Our Mission

To advance the field of stem cell medicine, and bring its life‑changing treatments to pets everywhere.

The Gallant team is a collective of respected veterinarians, scientists, and some unbelievably dedicated entrepreneurs. Our work is the result of over 100 years of regenerative medicine experience, and a commitment to invest millions into the future of stem cell therapies.

The Gallant Team

  • Aaron Hirschhorn

    Founder: In Loving Memory 1978 to 2021
    As the founder of Gallant, Aaron Hirschhorn brought 20 years of experience operating, advising, and investing in technology companies. Inspired by the impact of regenerative medicine on his own life, Aaron founded Gallant in mid-2018. Previously, Aaron was the founder and CEO of DogVacay, a consumer marketplace app for dog sitting and dog walking. DogVacay raised $47m from investors including Benchmark Capital and Andreessen Horowitz. The business merged with Rover ( in April 2017 to create what is now a $1B pet services company. Outside of Gallant, Aaron was a Venture Partner at Bold Capital and previously served as a venture investor with Upfront Ventures. Prior to this, he worked at Monitor Group and Kayne Anderson Capital. He was on several private company boards, a member of YPO, an angel investor, and was a 2016 finalist for E&Y entrepreneur of the year. We are deeply saddened, and he will forever be missed. Gallant is determined more than ever to carry on his legacy, and we will remain true to his mission and vision.... Show more
  • Linda Black, DVM, PhD

    Chief Executive Officer
    Dr. Black started with Gallant in 2019 and served as President and Chief Scientific Officer before moving to Chief Executive Officer in April 2021. She brings over 17 years of cross-functional experience leading strategic and operational initiatives in the biotechnology industry. She has led corporate development, finance, operations, and R&D along with a track record in regenerative medicine – with extensive experience in the development and commercialization of stem cell therapies for pets. From 2016 to 2019, she served as President and Chief Scientific Officer at Medicus Biosciences, a preclinical biotech firm focused on using polymer technologies for localized drug and stem cell delivery. Prior to Medicus, she served as the VP of Product Development for VetStem Biopharma, the first veterinary stem cell company to provide regenerative therapies to horses, dogs and cats. She authored the first peer reviewed publications describing the safety and efficacy of primary adipose-derived stem cells in osteoarthritis and muscle injury in working dogs. This culminated with leading a product development team to develop the first “off-the-shelf “stem cell therapies for dogs with osteoarthritis, which was later licensed to Aratana. She was the founder and CEO of SciStem Therapeutics, a company focused on delivering off-the-shelf genetically modified stem cells for bone healing in pets and people. Prior to those roles, Dr. Black consulted exclusively for Merial, Ltd, now Boehringer Ingelheim Animal Health, supporting R&D, marketing, and sales divisions. She is a member of the scientific advisory boards of Medicus Biosciences and Zander Therapeutics, and a member of the board of Directors for Gallant. Dr. Black holds a DVM from University of Wisconsin-Madison, a PhD in Cell and Molecular Biology from University of Pennsylvania School of Medicine, and completed her post-doctoral fellowship at GlaxoSmithKline.... Show more
  • Carolyn Wrightson, PhD

    Chief Technical Officer
    Dr. Wrightson is a proven Chief Operating/Technical Officer with over 25 years’ successful leadership experience in scientific and technical operations, and research and development in the regenerative medicine, protein expression and genomic diagnostics industries for both human and veterinary markets. Excellent track record in partnering with top management and driving strategic value creation. Known for streamlining operations through reengineering and building highly skilled and motivated teams to deliver strong business results. Responsible for meeting growth requirements as well as assisting with strategic, regulatory, clinical, and scientific functions. Well versed in agency interactions from writing product characterization, manufacturing and controls technical section submissions as well as leading technical aspects of pre-approval and licensure audit inspections. Fiscally responsible mindset to develop corporate value in early-stage development process, build and communicate business acumen, foster collaboration and teamwork among staff through engagement and coaching to develop teams that deliver results. Known for working hand in hand with Quality staff to deliver safe and effective cell therapy products. Carolyn’s prior roles include COO/CTO of Performance Cell Manufacturing (Cellipont Bioservices, a cell therapy CDMO), as well as COO of VetStem Biopharma where she led laboratory operations and manufacturing development for 15 years, and as Group Leader at Sequenom for 7 years. Carolyn has received a dual B.S. in Biology and Biochemistry from Mount St. Mary’s University, earned her Ph.D. in Pathobiology from the University of Southern California, and completed her post-doctoral fellowship at The Scripps Research Institute department of Molecular and Experimental Medicine.... Show more
  • Beau Becker

