veterinary medicine
Low-level laser therapy has been used clinically to treat musculoskeletal pain; however, there is limited evidence available to support its use. The current Cochrance review fails to be positive: there are insufficient data to draw firm conclusions on the clinical effect of LLLT for low‐back pain. So, perhaps studies on animals generate clearer answers?
The objective of this study was to evaluate the clinical effectiveness of low-level laser therapy and chiropractic care in treating thoracolumbar pain in competitive western performance horses. The subjects included 61 Quarter Horses actively involved in national western performance competitions judged to have back pain. A randomized, clinical trial was conducted by assigning affected horses to either:
- laser therapy,
- chiropractic,
- or combined laser and chiropractic treatment groups.
Low-level laser therapy was applied topically to local sites of back pain. The laser probe contained four 810-nm laser diodes spaced 15-mm apart in a square array that produced a total optical output power of 3 watts. Chiropractic treatment was applied to areas of pain and stiffness within the thoracolumbar and sacral regions. A single application of a high velocity, low-amplitude (HVLA) manual thrust was applied to affected vertebral segments using a reinforced hypothenar contact and a body-centered, body-drop technique. The HVLA thrusts were directed dorsolateral to ventromedial (at a 45° angle to the horizontal plane) with a segmental contact near the spinous process with the goal of increasing extension and lateral bending within the adjacent vertebral segments. If horses did not tolerate the applied chiropractic treatment, then truncal stretching, spinal mobilization, and the use of a springloaded, mechanical-force instrument were used as more conservative forms of manual therapy in these acute back pain patients.
Outcome parameters included a visual analog scale (VAS) of perceived back pain and dysfunction and detailed spinal examinations evaluating pain, muscle tone, and stiffness. Mechanical nociceptive thresholds were measured along the dorsal trunk and values were compared before and after treatment. Repeated measures with post-hoc analysis were used to assess treatment group differences.
Low-level laser therapy, as applied in this study, produced significant reductions in back pain, epaxial muscle hypertonicity, and trunk stiffness. Combined laser therapy and chiropractic care produced similar reductions, with additional significant decreases in the severity of epaxial muscle hypertonicity and trunk stiffness. Chiropractic treatment by itself did not produce any significant changes in back pain, muscle hypertonicity, or trunk stiffness; however, there were improvements in trunk and pelvic flexion reflexes.
The authors concluded that the combination of laser therapy and chiropractic care seemed to provide additive effects in treating back pain and trunk stiffness that were not present with chiropractic treatment alone. The results of this study support the concept that a multimodal approach of laser therapy and chiropractic care is beneficial in treating back pain in horses involved in active competition.
Let me play the devil’s advocate and offer a different conclusion:
These results show that horses are not that different from humans when it comes to responding to treatments. One placebo has a small effect; two placebos generate a little more effects.
Apparently, Hahnemann gave a lecture on the subject of veterinary homeopathy in the mid-1810s. Ever since, homeopathy has been used for treating animals. Von Boennighausen was one of the first influential proponents of veterinary homeopathy. However, veterinary medical schools tended to reject homoeopathy, and the number of veterinary homeopaths remained small. In the 1920ies, veterinary homoeopathy was revived in Germany. Members of the “Studiengemeinschaft für tierärztliche Homöopathie” (Study Group for Veterinary Homoeopathy) which was founded in 1936 started to investigate this approach systematically.
Today, veterinary homeopathy is still popular in some countries. Prince Charles has become a prominent advocate who claims to treat his own life stock with homeopathy. In many countries, veterinary homeopaths have their own professional organisations. Elsewhere, however, veterinarians are banned from practicing homeopathy. In the UK, only veterinarians are allowed to use homeopathy on animals (but anyone regardless of background can use it on human patients) and there is a British Academy of Veterinary Homeopathy. In the US, homeopathic vets are organised in the Academy of Veterinary Homeopathy.
