Acupuncture refers to a method of inserting thin, sterile, solid needles into specific sites on the body. Its myriad applications include the relief of pain and the treatment of organ dysfunction, immune disorders, and many other maladies. Although most think of fine needles when they hear the term, acupuncture actually incorporates an array of interventions that may be intended to augment the needle's effects, or even obviate needling altogether. Such interventions include electrical stimulation (ie, electroacupuncture); moxibustion, in which a smoldering herb is placed on tissue or on a needle embedded in the tissue; low level laser stimulation (laser-puncture); pressing techniques (acupressure); and injection of vitamins, saline, or other solutions into sites (aquapuncture).
It is often asserted that acupuncture, associated with “traditional Chinese medicine” (TCM), is a more-or-less direct descendent of metaphorical underpinnings of medicine that arose thousands of years ago in China. In fact, there is little association between the current practice of acupuncture and the historical practice of Chinese medicine. The ancient Chinese acupuncturists, like ancient physicians of all cultures, did not correctly outline the inner workings of the body. Some of these mistaken impressions about organ functions, perhaps stemming from the agrarian mindset suffusing Chinese culture at the time, became embedded in Chinese medical terminology and persist to this day. Metaphors such as “wind invasion” and “spleen damp heat” continue to describe disease processes in modern TCM.
While the roots of Chinese medicine can be traced as far back as the Han dynasty (206 BCE to 220 CE) or earlier, the concept of a “traditional Chinese medicine” represents a relatively recent invention. TCM was updated and compiled by order of Chairman Mao Tse Tung; the goal was to offer a revised and simplified compilation of Chinese medical theories that would aid in addressing the public health needs of an ailing and massive population in China, as well as to promote practices that were quintessentially Chinese as a matter of national pride. Subsequently, TCM was marketed to Western doctors. Cultural mixing of western practices with TCM and metaphysics converted acupuncture into “energy medicine.”
Some Chinese medicine-based practitioners may rely heavily on traditional methods of assessing patients, ie, tongue diagnosis and pulse diagnosis. The application of acupuncture to particular conditions based on the appearance of the tongue or the quality of the pulse have, as yet, little scientific underpinning. A good body of research exists to show that neither technique is reliable even for humans, whom these techniques primarily target. Many other variations of acupuncture philosophy and application exist. For example, the term “medical acupuncture” entered the veterinary vernacular in 1998, addressing the preferences of some veterinarians for an approach to acupuncture education and practice that rested on a rational and scientific foundation.
Mechanisms of Action
Many acupuncture practitioners believe that acupuncture works by moving invisible energies through unseen pathways (meridians or channels). The association of acupuncture with energy appears to stem from a mistranslation of the Chinese word “qi” into energy in the 1930s by the French author Georges Soulié de Morant. Healing “energies” have been postulated to be an important part of medicine for millennia; the Chinese concepts of “qi” were fundamentally no different than the concepts of “vital energies” typical of many other contemporaneous cultures. Such metaphysical explanations are unsatisfying for scientific practitioners; thus, other mechanisms of action have been postulated.
One theoretical mechanism of action suggests that acupuncture works through neuromodulation (the influencing of nerve impulses throughout the peripheral, central, and autonomic nervous systems). According to this theory, neuromodulation impels the body and mind toward a system-wide, restorative state of homeostasis. Research findings from physiologic studies show that acupuncture needles, or other devices, affect afferent nerve fibers in the skin, subcutaneous tissue, fascia, muscle, tendons, vascular walls, or periosteum, purportedly eliciting local or peripheral reflexes that have beneficial effects on the body.
Several explanations exist for how acupuncture reduces pain. Some assert that acupuncture interrupts nociceptive transmission at the level of the spinal cord, producing spinal segmental analgesia, or that acupuncture alters the processing and perception of pain centrally. Others have suggested that any pain-relieving effects may be more simply attributed to placebo effects, distraction, a diffuse noxious stimulus, or psychological alteration of the perception of pain. As yet there is no consensus on acupuncture's effects for the treatment of pain, but mounting evidence on the mechanisms and clinical benefits of acupuncture is gradually substantiating a scientific basis for clinically relevant pain treatment, whether of inflammatory, musculoskeletal, neuropathic, neoplastic, or visceral origin.
