Why Equine Acupuncture is Gaining Ground - A look at the research
National Geographic released a minidocumentary, “Treating Animals with Acupuncture,”1 in early 2016. The video highlighted veterinarians learning acupuncture from one of the long-term equine practitioners in the field, Dr. Kevin May, who stated in the interview: “As far as the things we treat most often, [those] are the things that respond the most. So musculoskeletal problems, pain, nerve damage. … Acupuncture stimulates the body to heal itself. [That’s] pretty much it in a nutshell.”
A growing number of veterinary schools offer equine acupuncture in their teaching hospitals, including Colorado State University, the University of Illinois and the University of California, Davis.
Illinois assistant professor Kara Lascola, DVM, MS, Dipl. ACVIM, in a recent issue of The Horse discussed opportunities for healing that acupuncture brings to her patients. She stated, “I mainly use acupuncture to help manage chronic pain associated with musculoskeletal problems, such as back injuries, although it can also be used in management for other conditions, such as laminitis or neuropathies.”2
Further, she described the improvements she witnessed in an equine patient diagnosed with chronic back pain when acupuncture was added after corticosteroids and shockwave therapy failed to produce sufficient improvement.
Effects of Hippotherapy
In addition to treating horses used for pleasure riding and performance, acupuncture can provide significant benefits for those working in therapeutic riding centers. Horses involved in hippotherapy experience their own stresses and strains, and they must compensate for the added impact of the non-equestrian rider who may have physical, cognitive or emotional dysfunction.
Many of the human participants in hippotherapy sessions have disorders of movement. Over time, these children or adults may show improvements in posture, balance, mobility and sensory processing.3 However, this work can take a toll on the horses. Bearing the weight of an imbalanced and potentially unyielding rider means they have to continually adapt to unevenly distributed forces.
Can acupuncture help these horses? A research review from 2012 reported that over 4,000 U.S. veterinarians practice acupuncture.4 The authors found over 10,000 English-language papers pertaining to acupuncture science and theory, with nearly 300 specifically related to veterinary medicine.
They wrote, “Despite the challenges inherent in designing clinical trials for acupuncture (e.g., difficulty blinding a study and standardizing a single treatment for all animals in a group), research supports the use of acupuncture as a safe and effective treatment for many disorders in animals.”
Regarding musculoskeletal pain, particularly in performance horses, the authors stated that clinical trials involving electroacupuncture (EA) “provide clear, scientifically based evidence that three sessions of EA treatment can successfully relieve signs of back pain in horses and the analgesic effect can last two weeks. In contrast, medicating with oral phenylbutazone alone did not effectively relieve pain.”5
What One Study Found
Since that review, more research has emerged. A 2016 study published in Veterinary Anaesthesia and Analgesia compared the effects on lameness of three acupuncture treatments over eight days to no treatment.6 Two board-certified surgeons, blinded as to treatment status, reviewed videotapes of the horses moving. Results showed that acupuncture reduced hip hike differences under all conditions and led to other objective and subjective improvements as well.
Of course, not all equine acupuncture studies reveal positive results, just as studies on drugs and surgery are not uniformly positive. This does not mean the treatment itself is invalid, but instead causes us to question whether the methodology is faulty, the numbers are too low7 or if acupuncture is inappropriate for the condition in question.
No Gallbladder in Horses
Another challenge facing equine acupuncture pertains to misleading nomenclature. One paper described the analgesic effects of needling local and distal sites along the lateral aspect of the horse where both bipeds and quadrupeds frequently exhibit myofascial dysfunction.8 In acupuncture parlance, this linear and often tender connective tissue route corresponds to the “gallbladder meridian,” as denoted in humans. However, horses have no gallbladder.
Furthermore, while acupuncturists who practice Traditional Chinese medicine have adopted the term “meridian” to describe the acupuncture pathways, the word “channel” serves as a more accurate translation of the Chinese term “jing-luo,” connoting correspondence to nerves and vessels, not mysterious energy routes.9
By recognizing the neuroanatomic basis of acupuncture, we can take that information—i.e., that acupuncture works through a process known as neuromodulation—and design needling protocols capable of helping normalize nerve function, balance autonomic tone and relax both body and mind. However, extrapolating the human acupuncture point matrix onto the equine form poses several challenges that call for careful anatomic research.
First and foremost, the distal limb of the horse differs dramatically in both form and function from the human. As such, several sets of points located on four out of five digits on the human hand and foot have no comparative location in the horse.10 This limits veterinarians’ ability to extrapolate and test comparative locations across species and requires a fresh approach to point location and nomenclature.
Other challenges posed by anatomical variations involve paraspinal points identified by their vertebral locations. The equine thoracic spine has six more vertebrae than does the human, leading to a curious placement of points seemingly determined by convenience of needling rather than actual neuroanatomic relevance.11 These points that closely parallel the spine exhibit somatovisceral and viscerosomatic relationships to internal organs by dint of crosstalk between somatic and visceral interneurons within the dorsal horn of the spinal cord.
Precise mapping of autonomic nervous system and internal organ networks in the thoracic and lumbar spinal cord of the horse would greatly improve the reliability of treatment effects associated with acupuncture on the equine back.
Moreover, as stated by the author in the article ”One Medicine, One Acupuncture,” “Reconciling inconsistencies [between human and non-human acupuncture maps] will bolster the ability for researchers and clinicians to better understand and interpret findings from acupuncture studies on various species so that more can benefit from these insights.”12