If this sounds promising, we should not forget that, as discussed so often on this blog, homeopathy lacks plausibility the evidence for veterinary homeopathy fails to be positive (see for instance here). But, hold on, there is a new study, perhaps it will change everything?
This ‘study‘ was aimed at providing an initial insight into the existing prerequisites on dairy farms for the use of homeopathy (i.e. the consideration of homeopathic principles) and on homeopathic treatment procedures (including anamnesis, clinical examination, diagnosis, selection of a remedy, follow-up checks, and documentation) on 64 dairy farms in France, Germany and Spain.
The use of homeopathy was assessed via a standardised questionnaire during face-to-face interviews. The results revealed that homeopathic treatment procedures were applied very heterogeneously and differed considerably between farms and countries. Farmers also use human products without veterinary prescription as well as other prohibited substances.
The authors of this ‘study’ concluded that the subjective treatment approach using the farmers’ own criteria, together with their neglecting to check the outcome of the treatment and the lack of appropriate documentation is presumed to substantially reduce the potential for a successful recovery of the animals from diseases. There is, thus, a need to verify the effectiveness of homeopathic treatments in farm practices based on a lege artis treatment procedure and homeopathic principles which can be achieved by the regular monitoring of treatment outcomes and the prevailing rate of the disease at herd level. Furthermore, there is a potential risk to food safety due to the use of non-veterinary drugs without veterinary prescription and the use of other prohibited substances.
So did this ‘study’ change the evidence on veterinary homeopathy?
Sadly not!
This ‘study’ is hardly worth the paper it is printed on.
Who conceives such nonsense?
And who finances such an investigation?
The answer to the latter question is one of the few provided by the authors: This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under Grant Agreement No 311824 (IMPRO).
Time for a constructive suggestion! Could the European Union’s Seventh Framework Programme with their next research project in veterinary homeopathy please evaluate the question why farmers in the EU are allowed to use disproven therapies on defenceless animals?
So-called alternative medicine (SCAM) for animals is popular. A recent survey suggested that 76% of US dog and cat owners use some form of SCAM. Another survey showed that about one quarter of all US veterinary medical schools run educational programs in SCAM. Amazon currently offers more that 4000 books on the subject.
The range of SCAMs advocated for use in animals is huge and similar to that promoted for use in humans; the most commonly employed practices seem to include acupuncture, chiropractic, energy healing, homeopathy (as discussed in the previous post) and dietary supplements. In this article, I will briefly discuss the remaining 4 categories.
ACUPUNCTURE
Acupuncture is the insertion of needles at acupuncture points on the skin for therapeutic purposes. Many acupuncturists claim that, because it is over 2 000 years old, acupuncture has ‘stood the test of time’ and its long history proves acupuncture’s efficacy and safety. However, a long history of usage proves very little and might even just demonstrate that acupuncture is based on the pre-scientific myths that dominated our ancient past.
There are many different forms of acupuncture. Acupuncture points can allegedly be stimulated not just by inserting needles (the most common way) but also with heat, electrical currents, ultrasound, pressure, bee-stings, injections, light, colour, etc. Then there is body acupuncture, ear acupuncture and even tongue acupuncture. Traditional Chinese acupuncture is based on the Taoist philosophy of the balance between two life-forces, ‘yin and yang’. In contrast, medical acupuncturists tend to cite neurophysiological theories as to how acupuncture might work; even though some of these may appear plausible, they nevertheless are mere theories and constitute no proof for acupuncture’s validity.
The therapeutic claims made for acupuncture are legion. According to the traditional view, acupuncture is useful for virtually every condition. According to ‘Western’ acupuncturists, acupuncture is effective mostly for chronic pain. Acupuncture has, for instance, been used to improve mobility in dogs with musculoskeletal pain, to relieve pain associated with cervical neurological disease in dogs, for respiratory resuscitation of new-born kittens, and for treatment of certain immune-mediated disorders in small animals.
