Our Team of Specialists

Dr. Mark Walker originates from Auckland, New Zealand and obtained his veterinary degree from Massey University. After graduation, Dr. Walker worked in a referral hospital in Liverpool, England UK assessing referral and primary accession cases. Returning to New Zealand, he worked as a junior lecturer in Internal Medicine with a focus in gastrointestinal disorders under the tutelage of world-renowned, veterinary gastroenterologist Dr. Grant Guilford. Dr. Walker was awarded the Small Animal Medicine Chapter Prize, Australian College of Veterinary Scientists, and became a member of the Australian and New Zealand College of Veterinary Medicine. Dr. Walker furthered his training at the University of Florida where he successfully completed a Residency in Small Animal Internal Medicine and became a Diplomate in the American College of Veterinary Internal Medicine. Following his residency training, Dr. Walker worked in research in gene therapy. His efforts led to the successful application for two NIH grants to develop a novel therapy for both cats with anemia and later a gene therapy treatment for an infantile cardiomyopathy in children (Pompe’s Disease). Dr Walker worked as an associate veterinarian until 2012 when he founded a specialist veterinary referral hospital. During his career, he has received numerous awards including The Florida Veterinary Medical Association Certificate for Patient Care and the FVMA’s Continuing Education and Ethical Code Award on five occasions. He also received the FVMA’s Gold Star Award for service to Veterinary Medicine in the State of Florida.

Dr. Mark Walker has twenty-seven, peer-reviewed publications and continues to present lectures at national conferences. He has been invited to review manuscripts for the Journal of Veterinary Internal Medicine (JVIM). He has also authored chapters in Slatter’s Textbook of Small Animal Surgery, The Feline Patient (4th edition), and the Five Minute Veterinary Consult (2nd and 3rd editions).

While Dr. Walker has an interest in all aspects of veterinary internal medicine, he particularly enjoys the diagnosis and management of complex medical disorders. Dr. Walker is married to Dr. Olga Walker and they have five children, four cats and two dogs. In his free time, Dr. Walker enjoys spending time with his family.

Dr. Walker is excited to embark on a new chapter as a founding member of Nassau Veterinary Specialists. Along with Dr. Linden, Nassau Veterinary Specialists (NVS) will proudly serve North Florida and South Georgia.

Dr. Linden obtained his veterinary degree from Ross University School of Veterinary Medicine. Post graduation, he pursued a rotating internship in small animal surgery and medicine at Louisiana State University. Upon completing his internship, Dr. Linden was accepted into a surgical residency program at Auburn University. During his residency, he obtained a masters degree in biomedical sciences. With a strong interest in oncology, he became a surgical oncology fellow at Auburn University. During his fellowship, he gained a strong background in integrative oncology, working with a team of surgical, medical and radiation oncologists.

He obtained board certification in surgery in 2018. Upon completion of his fellowship and publication of his research, he was granted the status of ACVS Fellow in Surgical Oncology in 2019. After moving from Sarasota in 2021, he has been serving Jacksonville as the only surgical oncologist in Northeast Florida and Georgia.

His interests and research areas include lymphatic metastasis, head and neck cancers, as well as oral and maxillofacial surgery. He has extensive training in oral cancer, focused on mandibulectomy and maxillectomy techniques.

Dr. Linden currently serves on the editorial review board for Veterinary Surgery and reviews research manuscripts for journals including Veterinary Comparative Oncology, Journal of American Veterinary Medical Association and Journal of American Animal Hospital Association. He has contributed to numerous publications for prestigious journals, textbook chapters and is a serving member of the ACVS Fellowship committee for surgical oncology. Dr. Linden is proud to be one of the only surgeons in Northeast Florida offering sentinel lymph node mapping, as well as lymphatic and tumor mapping with Near-Infrared technology to ensure the best possible outcomes for patients with cancer.

Dr. Linden shares his home with his wife, two kids, two dogs and three cats.