    Sr. Director of Operations
    As a founding team member of Gallant Therapeutics, Beau brings over 10 years of operational experience in the pet space and has been a part of teams from seed rounds to public. Prior to the founding of Gallant, Beau lead consumer operations for Pod Trackers, a GPS tracker for dogs and cats with customers in more than 150 countries. While at Pod, Beau ran international logistics and specialized in optimizing the customer experience while working cross-functionally with the engineering team to develop a top trier tracking device. Before that, Beau was Sr. Customer Service Manager at DogVacay, a consumer marketplace app for dog sitting and dog walking where he managed a team of 30 customer service and ops representatives that helped set the standard for customer service in the pet space. The business merged with Rover ( in April 2017 to create what is now a public $1B pet services company. Under Beau’s leadership, the team was able to successfully transition Dog Vacay’s more than 300k customers to the Rover platform. Beau welcomes the challenges of building a company from the ground up along with all the challenges and opportunities to learn new skills. In his free time, he enjoys spending time outdoors with his pups Chiquita and Autzen and rooting for his Alumni mater University of Oregon Ducks.... Show more
  • Mark Hughes, DVM, MS

    Vice President of Regulatory & Clinical Development
    Dr. Hughes brings over twelve years of experience in product development, preclinical/clinical studies and regulatory affairs for companion animal therapeutics. He has managed or contributed to clinical studies and regulatory submissions on the safety and effectiveness of veterinary drugs for therapeutic treatments related to dermatology, cardiology, endocrinology, oncology, osteoarthritis, and infectious diseases. From 2008 to 2016, Dr. Hughes served as a product development manager at Virbac, a major animal health company, leading international project teams in developing new drug products and obtaining regulatory approval for the products in the USA and Canada. From 2016 to 2018, he managed clinical studies and prepared regulatory submissions for VetStem Biopharma in support of the company's regenerative medicine product development program for companion animals. In early 2019, Dr. Hughes started Hughes Veterinary Consulting, providing consulting services for US and foreign companies seeking FDA approvals for new animal drugs. He presents two-day seminars on the Veterinary Drug Approval Process at locations across the US and Europe. Dr. Hughes earned BS, MS, and DVM degrees from University of California Davis and gained extensive academic research experience in a three-year post-doctoral fellowship in Comparative Pathology at UC Davis.... Show more
  • Shelly Zacharias, DVM, MS, VPM, BCMAS

    Vice President of Veterinary Affairs
    Dr. Zacharias brings ten years of multifunctional and clinical leadership experience in the field of stem cell therapy research and development plus 14 years as a clinical small animal veterinarian. She has extensive experience in the scientific development and business operations of a start-up biotech, led corporate efforts, R&D, clinical trials, and has considerable experience in regulatory compliance. In 2010, she co-founded a veterinary biotech company, Renovocyte, that made strides in stem cell therapy development in metabolic diseases in dogs and cats. In 2013, she was involved in the sale of the company to a global human medical company, Cook Group, Inc, where she remained an integral member of the executive leadership team as the Director of Veterinary Operations. At this time, she led the company into a partnership with a global animal health company where positive data was generated in continued stem cell studies in dogs and cats. In 2019, she was again involved in the acquisition of the veterinary stem cell R&D company by Gallant. Dr. Zacharias manages external professional relationships, interacts with medical doctors and veterinarians in a translational medicine aspect, and has experience conducting clinical trials. She was instrumental in the development of a new “off-the-shelf” cell therapy drug for metabolic disease which she has been working toward FDA approval. Shelly holds a Bachelor of Science in Biochemistry from Cameron University as well as a Master of Arts in Secondary Science Education and a Doctor of Veterinary Medicine from the Oklahoma State College of Veterinary Medicine. She holds a certification in veterinary practice management (VPM) from Purdue University and has completed graduate-level studies in endocrinology prior to veterinary school. In 2020, she completed the board certification for a medial affairs specialist (ACMA).... Show more
  • Darryl Rawlings

