Revolutionizing Equine Lameness
with Stem Cell Therapy
By Kimberly Rinker
The first-ever North American Veterinary Regenerative Medicine (NAVRM) Conference, held March 5-6 in Santa Ynez, Calif., brought together nearly 300 veterinarians and animal scientists working in the regenerative medicine and stem cell therapy fields.
The conference—sponsored by the University of California Davis Center for Equine Health, the Alamo Pintado Equine Medical Center and Rood & Riddle Equine Hospital of Lexington, Ky.—spurred the formation of the North American Veterinary Regenerative Medicine Association.
This association was formed in order to advance scientific and clinical applications of non-embryo-derived stem cell therapies and regenerative medicine techniques.
One of the attendees was Dr. Scott Hopper, DVM, MS, Dipl. ACVS, of Rood & Riddle. Dr. Hopper, a University of Wisconsin (DVM, 1993), Washington State University (Surgical residency, 1994-1997), and American College of Veterinary Surgeons, (1999) graduate, has been utilizing stem cells for both healing and regeneration in the equine athlete.
“Regenerative medicine is the process of creating living, functional tissues to repair or replace tissues or organ function loss due to injury, disease, age or congenital defects,” Dr. Hopper explained. “Stem cells are mother cells that have the capacity for both replication and diversification into other types of cells or tissues. These cells can be found in all different types of tissues throughout the body and in various phases of development. Muscles, skin, fat, brain, and bone marrow all contain stem cells and are different from other cells in that they can create progeny for repair of other cells.”
Dr. Hopper concentrates his research and clinical applications of non-embryo-derived stem cells using Mesenchymal stem cells, known for their ability to grow into connective tissue such as muscle and bone. These cells are obtained through various methods of collection—most notably from the hip of a young horse or from the sternum of an older individual.
“Stem cells are unique in that they can renew themselves for long periods of time through cell division,” Dr. Hopper said. “They’re a specialized cell that can be induced to become specialized tissue.”
Dr. Hopper cautioned that stem cell utilization is still in its infancy and further research is needed to understand the developmental process of stem cells.
“We have a stem cell lab at Rood & Riddle, and we try to educate people about the process,” he stressed. “Right now, I don’t want to create excessive hype for something we don’t have enough research on. It’s important for horse owners to know that we need to take baby steps in studying and quantifying our research of the use of stem cells.”
Dr. Hopper became interested in stem cell therapy after the birth of his three children.
“I have a five- and a three-year-old, and a child who is almost a year old,” Dr. Hopper offered. “When each of them were born, my wife and I made the option to store core blood from them, via umbilical cord storage, and that peaked my interest in potentially using stem cells in horses.”
The cost to collect and store human umbilical cord stem cells is $2,000, and the cells can be kept until a child turns 18.
“Just in the last year, with human core blood, doctors have been able to take those stem cells and induce them to act like embryonic stem cells. They’re markers on stem cells that show us they like to do certain things,” he said.
Stem cell therapy in horses began about five years ago, Dr. Hopper explained, but up until last year, he was the only veterinarian treating horses with it at Rood & Riddle.
“Stem cell use is in its infancy for both people and animals,” he continued. “Human doctors have used stem cells—most of which are blood harvested—to treat people, mostly children with leukemia. Now, human physicians are branching out in their treatments, using stem cells for things like brain injuries and Alzheimer’s disease.”
Dr. Hopper stressed that quantitative data regarding specific results from utilizing stem cells to heal and return a horse to the races is just not available yet.
“I get more inquiries asking about the therapy, than actually doing it,” he said. “The main point behind stem cell therapy is, do you get a better quality of healing? Well, no one has this data yet. It’s not out there. So it becomes difficult for me to say to an owner or a trainer, your horse has a 50 or 20 or 30 percent chance of recovery.
Dr. Hopper said he uses stem cell therapy primarily to treat soft tissue injuries, while applications in joints is not as prevalent.
“One of our biggest questions comes with bowed tendons,” he acknowledged. “With stem cells, most bowed tendons are going to heal, but the question is, will they re-occur? There’s already a surgery out there that significantly decreases the re-occurrence of a bowed tendon, so are stem cells a better option? Again, we don’t have the data to answer that question.
“First, you’ve got to be able to see a tear in the ultra-sound, because you need somewhere to stick the cells,” he explained. “We’ve treated horses that have done quite well and gone back to the races without a re-occurrence. But you could have two horses with identical tendon injuries and get varied results.”
Time also seems to be a factor in utilizing stem cells, Dr. Hopper noted.
“Another question is, if we treat the injury soon after it occurs, will that increase the chance of a stronger recovery?” he said. “The trend is to treat them earlier and treat them more than once. They may need to have a second or third injection for increased effect.”
Stem cells also affect and modify other cells around them, rather than actually changing themselves, Dr. Hopper explained.
“Some stem cells can differentiate into a number of things, while others have the ability to go to certain places within the body,” he stressed. “The potential for their use is endless.”
The 2011 NAVRM conference will be hosted in Lexington, Ky. by Rood & Riddle, and will incorporate a session for trainers, owners and breeders, Dr. Hopper confirmed.
“Our purpose with these
seminars is to have people involved in the development of this
research talk about their experiences, with the goal to
collaborate and put science behind their efforts.” 
