Animal Specialty Hospital. He attended University College London where he received his bachelor’s degree in orthopedic science, and then graduated in 2008 from the Royal Veterinary College in London with a degree in veterinary medicine. Following graduation he completed a rotating internship in Southern California, and a residency in small animal surgery at Angell Animal Medical Center in Boston, MA. 

His professional interests include the application of minimally invasive surgical techniques (Arthroscopy, Laparoscopy, and Thoracoscopy) in the management of soft tissue and orthopedic disease, and the surgical treatment of cruciate disease, fractures, and Total Hip Replacement. 

Dr. Grange’s personal interests include skiing, cycling, ice hockey, and spending time with his wife, Allison (also a veterinarian), children Amelia and Ethan, their dog, Abby, and 5 cats.

It is our constant mission to find better ways to improve care, communication, financial support and service to our clients and patients.

As Oakland’s first Multi-Specialty and 24 hour Emergency Hospital, we strive to set the bar for Specialty and Emergency care by exceeding standards and expectations in customer service and patient care.  

Jamie Wignall

BVetMed (Hons), MS, Diplomate ACVS

Dr. Wignall comes from a family of veterinarians in the United Kingdom, and after pursuing veterinary school at the Royal Veterinary College in London, he returned home for a year in rural mixed animal practice. Adventure beckoned, and he completed his surgical training at Louisiana State University where he found a southern girl, a love for the New Orleans Saints and a terrier called Maverick. He then worked in Southern California for 4 years where the family expanded to add two more terriers, Biffy and Ziggy. His hobbies include snowboarding, soccer, hiking and spending time with his partner, Luli, also a veterinarian.

His professional interests cover all aspects of orthopedics, soft tissue, and neurosurgery, with a particular emphasis on the upper airway and minimally invasive surgery. Practice management has become a new interest and he is studying towards a Masters in Business Administration.

His professional interests include the application of minimally invasive surgical techniques (Arthroscopy, Laparoscopy, and Thoracoscopy) in the management of soft tissue and orthopedic disease, and the surgical treatment of cruciate disease, fractures, and Total Hip Replacement. 

Dr. Grange’s personal interests include skiing, cycling, ice hockey, and spending time with his wife, Allison (also a veterinarian), children Amelia and Ethan, their dog, Abby, and 5 cats.

It is our constant mission to find better ways to improve care, communication, financial support and service to our clients and patients.

As Oakland’s first Multi-Specialty and 24 hour Emergency Hospital, we strive to set the bar for Specialty and Emergency care by exceeding standards and expectations in customer service and patient care.  

John Haburjak

DVM, Diplomate ACVS

Dr. John Haburjak graduated from UC Davis Veterinary School in 1993 with his Doctor of Veterinary Medicine Degree. He practiced for 5 years before returning to academics to complete a combined surgical residency program in San Diego and the University of Illinois.

Dr. Haburjak is a Diplomate of the American College of Veterinary Surgeons his clinical surgical interests include surgical oncologic procedures of the face, head and neck, corrective orthopedic procedures, and disorders of the canine stifle. Finally, he has dedicated most of his post-graduate emphasis on minimally invasive procedures including: laparoscopy, thoracoscopy and interventional radiology (urethral and tracheal stenting).

Dr. Haburjak’s hobbies include singles tennis, Oakland A’s baseball, riding with his kids and cooking (not to mention eating, too!). He shares his life with his wife, Aimee (also a veterinarian), daughters Eva & Emery and sons Ian, and Isaac – along with Addison (bubble-headed Japanese spaniel), Poppy (a Cavalier King Charles Spaniel with a freckled nose!), Pixie (mutant Chihuahua) – some Guinea Pigs and a Cat named Ginger Cookie.

Internal Medicine

Benjamin Polansky

DVM, Diplomate ACVIM

Dr. Polansky is originally from Boston, MA where he earned his degree in Veterinary Medicine from Tufts University. It was during his internship at Louisiana State University School of Veterinary Medicine where he discovered a keen interest in the internal medicine specialty. He continued his training with an Internal Medicine residency at MedVet Medical and Cancer Center for Pets in Columbus, Ohio. Upon completion of his residency, he practiced at a high volume speciality hospital in southern California for the past four years.  Now Dr. Polansky is extremely excited for the opportunity to be part of the Oak Vet family. He has a particular interest in immune-mediated and gastrointestinal diseases, he values the human-animal bond, and is passionate in preserving and strengthening that relationship through medical intervention. 

As an active, outdoor lifestyle enthusiast Dr. Polansky enjoys hiking, running, and working out. He also loves exploring the area and spending time with his wife and daughter, as well as his two dachshunds. True to his northeast coast roots, he is an avid New England Patriots fan (Go Pats!).

Cardiology

Justin Williams

DVM, Diplomate ACVIM/Cardiology

Dr. Justin Williams completed his undergraduate degree at the University of California at Los Angeles before obtaining his veterinary medical degree in 2007 from Colorado State University.  He then completed an internship in small animal medicine and surgery at Wheat Ridge Animal Hospital in the Denver metropolitan area.  Dr. Williams finished a three-year cardiology residency at the MSPCA Angell Animal Medical Center in Boston, and earned board certification in cardiology from the American College of Veterinary Internal Medicine in 2011. Originally from Arizona, he enjoys the outdoors alongside his wife, Emily, and their three children. His hobbies include fly-fishing, hiking, photography, drawing, and ice hockey.

