Is acupuncture good for pain in horses?

Edward Busuttil discusses the many benefits of acupuncture for your horse and how it can help to reduce pain

Acupuncture involves the insertion of sterile, single-use needles, into specific points in the body, tasked with stimulating a number of responses. So, how does acupuncture work and, how can it help horses.

History of acupuncture

Acupuncture is a technique that was developed and has been used in China over the last 2500 years. The theories behind it were created through trial and error and combining different ideas. There was no scientific basis, which initially and understandably, made its practice undesirable in the Western world. This started to change in 1970, when the then US President Richard Nixon was on a presidential trip to China and was impressed with his first-hand impression of the efficacy of acupuncture. This resulted in the start of clinical trials and scientific study into how it actually works, and its effects on the body.

 

A basic understanding of the body’s response to pain

Understanding how the body responds to pain is essential in beginning to understand how acupuncture works. When a painful stimulus affects the body, the nervous system carries this information as electrical signals to the brain, where they are processed, and an appropriate response is then carried out by the body. Two things happen:

• An instantaneous motor response. The animal pulls away from whatever is causing discomfort or, adjusts its gait or carriage appropriately so as not to exacerbate it.
• A delayed response, which results in the release of inflammatory cells and hormones to help to decrease the inflammatory pain and, improve circulation to the area.

An example is if your horse was galloping in the field, made a quick turn and twinged a muscle in its back. That initial pain sensation is carried to the brain, which tells the muscle to spasm to decrease the risk of more damage; the animal will be more reluctant to use that muscle, which would then affect its movement. Over the next few days, cells and hormones work to increase blood flow and decrease the inflammation locally, to improve healing.

If the horse continues to exacerbate the problem, by being overworked (more schooling) or not taking care of itself (running around in the paddock), it will take longer to heal and result in compensatory issues, as other parts of the body have to pick up the slack of the affected region.

Systemic (injections or oral) pain relief can be extremely beneficial in decreasing the inflammation, and appropriate treatment (duration, dosage and potential side effects) should be discussed with your vet.

Effects of acupuncture

Insertion of acupuncture needles has been shown to increase the blood concentration of opioids) and serotonin), as well as provide positive changes in markers which decrease inflammation and restrict breakdown of cartilage³. Therefore, acupuncture helps to systematically decrease pain (opioids), improve the patient’s mood (serotonin), decrease inflammation (including pain and swelling), and slow down degenerative changes.

The acupuncture points are found in areas of low electrical resistance and high electrical conductance⁴, meaning that these areas are extremely well linked to the same nervous system that carries the electrical signals to the brain. 80% of the points are at sites of connective tissue within or between muscles⁵. At these points, there is a large collection of nerve endings, blood vessels and mast cells⁶.

After the needle has been inserted, it is stimulated through twisting and re-positioning, resulting in winding of the connective tissue⁷, which in turn causes long term changes within its structure). Trauma to the area also increases local blood flow, and therefore there is a better nutrient and oxygen supply to the area, improving healing.

Other modalities of acupuncture include electro-acupuncture and moxibustion

Electro-acupuncture

This involves the attachment of crocodile clips to link 2 acupuncture needles. A current is then passed through the circuit, resulting in continuous stimulation at a set frequency and intensity, increasing the efficacy of the treatment.

 

Moxibustion

This involves the burning of the moxa herb in very close proximity to specific acupuncture points. Like acupuncture, it has also been shown to reduce clinical signs of people with rheumatoid arthritis by decreasing inflammatory mediator levels in the blood⁹ ¹⁰. This research is fairly new (2020) and questions whether some of the degenerative changes can be reversed due to the decreasing levels of the substances in the blood which damage the joint, however, a lot more research is needed before this can be confirmed.

 

Figure 3: Moxibustion – Moxibustion involves the burning of mugwort in close proximity to an acupuncture point or an inserted needle – it has been shown to increase inflammatory markers and opioids locally and in the blood, when applied in the right spot

But does that actually make a difference to pain levels? ¹¹

In 2020, the Clinical Journal of Pain published an article that compared 21 studies, which were meticulously screened to ensure that the studies performed were of a high enough quality. They looked into whether a placebo effect was present, meaning, did the patient feel better because they had been treated or, because treatment had actually been successful.

Simply put in each study, half of the patients received proper acupuncture treatments, and the other half received ‘sham acupuncture’, meaning that the needles were either inserted into the areas which were not acupuncture points or, acupressure was performed instead. The patients did not know which group they were in. The patients treated with true acupuncture exhibited significantly less pain, more functionality and an improved quality of life.

