Acupuncture: The science behind the practice (Proceedings)

Acupuncture is still regarded with skepticism by many veterinarians, or viewed as adjunct therapy rather than a primary therapy. It is especially useful for chronic conditions, and for some where there is no good solution in Western Medicine.

Evidence for acupuncture points

First, is there such a thing as an acupuncture point? Some studies have shown that merely placing a needle in the skin can cause some of the effects of acupuncture, though to a lesser extent. Vasodilation and subsequent feelings of heat are present when any skin is punctured with an acupuncture needle. Anyone who has observed reactions from a splinter will not be surprised at this research.

There is no one single anatomical structure that can be identified as an acupuncture point. However, there are a number of things most points have in common. Two of the most common anatomical structures are:

Free nerve endings as part of a neurovascular bundle, wrapped in connective tissue sheath.

Holes: where cutaneous nerves emerge from deep fascia, or from bony foramina, or penetration of deep fascia by bundles of nerves and vessels

One of the more compelling points of evidence is the decreased electrical resistance of the skin over acupuncture points (in 50% of points in people, 79% in dogs in one study), using a "point finder", or ohmmeter with a sensitivity of millivolts and microamps. Some studies have found no difference. Discrepancies can arise from: the sensitivity (or lack thereof) of the point finder, the measuring technique used (pressing too hard/not hard enough, and too little differentiation of areas), the physiologic state of the animal (damp skin lowers skin resistance so a sweaty horse can appear to have points all over the body), and the environment (humid vs dry).

Injection of local anesthetic into acupoints before electroacupuncture abolishes the analgesic effect.

In about 1% of sport horses, there is a pilomotor reaction along the bladder meridian during acupuncture: it starts a few minutes after needle insertion, at maximum 10 minutes after needle insertion. Hair is raised in small clumps at acupuncture points.

Analgesic effects have been attributed to a placebo effect in humans, or to wanting to believe their dog is better. There are 5 exam rooms in my practice, and I primarily use one. Often, if owners try to take their dog to another room, the dog will try to pull them into my primary exam room. More than once, I have had aggressive or painful dogs and cats that begin their first treatment by trying to bite and claw me, and end up with tail-wagging sessions. The most dramatic was Guido, aptly-named German shepherd cross who tried to attack on the first visit, and on the second visit gazed into my eyes while wagging his tail, then turned around and sat on my feet.

Neurophysiologic basis for acupuncture points

Segmental analgesia: gate theory

Endogenous opioids are found in the CSF and brain and spinal cord tissue after acupuncture: met- and leu-enkephalin in brain, beta endorphin in brain and CSF, dynorphin and enkephalins in spinal cord increase with acupuncture.

Serotonin is also released with acupuncture. If you block serotonin, endorphins increase and vice versa. With acupuncture, if you block one or the other, there is a moderate decrease in analgesia. Blocking both results in a profound decrease in acupuncture analgesia.

Analgesia from acupuncture is blocked by naloxone. Anticholinergics decrease acupuncture analgesia. Parasympathomimetics increase it.

Needling causes vasodilation and measurable increase in skin temperature.

Specific research

Beware of Chinese studies published in 1960's and 1970's (political situation=tell politicians what they want to hear).

Analgesia:

• Humans: twice as effective as piroxicam.

• Chronic pain: 73% still asymptomatic after 6 years

• Dogs: 70% of dogs with DJD showed >50% improvement in mobility and ambulation

• IV disc disease: A Swedish study showed that as long as deep pain was still present, immediate results of acupuncture were the same as surgery. There were more relapses with acupuncture, presumably because no discs were fenestrated.

• Another study showed more rapid recovery from surgery for IVDD when acupuncture was included than when only surgery was performed.

• Horses: chronic back pain and distal tarsal pain improves with acupuncture (multiple articles)

• One case study of a dog that was tetraparetic from a cervical disc recovered use of all limbs with acupuncture and herbs alone.

• Eyes: Acupuncture reduced intra-ocular pressure

Cardiovascular collapse:

In dogs, stimulation of GV-26 (on the midline just under the nasal pad) increases heart rate, stroke volume, cardiac output, and pulse pressure, comparable to injections of epinephrine. It also increases mean arterial pressure and decreases total peripheral resistance. This effect can be blocked by propanolol. Rescusitaton from apnea via thiopental in 88% using GV26 vs 40% when stimulating a non-acupuncture point. No effect was seen in ponies under halothane anesthesia. (Too much anesthetic? Species related?)

• Also useful for hypertension, tachyarrhythmias, pvcs, bradyarrhythmias. Humans: hypertrophic cardiomyopathy: HT6, PC6

• In reproduction, studies in sows, sheep, and women: Alters levels of LH, FSH, estradiol, progesterone

• (1-2 hrs post acupuncture for LH in sows and sheep, increases plasma progesterone in 4-6 hrs for sows.)