    Board Member
    Darryl Rawlings has established himself as a leader in medical insurance for cats and dogs. As founder and chief executive officer of Trupanion and founder and member of NAPHIA, Rawlings is setting high standards for a growing industry, expanding public awareness of medical insurance for cats and dogs, and expanding the market across North America. His passion for pet health runs deep. When he was 14, his family dog needed surgery that could have lengthened her life for another 12 years. The cost was beyond his parents’ means and they left the veterinary hospital without her. He vowed that someday pets would have even better medical insurance than people do. And Trupanion has fulfilled that promise with medical insurance for cats and dogs that is remarkably better than most human health insurance. Trupanion covered its first pet in Canada in 2000 and expanded to the United States in 2008. Since expanding to the U.S., Trupanion has established itself as a market leader and now provides medical insurance for cats and dogs in the United States, Canada, and Puerto Rico. In July 2014, Darryl took this a step further, and lead the company through an IPO. Trupanion is publicly traded on NASDAQ. Under his leadership, the company continues to experience consistent growth, with revenue growth in excess of 25% in each of the past 39 quarters. Trupanion now covers more than 500,000 pets. Rawlings is a graduate of the British Columbia Institute of Technology. His family includes his wife Caroline, two sons Sam and Bennett, bulldogs Tristen and Priscilla, cat Halle and bird Q.... Show more
  • Richard D. Jennings

    Board Member
    Richard Jennings is the CEO of California Cryobank Life Sciences and brings a wealth of knowledge and experience in the biomedical and healthcare fields. He joined the company in 2008 and served as the President of the Stem Cell division before being named as CEO. Prior to joining California Cryobank, Richard served as CEO of Mediscan, Administrator of CFHS Holdings (Hospitals), and held leadership positions in R&D and Marketing at Kimberly Clark Corporation. He earned an MBA from Harvard Business School and Bachelor of Science degree in Chemical Engineering. Richard is additionally a Board Member of Palisades Country Estates and Village School. He supports various fund raising efforts including the Leukemia & Lymphoma Society.... Show more
  • Robert W. DiMarzo

    Board Member
    Robert W. DiMarzo is a successful, global animal health executive with over 30 years of leadership and management. From building and salvaging businesses, strategic planning, tactical operations, regulatory strategies, manufacturing, distribution, licensing, marketing, including pharmaceutical sales. Roberts has a deep love for companion animals, and profound understanding of equine and livestock animal health sectors. He’s an expert in diverse global markets, knowledge of industry drivers and advancement for the future. His entire value chain has guided him to successfully generate exponential growth, from start-ups backed by Venture Capital and Private Equity to large public companies. Roberts extensive experience has provided him a unique perspective on how to be successful in an unpredictable and complicated global industry. Known for decisive leadership, and team building that thrive on opportunities for new products and technologies. His career began with Elanco, an animal health division of Eli Lilly, in marketing and new product launches then later advanced to Pfizer Animal Health (now Zoetis). During his tenure, he held several positions, such as, Senior Marketing Manager for new products and global launches, Marketing Manager in Brazil, and Division Director in Italy. Finally, progressing at Pfizer as President of Operations, he was responsible for the entire animal health sector. The U.S. Division gained a reputation as THE industry leader in creative strategy implementation, innovation, and outstanding marketing/sales policies which grew to over $1 billion in revenue. Before Robert embarked in the animal health industry, he was a U.S. Naval Officer in the Pacific Theater and northeast of the U.S.A. He also volunteered in the Peace Corps for the Central African Empire/Central African Republic. Graduating with an MBA from Harvard University and BSc from Brown University, he also fluent in French, Italian, Portuguese, Spanish and Sango. Some hobbies include traveling, new cultures, global “futebol”, lacrosse, military affairs, reading, mentoring, AND avid cycling.... Show more
  • Art Antin

