Arista Advanced Pet Care Welcomes Dr. Nick Berryessa as Internist and Owner at Atlanta Hospital

Arista Advanced Pet Care, a veterinarian-founded multispecialty referral and emergency hospital group, announces that Nick Berryessa, DVM, DACVIM, has joined its Atlanta hospital as a board-certified veterinary internist and owner. A longtime Atlanta-area veterinarian and Roswell resident, Dr. Berryessa brings nearly two decades of experience in internal medicine and advanced diagnostics to Arista Atlanta, located at 5525 Interstate N Pkwy in Sandy Springs.

Dr. Berryessa specializes in the diagnosis and management of complex medical conditions, with particular interests in endocrinology, infectious disease, respiratory conditions, ultrasound, and interventional procedures.

“Nick brings exactly the combination of clinical expertise, collaboration and local perspective that we envisioned when building Arista,” said Jennifer Welser, DVM, DACVO, President of Arista Advanced Pet Care. “He has spent years building relationships with veterinarians throughout Atlanta and understands what they and their clients need from a specialty partner. His experience, reputation and commitment to collaborative medicine make him a strong addition to our Atlanta team, and we are thrilled to welcome him as both a member of our medical team and an owner who will have a meaningful voice in how we continue to grow and serve this market.”

Originally from San Jose, California, Dr. Berryessa earned his bachelor's degree from the University of California, Davis, and his Doctor of Veterinary Medicine from Cornell University before completing his residency in Small Animal Internal Medicine at UC Davis. He first came to Atlanta for an internship at a large emergency and specialty hospital, where he met his wife, Jennifer, a veterinary neurologist. The couple ultimately returned to the area, where Dr. Berryessa has practiced since 2008.

Most recently, Dr. Berryessa has operated his own veterinary telemedicine and consulting business, providing ultrasound consultations for veterinary practices. He currently interprets approximately 300 ultrasound cases each month, further deepening his expertise in diagnostic imaging and complex case evaluation.

“What stood out to me about Arista was the culture and the opportunity for the veterinarians providing care every day to have a real voice in how the hospital operates,” said Dr. Berryessa. “Arista integrates local decision-making, veterinary ownership, and the operational support needed to run a successful hospital. It allows us to focus on providing great medical treatments and patient care while still allowing us to shape the practice we want to build.”

Dr. Berryessa is particularly passionate about multifaceted internal medicine cases, including patients managing multiple conditions, and brings experience with advanced interventional procedures such as tracheal and urethral stent placement. He is also committed to maintaining close communication with referring veterinarians throughout a patient's care.

“Many of our clients have entrusted their primary veterinarian with multiple pets, for years, so that relationship is incredibly important,” said Dr. Berryessa. “When a patient is referred for specialty care, I want to keep their veterinarian updated on the diagnostic and treatment plan and make sure that they are part of those decisions. That collaboration helps all of us to provide a better experience for the pet owner.”

Arista Atlanta opened in Sandy Springs in April 2025 as the company's first specialty and 24/7 emergency hospital, offering Internal Medicine, Surgery, Oncology, Emergency, and Critical Care and I-131 radioactive iodine therapy. Arista's model gives specialists the opportunity to become owners in their hospital while providing the infrastructure and operational resources of a larger organization. Although only opened for a little over a year, the Arista Atlanta hospital has already been awarded Best Emergency Veterinarian of 2026 by My East Cobb, My Dunwoody, My Sandy Springs, and bestself.

“Atlanta has been my home for nearly two decades, and I’ve had the opportunity to build relationships with so many veterinarians and pet owners throughout the area,” said Dr. Berryessa. “I’m excited to be part of Arista’s future here and to help make advanced specialty care more accessible to pets and families across the Atlanta area.”

Dr. Berryessa is board-certified by the American College of Veterinary Internal Medicine and has authored and contributed to research on infectious disease and other complex medical conditions in companion animals.