Emergency & Critical Care

Danielle Pollio

DVM, Diplomate ACVECC

Dr. Danielle Pollio graduated magna cum laude from the University of Georgia College of Veterinary Medicine in 2012. After veterinary school, Dr. Pollio completed a small animal rotating internship at Red Bank Veterinary Hospital and went on to pursue a three-year residency in emergency and critical care medicine at BluePearl Veterinary Partners in Tampa, Florida. She practiced at a large specialty hospital in the Pacific Northwest until moving to the Bay Area in 2020. Dr. Pollio is passionate about all aspects of emergency and critical care medicine and is particularly interested the treatment of polytrauma and sepsis. In her free time, Dr. Pollio enjoys jogging around Lake Merritt, baking for coworkers, and spending time with her husband and pets.

Erin Updegrove

DVM

Dr. Erin Updegrove graduated from the UC Davis School of Veterinary Medicine and pursued an emergency-focused internship outside of Washington, D.C. She has been practicing emergency medicine in the Bay Area since 2011. Outside of the ER, she is passionate about volunteering her time to underserved communities across the United States and internationally. Dr. Updegrove works with several organizations that provide free veterinary care for the public, as well as training for new graduate veterinarians and students. In her spare time, she enjoys gardening, hiking, and enjoying the Bay Area while sharing her home with an energetic pit bull named Riza.

Caroline Li

DVM

Dr. Caroline Li graduated from Ross University School of Veterinary Medicine and completed her clinical year at Oklahoma State University. She completed a small animal rotating internship at East Bay Veterinary Specialists and Emergency in Walnut Creek and has practiced in the San Francisco Bay Area since 2013, ranging from general practice, emergency and high volume spay neuter. Dr. Li has come full circle and returned to one of her first passions in emergency medicine and is proud to serve the Oakland/East Bay community. Outside of work she enjoys outdoor activities ranging from cross country skiing to training for triathlons. She shares her home with her “coconut retriever” Daphne and is owned by her two young cats Owl and Klay.  

Rachael Worden

DVM

Dr. Rachael Worden graduated from Auburn University College of Veterinary Medicine. After graduation she decided to follow her dream of moving to the West Coast and left her hometown in Northern Kentucky to pursue a small animal rotating internship in San Jose. During her internship she developed a passion for emergency medicine and elected to stay an additional year to complete an emergency focused internship. Dr. Worden recently moved to the East Bay to be closer to the city and surrounding microclimates. Dr. Worden is excited to continue practicing emergency medicine at Oakvet Animal Specialty Hospital and treat the pets of the Oakland/Bay area community. Outside of work she enjoys live music, snowboarding, hiking with her dog Milo, and exploring Northern California.

Josh Van Geem

DVM

Dr. Josh Van Geem is a Northern California native growing up in the foothills in beautiful Gold Country. As a second-generation veterinarian he has spent the majority of his life in and around veterinary hospitals and was fascinated by the quality of care veterinarians can provide for our beloved animal companions. Josh attended UC Santa Cruz for his undergraduate degree in Molecular Cell and Developmental Biology, during which he spent a semester abroad at the University of Edinburgh, Scotland in the medical sciences department. Following undergraduate he spent a year as a veterinary assistant/mentee at his father’s veterinary practice prior to attending UC Davis School of Veterinary Medicine for his veterinary degree. He went on to complete a small animal rotating internship at VCA San Francisco Veterinary Specialists and then worked in general practice in Oakland and Grass Valley. Josh enjoys the dynamics of veterinary practice and working with a diverse group of people for the sake of our animal friends.

Outside of work Josh is an avid musician (guitar, bass, trumpet, keys) and enjoys attending shows. Any given day you may find him cruising around on his bicycle in Oakland, San Francisco, or the North Bay or holed up at a café reading a book. He is sad that his miniature Australian Shepherd, Frankie, cannot be in the Bay Area with him (severe separation anxiety) but loves to go home to the foothills to his parents’ “Dog Ranch” where he and Frankie can go out to the river and appreciate nature. Now that the rigors of school and internship over Josh is looking forward to being able to travel abroad and get back into scuba diving.

Eric Nickerson

DVM

Dr. Nickerson was born and raised in Orange County, California. He completed his undergraduate studies at the University of California, San Diego where he studied Ecology, Animal Behavior, and Evolution. He spent a semester in Australia studying the biodiversity of the Great Barrier Reef. He also spent a year of research at the University of California, San Diego Medical School investigating the effects of hypoxia on gene expression and regulation in the brainstems of mice. He then attended UC Davis School of Veterinary Medicine to complete his DVM. While in veterinary school he received the national Dr. Jack Walther Leadership Award and represented UC Davis at the national level as a delegate of the Student American Veterinary Medical Association. He also completed research investigating the heritability of Subvalvular Aortic Stenosis (SAS) in Golden Retrievers, Newfoundlands and Rottweilers. He graduated with high honors and was inducted into the Phi Zeta National Honors Society. He then left for a rotating internship at Purdue University in Indiana with a specialized interest in cardiology and emergency medicine. He has a particularly strong interest in cardiac emergencies. In his free time, he enjoys traveling and hiking with his dog, Pebbles (who has mild SAS).

Sierra Edelsohn

DVM

Dr. Sierra Edelsohn is originally from the Bay Area, and graduated from Ross University School of Veterinary Medicine. Following this, she moved back to Northern California and completed a small animal rotating internship in Santa Rosa. She has always had a passion for surgery, and that year only served to strengthen her goal. She then went on to complete two Surgical Internships, the last of which was at a Level 1 Trauma Center in Buffalo Grove, Illinois. During her time there, she also had the opportunity to help out with the Shedd Aquarium, which included work with some sea otters and a porcupine. Her long-term goal is to complete a Surgical Residency, and in this effort, she also is currently participating in a Research Fellowship and gaining further experience with our surgical and ER departments. She is thrilled to be back with her family in the Bay Area, and treating the pets of her community. Outside of work, she loves live theatre, traveling, trying new recipes and relaxing with her cats, Polaris and Islay.