Acupuncture helps keep performance horses in top condition by creating analgesia, decreasing the risk of ileus, helping to prevent injuries, and much more.
According to a 2017 economic study by the American Horse Council, the US is home to over seven million horses. Roughly three million participate as performance horses, race horses and “work” horses.1 Complementary medicine therapies such as acupuncture can keep these equines in peak condition. It can also decrease the use of pain-relieving medications and joint injections, help with the ileus that may develop when traveling to shows, and prevent sports injuries.
Endogenous analgesia
It is imperative to understand the termination and synapsis of these fibers and nerves in order to conceptualize the release of endogenous analgesia, and how it relates to maintaining performance horses without added pharmaceuticals.
Endogenous opioids such as dynorphin and enkephalins, as well as adrenocorticotropic hormone, are released in the hypothalamus, and beta endorphin is released by the pituitary. Serotonin, dopamine and norepinephrine (NE) are neurotransmitters involved in both pre-and post-synaptic inhibition of central pain pathways, and aid in our patients’ “feel good” response during treatment. These neurotransmitters may also suppress the release of a neuropeptide called substance P, a neurotransmitter for nociceptive nerve terminals. Additionally, the hypothalamus releases acetylcholine (ACTH), stimulating the release of cortisol from the adrenal glands, which also may contribute to the anti-inflammatory effects of acupuncture.2,3,4
By decreasing inflammation in the body, providing endogenous opioids, and decreasing the effects of the pain pathway, we are consequently lowering the need for pharmaceuticals such as Phenylbutazone, Flunixin meglamine and exogenous steroids used in intra-articular injections.
Intra-articular injections come with associated risks including joint sepsis, flare, lack of effect, overuse and periarticular cellulitis, among others. In a recent clinical study involving intra-articular hock injection accuracy, published by the Equine Veterinary Journal, it was noted that the centrodistal (CD) joint was only 42% accurate, whereas the TMT joint was 96% accurate.4 This variation between accuracy leaves something to be desired.
Acupuncture can treat the whole body, in addition to having potent and consistent analgesic effects. It has been proposed that using acupuncture in conjunction with joint injections can decrease the frequency of needling intra-articular injections, which also decreases the amount of steroid administered into the body as well asthe associated risks with entering a joint. Acupuncture is a safe alternative to medication, and is accepted even at show side by the Federation Equestre Internationale.
Treatment of ileus
One of the unfortunate sequels that can happen when traveling to and from horse shows is ileus. Gastrointestinal motility can be broken down into three basic mechanisms. The first is neurogenic, and involves the intrinsic nervous system or extrinsic nervous system input causing changes in motility. The next mechanism is humoral, and includes neurotransmitters, polypeptides, and the non-adrenergic non-cholinergic nervous system. Finally, the myogenic aspect is associated with mechanical distention and reflexes of the intestines.6
Ileus can have several causes, such as paralytic (adynamic), spasmodic (dynamic), mechanical (obstructive) or idiopathic.6 As we know, acupuncture helps maintain a level of homeostasis throughout the body, and the external placement of needles has a direct impact on the associated internal visceral structures. To treat ileus in horses using acupuncture, one needs to perform a thorough DAPE/palpating exam, assess the animal’s yin constitution, determine which of the five elements are being affected, and finally assess deficiencies and excesses of Qi.6,7 Some acupuncture points beneficial for ileus include ST 25, ST 26, BL 20, BL 21, BL 25 and San Jaiung.2
Travel can cause added stress to horses, directly affecting changes in cardiovascular function, digestion, immunity and overall homeostasis. By performing acupuncture prior to travel, we can stimulate the parasympathetic nervous system to decrease many of these responses. Road transport and exercise were assessed in a recent study performed on five Thoroughbred race horses.8 Round one of the study was the “control”, and included transporting and racing the horses, then assessing glucose, lactate and erythrocyte osmotic fragility (EOF). The second part of the study involved performing acupuncture on the horses prior to transport and racing, then doing the same assessment. Performing acupuncture prior to transport and racing was shown to increase blood glucose, and reduce both lactate and EOF. These findings suggest that performing acupuncture prior to transport improves the horse’s physiological adaptation to stress and also enhances physical performance. 8
Acupuncture as prevention
Finally, acupuncture can be used as a preventative method for keeping equine athletes in top shape. As we know, horse owners are asking more of their performance animals, and are subsequently calling on acupuncture along with traditional Western medicine to help achieve these goals. The placement of needles into the appropriate points along the 12 paired meridians aids in the movement of Qi, decreases wind-up pain, treats myofascial trigger points, and creates homeostasis throughout the whole body.2
When working with performance horses, it’s a good idea to also assess the rider for imbalance; assess saddle fit; ensure properly shod hooves; and evaluate for mouth pain from sharp teeth or incorrect bit. These factors can all play a large role in performance-related problems that can cause subtle discomfort or pain, and should be addressed appropriately using whole-body acupuncture assessments and needle placement.2
Soft tissue back and neck pain are extremely common problems that affect performance and behavior. The back and neck are central to the musculoskeletal system, and directly change the horse’s movement, and the biomechanics necessary to carry a rider appropriately. For a horse to travel properly, his abdominal muscles, iliopsoas, tensor fasciae latae and quadriceps are all fully engaged, with the longissimus dorsi muscle relaxed to freely move the back and keep the hind legs engaged underneath the horse. Once his back loses its normal movement and flexibility, the distal limb must compensate for these changes in movement. For this reason, many believe that back soreness can cause distal limb lameness.2 When assessing back pain, performing a full body exam is recommended, with particular focus on assessing the bladder meridian for tension, trigger points, bracing, etc. Chiropractic care has been used in conjunction with acupuncture to aid in the health and proper function of the spinal column by returning spinal motor units to normal function.7 One should also contact the rDVM to discuss medication, joint injections, whole body pharmaceuticals used (i.e. Legend, Adequan, NSAIDs), and imaging. By incorporating each of these considerations into the treatment plan, we are setting these athletes up to perform and excel.