Various neurotransmitter and neuroendocrine responses have been associated with acupuncture. Specific parameters important for optimal effects in acupuncture are emerging as research defines how treatment design impacts clinical outcomes. For example, targeting specific dermatomes corresponding to local pathology rather than remote sites leads to greater improvements in pain control, physical activity, and sleep quality. Frequency and duration of stimulus also influence the analgesic response.
Rigorous research supporting the integration of acupuncture in the treatment of a wide array of conditions in veterinary medicine is lacking. Nevertheless, acupuncture is used to treat acute and chronic pain in veterinary patients based on insights derived from human and experimental animal work. Studies on horses with back pain indicate benefits from acupuncture; however, these have not been confirmed by good scientific trials. Growing evidence supports electroacupuncture for neurologic dysfunction and pain in dogs. Other conditions that have been treated with acupuncture include muscle tension, tendinitis, GI motility disorders, circulatory or immune dysfunction, reproductive disorders, and certain cardiopulmonary disorders.
Studies in humans support the strong safety profile of acupuncture. Pregnancy is sometimes considered a contraindication due to concerns that acupuncture might alter circulating levels of reproductive hormones; additional concerns might arise if acupuncture were to somehow stimulate spinal cord segments that supply the uterus. However, serious adverse effects from acupuncture for women in late pregnancy with low back and pelvic pain have not been demonstrated in well-designed studies. Coagulopathies or immune compromise might represent contraindications if needling leads to excessive bleeding or local infection, respectively.
Acupuncture may be contraindicated if an animal cannot remain still enough to perform needling safely. High levels of anxiety, fear, or aggression could counteract health-promoting autonomic changes generated by acupuncture. In such cases, efforts to calm the animal may be warranted.
Some TCM-based acupuncture practitioners may claim that cancer is a contraindication for acupuncture, even though no evidence exists to support the claim. Those who believe that acupuncture works through unseen energies hold that treating any point along a meridian may promote cancer growth by impelling energy into the tumor. The belief that acupuncture will encourage cancer metastasis because it can augment circulation is similarly unfounded; however, there is no proof that acupuncture itself fights cancer.
Acupuncture provided by medically educated professionals such as veterinarians produces few adverse effects and is generally considered safe. The risks of invading a major organ or vessel with a needle are minimal as long as the practitioner possesses sufficient awareness of the patient's anatomy. Extreme negative reactions to a needle may indicate that it has entered a nerve; in those cases, the needle should be withdrawn. Handlers of horses have been injured when horses have kicked during acupuncture treatment. Needle ingestion by the patient appears to constitute the most frequent concern in animals, although there are no published reports of injury. Adverse reactions that have been reported in people include fainting, skin infections, and hepatitis; such reactions have not been reported in animals.
The medical literature contains cases in which acupuncture needle fragments or implants have migrated to the spinal cord, peritoneal cavity, heart, stomach, liver, breast, brain, bladder, kidney, and colon. In animals, anecdotal radiographic evidence has shown that the implants can migrate long distances, eg, from the hip to the thoracolumbar region or abdominal wall. Embedding ferromagnetic objects in tissue may compromise the quality of computerized scans such as CT and MRI, causing artifacts and obscuring diagnoses. Gold bead implantation (GBI), the process of permanently inserting small bits of metal into the body as a type of “permanent acupuncture,” resembles a Japanese technique in which acupuncturists insert acupuncture needles into tissue and cut them off at the surface, leaving an implant. So far, no studies of GBI justify incurring the risks of migration and obscuring imaging studies.
Additional adverse effects of implants include activation of mast cells, argyria, contact dermatitis, and gold-induced myelotoxicity.
The fundamental tenets of energy-based acupuncture remain unproven. No evidence indicates that invisible meridians or qi energies exist. Due to the limited number of clinical studies in acupuncture for veterinary patients and the current disagreement regarding the scientific basis of acupuncture, acupuncture is not yet recognized as a specialty by the AVMA.
Other controversies in veterinary acupuncture involve point placements based on the “feel” of energy channels in animals, wherein practitioners assert that they know where the points historically described for people should lie on animals based on psychic impressions. This strains credulity and can lead to bizarre ideations about acupuncture, such as the generation of cancer treatment protocols based on imagined emotional interactions between imagined points.
Last full review/revision July 2011 by Narda G. Robinson, DO, DVM, MS, FAAMA