Immune system:

• (too much leads to adaptation, decreased effect)

• Enhances RBC and WBC return to normal in many conditions, including radiation sickness

• postop: enhances WBC and lymphocyte counts, neutrophil phagocytosis, bactericidal activity

• enhances cellular immunity, increases lymphocyte proliferation/count, increased NK cell activity, increased suppressor/cytotoxic T cells.

• Mice" increased IgA in small intestine for Vibrio cholerae.

• Dogs: beta and gamma globulins increased with GI helminthiasis. Increased antibody formation in wounded horses.

GI tract:

Megaesophagus: dogs improved

Post operative ileus in horses was relieved by acupuncture. (It is useful for early megacolon in cats, in my practice.) GV1 reduced contractions of the anterior colon in dogs in one study, but, interestingly, a number of LI points did not. In my practice, mild rectal prolapse has been successfully treated with gentle replacement and acupuncture alone. Severe or chronic conditions do not respond as well.

Acupuncture has helped nausea and vomiting from chemotherapy and from morning sickness in women, and prevented xylazine-induced vomiting in dogs.

Piglet diarrhea from e coli and corona virus responded the same as antibiotics in one study.

Lamb dysentery unresponsive to medication: increased intestinal microciruculation in 15 minutes and decreasedhyperperistalsis and borborygmus in 15 to 30 minutes with acupuncture.

• Urinary bladder: Helps dysuria, urinary urgency, irritable bladder, bladder function. In my practice, an Akita with degenerative myelopathy, unable to walk, had a urinary tract infection that was resistant to all drugs except Amikacin. The dog was uncomfortable and had strong-smelling hematuria. E coli had been isolated at >100,000 CFU. Acupuncture made her comfortable immediately and a Chinese herbal formula (Akebia Moist Heat) stopped the hematuria and reduced the bacterial count to <10,000 CFU.

• Renal failure: Renal failure induced by administering propylene glycol showed improvement in dogs treated with acupuncture compared to the controls with no treatment. In my practice, I treated a cat with a BUN of 254 who refused to eat any renal diet, was impossible to give sub-cutaneous fluids to, and who had stopped eating or drinking. She allowed only 5 needles to be placed. After acupuncture, she started eating and drinking, and continued for one month, at which time she stopped again. The process was repeated 5 times with the same results. At the 6th repetition, she did not respond and was euthanized.

References

Allen Schoen, DVM, Veterinary Acupuncture, Ancient Art to Modern Medicine, St. Louis, MO, 1994, Mosby. The basic reference for veterinary acupuncture

Electroacupuncture analgesia in dogs: is there a difference between uni- and bi-lateral stimulation?

Vet Anaesth Analg. January 2008;35(1):52-61.Renata N Cassu1, Stelio P L Luna, Rosana M O Clark, Sérgio N KronkaDifferent effects of electroacupuncture on esophageal motility and serum hormones in cats with esophagitis

Dis Esophagus. 2008;21(2):170-5.X Shuai1, P Xie, J Liu, Y Xiang, J Li, Y LanRole of medullary GABA, opioids, and nociceptin in prolonged inhibition of cardiovascular sympathoexcitatory reflexes during electroacupuncture in cats

Am J Physiol Heart Circ Physiol. December 2007;293(6):H3627-35.Stephanie C Tjen-A-Looi1, Peng Li, John C LonghurstEffects of electroacupuncture on intraocular pressure and hemodynamic parameters in isoflurane anesthetized dogs

J Vet Med Sci. November 2007;69(11):1163-5.Min-Su Kim1, Jong-Hyun Yoo, Kang-moon Seo, Seong Mok JeongEvaluation of electroacupuncture treatment for thoracolumbar intervertebral disk disease in dogs

J Am Vet Med Assoc. September 2007;231(6):913-8.Ayne Murata Hayashi1, Julia Maria Matera, Ana Carolina Brandão de Campos Fonseca PintoElectro-acupuncture and Chinese herbs for treatment of cervical intervertebral disk disease in a dog

J Vet Sci. March 2007;8(1):95-8.Ayne Murata Hayashi1, Julia Maria Matera, Tatiana Soares da Silva, Ana Carolina Brandao de Campos Fonseca Pinto, Silvia Renata Gaido CortopassiThe effect of oculo-acupuncture on recovery from ethylene glycol-induced acute renal injury in dogs

Am J Chin Med. 2007;35(2):241-50.Jianzhu Liu1, Kun-Ho Song, Myung-Jo You, Dong-Soo Son, Sung-Whan Cho, Duck-Hwan KimAnti-emetic effect of oculo-acupuncture on dogs with xylazine induced vomiting

Am J Chin Med. 2007;35(3):447-53.Jianzhu Liu1, Yoo-Teak Lee, Sang-Eun Lee, Jung-Yeon Lee, Duck-Hwan Kim

Effect of traditional acupuncture on proximal colonic motility in conscious dogs

J Vet Med Sci. June 2006;68(6):603-7.Hee-Young Kim1, Dae-Hyun Hahm, Kwang-Ho Pyun, Hye-Jung Lee, Tchi-chou Nam, Insop Shim