I’m sure that if your horse has had some sort of injury to, oh, just about anywhere, you’ve at least heard about the possibility of using “stem cells” to help speed/improve healing (not sure what you were told, you see). I’ve been following the research and information that’s being put out about stem cells with a great deal of interest (I write my first article about them in 2010, and you can read it if you CLICK HERE). The promise of stem cells – cells that can be injected into an area to help improve healing – is really exciting, because, quite simply, for many of the conditions that I see in the horsem and particularly those of the musculoskeletal system, my options are really very limited. It would be absolutely fantastic if there were a wonderful new option that could speed up healing, or, failing that, could improve the quality of healing so that the long-term outcome would be better.
NOTE 1: Please re-read the last sentence in the paragraph, above. I am completely in favor of any treatment that can be shown to do that.
NOTE 2: Please re-read the last sentence in the paragraph, above. LOTS of treatments claim that they can do just that. And most of them don’t have any evidence that they do. I am NOT in favor of claims that aren’t supported by evidence.
In the September 2014 issue of Equine Veterinary Education, a journal devoted to equine medicine and surgery, Dr. Ashlee Watts, of Texas A&M University published an article called “Use of Stem Cells in Equine Musculoskeletal Disorders” (pages 492 – 497). It’s a terrific review of the current state of knowledge, and it is designed to give equine practitioners a basic knowledge of the stem cells that are obtained from adult horses.
NOTE 3: In human medicine, lots of work has gone into embryonic stem cell research. Equine stem cells are not that. In horses, the amount of work on embryonic stem cells is essentially zero. It’s way easier to isolate and expand (grow) stem cells from adult tissues, which is probably why there are several companies out there doing just that.
Anyway, Dr. Watts goes on to note a couple of studies that have suggested some improvement after stem cell therapy, one on tendons (CLICK HERE), and one in stifles (CLICK HERE), but she also notes that there are situations where stem cell injections have NOT been effective, such as for osteoarthritis (CLICK HERE).
NOTE 4: The thing that’s a bit troubling about the positive studies is that they are using something called historical controls against which they measure their effects. The best scientific studies compare the intervention being tested against other horses that aren’t getting the intervention. Studies that use historical controls attempt to compare the results of horses receiving an intervention against horses that somebody else studied at some time in the past. Frankly, I was a bit surprised to see the studies using historical controls, because it’s long been known that using historical controls biases as study in favor of the studied intervention (CLICK HERE). Otherwise stated, if you use historical controls, you’re more likely to see a positive outcome for the thing that you’re trying to test.
Which is one reason why I don’t think much of those positive studies.
Anyway, if you’re thinking about having a stem cell treatment for your horse, I think that it’s really good to keep in mind Dr. Watts’ conclusions, which I quote here, with my own translation/interpretation, for your enjoyment.
DR. RAMEY – We don’t know what conditions benefit from stem cell therapy, how to best do it, how to best give it, what dose to give, when to give it, and how often to give it. Other than that…
DR. WATTS – “There are several factors that contribute to the lack of evidence.”
DR. RAMEY – We don’t really have any good evidence for the use of stem cell therapies in equine orthopedics but there are reasons for that. Not really excuses, per se… it’s hard, you know.
DR. WATTS – “First, most regenerative techniques are unencumbered by federal regulations…”
DR. RAMEY – You really don’t have any idea what you horse is getting with a particular stem cell therapy because nobody is checking and there aren’t any standards. Since nobody is checking and there aren’t any standards, people can pretty much do or say what they want.
DR. RAMEY – People are dumping them into just about anything.
DR. WATTS – “…by differing manufacturing processes…”
DR. RAMEY – Different companies have different ways to come up with stem cells. We have no idea what any of this means, however, since there aren’t any regulations.
DR. WATTS – “…and with differing treatment regimens.”
DR. RAMEY – Different people use them differently because there’s not any standard.
DR, WATTS – “Second, autologous regenerative products have differing compositions both between patients and even within the same patient from different collections.”
DR. RAMEY – The stem cells that you get from your horse are not necessarily the same as the stem cells from another horse. In addition, you don’t even get the same stem cells from your own horse when you collect at different times.
DR. WATTS – “Such widespread use of a variable product with variable treatment protocols makes it increasingly difficult to make sound conclusions.”
DR. RAMEY – I really have no idea what to tell you here. Lots of people are using stem cells, but nobody is really keeping track.
DR WATTS – “Based on the anti-inflammatory effects and the ability of stem cells to orchestrate tissue repair and regeneration via endogenous cell recruitment and production of trophic factors, early treatment and possibly repeated treatment may be advantageous.”
DR, RAMEY – Things are not necessarily hopeless, when it comes to stem cells.
DR. WATTS – “Continued experimental work and development of well controlled clinical trials will be paramount in deciphering the value and ideal treatment regimens of stem cell therapies for musculoskeletal disorders.”
DR. RAMEY – The only way that we’re going to know if all of this is really more than just a waste of time and money is if we actually do good studies and look.
So what does this new collection of information mean to you, a horse owner who absolutely wants the best for your horse, even if you have to take out a loan to do it? Depends on your attitude and inclination, I guess. If it were my horse, I wouldn’t use them at this point because:
- They’re expensive
- There’s no consistent product, and no product has been shown to be better than another. But mostly…
- They haven’t been shown to be superior to what we were doing before. In fact, some recovery protocols after stem cell injections into tendons are actually longer than what’s recommended for recovery without stem cell injections. (If you want to see a great rehab program for tendon and ligament injuries, advanced by Dr. Carol Gillis, formerly of the University of California, Davis, CLICK HERE.)
If you’re really looking to get a lot of information about stems cells, I’d recommend that you go outside of Google®, horse chat rooms, and company-sponsored websites, and take a look at the information provided by the International Society for Stem Cell Research (CLICK HERE). In particular, I’d take a look at their page, “A Closer Look at Stem Cell Treatments,” (CLICK HERE), and click on the the article, “Top Ten Things to Know About Stem Cell Treatments” (CLICK HERE).
Articles like Dr. Watts’ are sorely needed (in a lot of areas). They give a reality check on where we really are. If you think you’ve had good results with stem cells, then I’m happy for you, and even more importantly, I’m happy for your horse. But if you’re not persuaded to try them on your horse by the information that’s out there, well, neither am I, and you’re certainly NOT going to deny your horse an important therapy if you decide not to use them.