Acupuncture’s mechanism of action
Acupuncture works by targeting trigger points and specific locations along 12 paired meridians. These meridians course along neurovascular bundles throughout the body. The neurovascular bundles contain free nerve endings, an artery, vein, lymphatic channel and numerous mast cells.3,4 They are surrounded by a loose connective tissue sheath, which binds water and acts as an ion exchanger.
Additionally, acupuncture points are often located along the pathways of major peripheral nerves or their branches. At these acupuncture point locations, cutaneous nerves are emerging from deep fascia, bony foramina, at the bifurcation of peripheral nerves, or along tendons or ligaments. The insertion of small stainless steel needles stimulates these structures, and starts the healing cascade.
Multiple types of peripheral nerves throughout the body are targeted by the insertion of the acupuncture needles. We will primarily focus on A-delta and C fibers, sensory nerves that play a large role in the analgesic aspect of acupuncture. It is said that cutaneous nerves have more than a fourfold higher number of A-delta and C fibers when compared to A-beta fibers, which derive from cutaneous tactile receptors and endings of muscle spindles.2,3,4
Once a noxious stimulus affects the nociceptors associated with the A-delta or C fibers, transmissions of nervous impulses are sent to the dorsal horn of the spinal cord, activating the spinal cord, brainstem and hypothalamus, triggering release of neurotransmitters. The main functions of A-delta fibers are to carry mechanical and thermal pain, activating neurons of the neospinothalamic tract. These neurons have long axons that cross to the opposite side of the spinal cord, ascending to the reticular areas such as the brainstem and thalamus, sending signals to the somatosensory cortex, giving input as “fast-sharp” pain fibers. Comparatively, C fibers carry their information through the substantia gelatinosa, terminating primarily in the brainstem. These fibers are “slow-chronic” pain fibers that have poor localization properties.2,3,4
Acupuncture exam
When beginning an acupuncture session, it is important to obtain a thorough traditional history, PE and DAPE examination. A DAPE examination is derived from a traditional Japanese approach to acupuncture. Palpation is used to assess the whole body for trigger points, regions of pain, loss of sensation, change in range of motion, heat in areas of the body, and general pathologies.2
Conclusion
Equine acupuncture is a highly sought-after modality for keeping working and companion horses in top shape. It decreases the need for joint injections and medication by creating analgesia, decreasing wind-up pain, and releasing endogenous substances to directly affect the central and peripheral nervous systems. Additionally, acupuncture decreases stress during travel, aiding in digestion and decreasing the frequency of associated ileus. Finally, acupuncture is used as a direct assessment for overall body health and prevention of sports-related injury. By integrating holistic approaches such as acupuncture with Western medicine, we help keep our equine athlete patients in peak performance condition.
References
1Rizzo, Maria, et al. “Acupuncture Needle Stimulation on Some Physiological Parameters After Road Transport and Physical Exercise in Horse”. Journal of Equine Veterinary Science, Volume 48 , 23 – 30.
2“Economic Impact of the United States Horse Industry”. American Horse Council, 2017, www.horsecouncil.org/economics/.
3Boldt Jr., Ed., “Veterinary Acupuncture and Chiropractic: What, When, Who?” Am. Assoc. Equine Practitioner, 2016.
4East, Leslie M. “Equine GI Motility: Eastern Medicine Meets Western Medicine”. ACVIM 2002. www.vin.com/members/cms/project/defaultadv1.aspx?id=3845051&pid=8873&.
5Eckermann-Ross, Christine. “Mechanisms of Acupuncture Anagesia”. www.vin.com/Members/Cms/Project/defaultadv1.Aspx?Id=7546431&Pid=16051&, ABVP 2016.
6Crisman, Mark V. “Equine Acupuncture – Beyond the Qi Concept”. Proc. of ABVP 2012, Blacksburg, Virginia, Web. 1 Feb. 2017.
7Schoen A. Veterinary Acupuncture: Ancient Art to Modern Medicine. 2nd ed. Mosby; St. Louis, MO, USA: 2001.
8Seabaugh, KA, et al. “Clinical study evaluating the accuracy of injecting the distal tarsal joints in the horse”. Equine Vet J, 49: 668-672, 2017. doi:10.1111/evj.12667.