 

What about the rest of the body?

If you were to walk past a traditional Chinese acupuncture clinic, you would be able to see a long list of ailments, which the acupuncturists claim to be able to treat, from infertility to migraines to asthma. Traditional Chinese medicine is built on the basis of diagnosing and treating a pattern of disease rather than the disease itself. Treatment is therefore aimed at preventing the root cause of the problem, not the problem itself. It is based on restoring balance to the body.

The acupuncture points (over 300) are located along meridians (lines) which run from the tips of the limbs to the chest or head and, on the dorsal and ventral midline. The belief within traditional Chinese medicine is that a blockage within these lines causes illness, so unblocking them helps to restore balance and hence normal function.

Although this works through the release of anti-inflammatories, opioids and serotonin, is there actually any evidence about how these changes can be beneficial in disease? And, is this evidence objective enough to be considered useful enough to form a basis for treatment? Researching a number of articles, I decided to use examples that were based on quantitative findings – meaning did the frequency and duration of the condition change, based on statistical differences between treated and control (not treated) groups. This was also a good exercise to ensure my personal bias was not influencing what I was thinking.

There is quantitative evidence which supports the use of acupuncture in:

• Reducing migraine episodes and their duration¹²
• Assisting with IVF treatments¹³
• Improving lung function in people with chronic obstructive pulmonary disease¹⁴

Further information can be found here: https://www.evidencebasedacupuncture.org/acupuncture-scientific-evidence/#

The full mechanism of how acupuncture works for these conditions is still not fully understood however, it is based on the ‘somato-autonomic reflex’¹⁵. In basic terms, the ‘somato-’ part refers to the sensation on the skin (pain, cold, vibration, puncture etc.), and the ‘-autonomic’ part refers to processes which go on in the body that we do not have direct control over (such as heart rate, blood pressure, and intestinal movement).

The mechanism is therefore based on the thinking that the sensation from an acupuncture needle inserted into a specific acupuncture point activates a unique part of the brain and, this can have a special autonomic response. The effects of particular acupoints have mainly been documented based on trial and error, however further scientific evidence is needed.

So, how can acupuncture help your animal?

Firstly, the obvious way acupuncture can help is to reduce musculoskeletal pain. It has been shown to improve ¹⁶ and decrease back pain¹⁷ in horses. A decrease in lower back pain can also be useful for breeding stallions, as excessive breeding with mares or usage of dummy mounts can result in lower back pain that can result in both decreased performance and a lower fertility rate. Acupuncture also decreases pain and neurological signs, resulting in an improved quality of life, in dogs ¹.

Secondly, acupuncture can help to improve performance or, as a maintenance procedure to help keep ahorse comfortable. Limiting pain when it is known that an animal is susceptible to a certain condition can help to decrease its consequential effects.

Thirdly, electroacupuncture can be beneficial in nerve regeneration ¹⁹, treating conditions such as radial nerve paralysis. Electroacupuncture can also be used to laryngeal hemiplegia treat (roarers) ²⁰ and headshaking²¹.

Finally, an integrative, traditional Chinese medicine approach can be followed to try to diagnose the underlying pattern of disease. Although a scientific evidence base is preferred, this article has hopefully shown that acupuncture can have a number of benefits which are not fully understood. Acupuncture is just one branch of traditional Chinese medicine, and may be combined with its other branches, including herbal medicine and massage. Veterinary acupuncturists are always happy to discuss whether they think that acupuncture could help with a certain condition.

