Future stem-cell uses

"There are some encouraging aspects to this technology, but definitive proof of efficacy is still lacking," says Fortier. "There are still gaps in our knowledge, although the technology is developing rapidly."

"There is a client-based use for stem cells," Peroni says. "People have learned we have this treatment modality for the horse and request it. One of the good things (about stem-cell therapy) is that there really aren't any down sides.

"We're starting to see more people asking for this therapy, because they've become familiar with it through the media," says Garcia-Lopez. "For the joints, I'm still very cautious. It just depends on the condition. For instance, for horses with end-stage arthritis ... obviously I don't think you can just inject stem cells and have a horse recover. You might give it relief for a short period, but it's not as if you are regenerating cartilage. But for some soft-tissue injuries, for some cysts, we are definitely more comfortable using it (stem cells) as a viable alternative. ... As an adjunct to other therapies, I think it is going to be very effective."

"Stem-cell regenerative medicine is on the horizon, so a basic understanding of stem-cell biology is important for surgeons," Fortier says.

"Although there are several exciting studies suggesting the existence of stem cells in adult tissues and the ability of these and ES cells to transdifferentiate across tissue lineages, indisputable in vivo data is lacking. Studies need to be carefully evaluated; biologics advertised as "stem-cell therapies" should be closely scrutinized before clinical application. Still, the potential benefits of stem-cell transplantation ... are limitless," says Fortier.

"There are still so many questions. Maybe two stem cells are enough in some cases and we don't need 200. Do you start turning them into tendon tissue before you put them into the horse? I think we'll answer a lot of these questions. Perhaps in 20 years we can simply call on the resident pool of stem cells and without taking anything out of the body just figure out a way to call them into action."

Kane is a Seattle author, researcher and consultant in animal nutrition, physiology and veterinary medicine, with a background in horses, pets and livestock.