    Arthur J. Antin is the co-founder of VCA, Inc., the largest family of animal care providers nationwide. Since its establishment in 1986, VCA has expanded its operations to include 923 hospitals in 46 U.S. states and five Canadian provinces. It also provides diagnostic services to more than 17,000 independent hospitals, supplies high-tech imaging, and now offers doggy day care and boarding at over 168 locations. Antin has served as VCA’s Chief Operating Officer, Senior Vice President, Secretary and Director. While the company was sold to Mars, Inc. in 2017, Antin continues with VCA as a Senior Advisor working on the company’s expansion into emerging markets in Brazil and Japan.
 Prior to VCA, Mr. Antin worked as an educator for eight years in Yonkers, NY. He then served as Director of Marketing/Investor Relations of AlternaCare Corporation, where he developed and implemented marketing strategies for a network of publicly traded outpatient surgical centers. Antin received his AA from Bronx Community College in 1967, BA from City College in 1969, MA in Community Health from New York University in 1973 and Certificate in Computer Programming from Columbia University in 1982. Today, Antin serves on the Board of Directors of the Boys and Girls Club of Santa Monica and Western University in Pomona, CA. He lives with his wife, Pat, in Santa Monica, CA, where he enjoys playing golf and cycling.... Show more
  • David Haworth DVM, PhD

    David Haworth is former President of PetSmart Charities in the US and Canada. An independent non-profit, strategic grant-making organization, PetSmart Charities seeks to end pet homelessness by supporting partner organizations and programs that help find loving homes for all pets and celebrates the bond between people and animals. Dr. Haworth was formerly President & CEO at Morris Animal Foundation, Director of Global Alliances within the Business Development group at Pfizer Animal Health (now Zoetis, Inc.), and before that a Director in Pfizer Animal Health's Research & Development division. Prior to joining Pfizer Animal Health, he was an associate veterinarian at a small animal and emergency clinic in Washington State. Dr. Haworth received his bachelor of science in biology from the College of William & Mary and his doctor of veterinary medicine and doctorate of philosophy from Colorado State University. He also completed a postdoctoral fellowship at Colorado State University's Flint Animal Cancer Center.... Show more
  • George "Bud" Scholl

    As President and Chief Executive Officer of OneBlood, George “Bud” Scholl brings diverse experience and knowledge to Gallant from positions as a healthcare executive, entrepreneur, developer, technology expert, asset manager and turnaround specialist. Prior to the OneBlood, Bud served as chief executive officer of Community Blood Centers of Florida, a position he assumed after serving on the board of directors for ten years. An entrepreneur for more than thirty years, Bud developed a landmark mixed-use medical office building in Coral Gables, Fl. Bud’s civic engagement includes his current role as Mayor of the City of Sunny Isles Beach. For seven years prior to his election as Mayor, he served as a City Commissioner. Bud was a member of the IT and Telecommunications Committee of the Board of Commissioners of Broward Health, one of the five largest hospital districts in the United States. His eight year tenure included overseeing telecommunications, IT planning, integration and systems purchasing for the public hospital district. Bud is a graduate of the University of Florida and holds an engineering degree in computer science.... Show more


  • 'Shark Tank' recap: Sharks growl over cost of cutting-edge science for man's best friend

    USA Today
  • Animal biotech company opens first pet stem cell bank it claims can help man's best friend live healthier for longer

    Daily Mail
  • Stem Cell Banking For Pets Means Fighting Illness in the Future

    Pet Guide

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