References

1. Pintov, S., Lahat, E., Alstein, M., Vogel, Z. and Barg, J., 1997. Acupuncture and the opioid system: Implications in management of migraine. Pediatric Neurology, 17(2), pp.129-133
2. Biçer, M., Bozkurt, D., Çabalar, M., Işıksaçan, N., Gedikbaşı, A., Bajrami, A. and Aktaş, I., 2017. The clinical efficiency of acupuncture in preventing migraine attacks and its effect on serotonin levels. Türkiye Fiziksel Tıp ve Rehabilitasyon Dergisi, 63(1), pp.59-65.
3. Shi, G.-X., Tu, J.-F., Wang, T.-Q., Yang, J.-W., Wang, L.-Q., Lin, L.-L., Wang, Y., Li, Y.-T. and Liu, C.-Z. (2020). Effect of Electro-Acupuncture (EA) and Manual Acupuncture (MA) on Markers of Inflammation in Knee Osteoarthritis. Journal of Pain Research, Volume 13, pp.2171–2179.
4. Zhang, W., Jeong, D., Lee, Y. and Lee, M., 2004. Measurement of Subcutaneous Impedance by Four-Electrode Method at Acupoints Located with Single-Power Alternative Current. The American Journal of Chinese Medicine, 32(05), pp.779-788.
5. Pearson, S., Colbert, A., McNames, J., Baumgartner, M. and Hammerschlag, R., 2007. Electrical Skin Impedance at Acupuncture Points. The Journal of Alternative and Complementary Medicine, 13(4), pp.409-418.
6. Li, F., He, T., Xu, Q., Lin, L., Li, H., Liu, Y., Shi, G. and Liu, C., 2015. What is the Acupoint? A preliminary review of Acupoints. Pain Medicine, 16, pp.1905-1915.
7. Langevin, H., Churchill, D., Wu, J., Badger, G., Yandow, J., Fox, J. and Krag, M., 2002. Evidence of Connective Tissue Involvement in Acupuncture. The FASEB Journal, 16(8), pp.872-874.
8. Langevin, H., Churchill, D. and Cipolla, M., 2001. Mechanical signaling through connective tissue: a mechanism for the therapeutic effect of acupuncture. The FASEB Journal, 15(12), pp.2275-2282.
9. Yu, Z., Wang, Y., Li, Y., Liao, C., Dai, J., Luo, Y., Hu, Y., Tao, S., Tang, J., Chen, G. and Wu, P., 2020. Effect of Moxibustion on the Serum Levels of MMP-1, MMP-3, and VEGF in Patients with Rheumatoid Arthritis. Evidence-Based Complementary and Alternative Medicine, 2020, pp.1-9.
10. Zhong, Y., Cheng, B., Zhang, L., Lu, W., Shang, Y. and Zhou, H., 2020. Effect of Moxibustion on Inflammatory Cytokines in Animals with Rheumatoid Arthritis: A Systematic Review and Meta-Analysis. Evidence-Based Complementary and Alternative Medicine, 2020, pp.1-12.
11. Lenoir, D., De Pauw, R., Van Oosterwijck, S., Cagnie, B. and Meeus, M. (2020). Acupuncture Versus Sham-acupuncture. The Clinical Journal of Pain, 36, pp. 533–549.
12. Shen, F., Xu, J., Zhan, Y., Fu, Q. and Pei, J., 2019. Acupuncture for migraine: A systematic review and meta-analysis. World Journal of Acupuncture – Moxibustion, 29(1), pp.7-14.
13. Smith, C., Armour, M., Shewamene, Z., Tan, H., Norman, R. and Johnson, N., 2019. Acupuncture performed around the time of embryo transfer: a systematic review and meta-analysis. Reproductive BioMedicine Online, 38(3), pp.364-379.
14. Wang, J., Li, J., Yu, X. and Xie, Y., 2018. Acupuncture Therapy for Functional Effects and Quality of Life in COPD Patients: A Systematic Review and Meta-Analysis. BioMed Research International, 2018, pp.1-19.
15. Andersson, S. and Lundeberg, T., 1995. Acupuncture — from empiricism to science: Functional background to acupuncture effects in pain and disease Pain and disease. Medical Hypotheses, 45(3), pp.271-281.
16. Dunkel, B., Pfau, T., Fiske-Jackson, A., Veres-Nyeki, K., Fairhurst, H., Jackson, K., Chang, Y. and Bolt, D., 2017. A pilot study of the effects of acupuncture treatment on objective and subjective gait parameters in horses. Veterinary Anaesthesia and Analgesia, 44(1), pp.154-162.
17. Xie, H., Colahan, P. and Ott, E., 2005. Evaluation of electroacupuncture treatment of horses with signs of chronic thoracolumbar pain. Journal of the American Veterinary Medical Association, 227(2), pp.281-286.
18. Silva, N., Luna, S., Joaquim, J., Coutinho, H. and Possebon, F., 2020. Effect of acupuncture on pain and quality of life in canine neurological and musculoskeletal diseases. Canadian Veterinary Journal, 58, pp.941-951.
19. von Schweinitz, D., 2013. Electroacupuncture for nerve injury in the horse. Equine Veterinary Education, 26(1), pp.24-26.
20. Kim, M. and Xie, H., 2009. Use of electroacupuncture to treat laryngeal hemiplegia in horses. Veterinary Record, 165(20), pp.602-603.
21. Devereux, S., 2017. Electroacupuncture as an additional treatment for headshaking in six horses. Equine Veterinary Education, 31(3), pp.137-146.