Acupuncture is an interesting treatment modality and one that is certainly controversial as the Western world has struggled to understand its mechanisms. Fortunately we have mostly gotten beyond whether it has an effect or not, and now focus on when to expect it to be applicable and how to properly select a regimen. While evidence that acupuncture was used over 3000 years ago in China on horses exists, the development of charts that accurately describe point locations for horses were devloped only about 30 years ago. Acupuncture points and the meridians on which they are located are the same as in people, but there are variations in location due to anatomical differences. Having an understanding of equine anatomy and physiology along with proper training in acupuncture are integral to successfully this modality. Dr. Frantz became certified in its use and diagnostic techniques 15 ago years through the International Veterinary Acupuncture Society (IVAS). This organization has been at the forefront as an educational body and has been instrumental in developing acupuncture charts and strictly adhering to acupuncure principles.
To answer the question of how it works depends on whether you want the Western or Eastern answer. Actually the Eastern explanation is easier to give and requires less of a grasp of physiology. Energy or Qi (pronounced Chi) flows through meridians, which are energy channels, and when an imbalance of energy develops then problems arise. Of course this is only a cursory definition as imbalances can involve many realtionships and the Yin-Yang realtionship is perhaps the most widely known. By selectively using acupuncture points the Qi is affected in an attempt to restore balance.
As one might gather, the Eastern definition while interesting does not satisy the more empirical understandings that are desired in the Western hemisphere. Therefore attempts have been made to develop experiments and methods to visualize "energy flow". First of all there is no way to visualize energy being transferred in the body, but we can visualize physiological processes. For example, since we know that stimulating a point can cause a reflex respone in the muscles associated with that area and we can also detect the presence of endorphins (opiate-like substances), cortisol and serotonin released from the brain, there must exist some method to allow these effects. Nerves are at the root of our Western understanding of how and why acupuncture works. A very powerful microscope (scanning electron microscope) has been used to see an acupuncture point in tissue. The point looked like a depression or vortex through which a nerve and vessels traversed. While we have no hope of visualizing or quantifying Qi we can at least accept that proper selection and stimulation of acupuncture points can have physiologic effects that can decrease discomfort, relax or stimulate muscles, decrease swelling and/or affect organ function. As opposed to commonly accepted medical treatments with medications the effects may not always manifest themselves as being as effective or reproduceable. So if we still have trouble understanding acupuncture and its efficay why is it used? Probably the best answer I can give is that it can work and more effectively treat some of the problems I encounter than commonly accepted medications.
In my practice I tend to use Acupuncture mostly for musculoskeletal problems such as muscle stiffness/pain, ligagment or tendon injuries and decreased performance issues. Rarely have I advocated its use for internal medicine problems such as heaves, colic or diarrhea. While there are potential benefits the time it takes to treat these type of cases is beyond the scope of my practice. I have successfully used it in the treatment of a dercease in appetite, skin growths and to alleviate post-colic problems.
When I work with a horse with a particularly sore back and/or muscle spasms acupuncture is generally recommended. I will often use it with chiropractic work as it helps to relax the soft tissues - muscles, tendons, ligaments - after adjustments are made. Neck issues and sacro-iliac pain are other areas where I find it particularly beneficial. For some horses under saddle or show anxiety can be successfully ameliorated with acupuncture. As a Veterinarian I have access to any number of medications, but I will use whatever is most likely to help me manage and or cure a problem and often acupuncture is the most effective treatment.