While the use of acupuncture seems to gain popularity, the evidence fails to support this. Our systematic review of acupuncture (to the best of my knowledge the only one on the subject) in animals included 14 randomized controlled trials and 17 non-randomized controlled studies. The methodologic quality of these trials was variable but, on average, it was low. For cutaneous pain and diarrhoea, encouraging evidence emerged that might warrant further investigation. Single studies reported some positive inter-group differences for spinal cord injury, Cushing’s syndrome, lung function, hepatitis, and rumen acidosis. However, these trials require independent replication. We concluded that, overall, there is no compelling evidence to recommend or reject acupuncture for any condition in domestic animals. Some encouraging data do exist that warrant further investigation in independent rigorous trials.
Serious complications of acupuncture are on record and have repeatedly been discussed on this blog: acupuncture needles can, for instance, injure vital organs like the lungs or the heart, and they can introduce infections into the body, e. g. hepatitis. About 100 human fatalities after acupuncture have been reported in the medical literature – a figure which, due to lack of a monitoring system, may disclose just the tip of an iceberg. Information on adverse effects of acupuncture in animals is currently not available.
Given that there is no good evidence that acupuncture works in animals, the risk/benefit balance of acupuncture cannot be positive.
CHIROPRACTIC
Chiropractic was created by D D Palmer (1845-1913), an American magnetic healer who, in 1895, manipulated the neck of a deaf janitor, allegedly curing his deafness. Chiropractic was initially promoted as a cure-all by Palmer who claimed that 95% of diseases were due to subluxations of spinal joints. Subluxations became the cornerstone of chiropractic ‘philosophy’, and chiropractors who adhere to Palmer’s gospel diagnose subluxation in nearly 100% of the population – even in individuals who are completely disease and symptom-free. Yet subluxations, as understood by chiropractors, do not exist.
There is no good evidence that chiropractic spinal manipulation might be effective for animals. A review of the evidence for different forms of manual therapies for managing acute or chronic pain syndromes in horses concluded that further research is needed to assess the efficacy of specific manual therapy techniques and their contribution to multimodal protocols for managing specific somatic pain conditions in horses. For other animal species or other health conditions, the evidence is even less convincing.
In humans, spinal manipulation is associated with serious complications (regularly discussed in previous posts), usually caused by neck manipulation damaging the vertebral artery resulting in a stroke and even death. Several hundred such cases have been documented in the medical literature – but, as there is no system in place to monitor such events, the true figure is almost certainly much larger. To the best of my knowledge, similar events have not been reported in animals.
Since there is no good evidence that chiropractic spinal manipulations work in animals, the risk/benefit balance of chiropractic fails to be positive.
ENERGY HEALING
Energy healing is an umbrella term for a range of paranormal healing practices, e. g. Reiki, Therapeutic Touch, Johrei healing, faith healing. Their common denominator is the belief in an ‘energy’ that can be used for therapeutic purposes. Forms of energy healing have existed in many ancient cultures. The ‘New Age’ movement has brought about a revival of these ideas, and today ‘energy’ healing systems are amongst the most popular alternative therapies in many countries.
Energy healing relies on the esoteric belief in some form of ‘energy’ which refers to some life force such as chi in Traditional Chinese Medicine, or prana in Ayurvedic medicine. Some proponents employ terminology from quantum physics and other ‘cutting-edge’ science to give their treatments a scientific flair which, upon closer scrutiny, turns out to be little more than a veneer of pseudo-science.
Considering its implausibility, energy healing has attracted a surprisingly high level of research activity in the form of clinical trials on human patients. Generally speaking, the methodologically best trials of energy healing fail to demonstrate that it generates effects beyond placebo. There are few studies of energy healing in animals, and those that are available are frequently less than rigorous (see for instance here and here). Overall, there is no good evidence to suggest that ‘energy’ healing is effective in animals.
Even though energy healing is per se harmless, it can do untold damage, not least because it can lead to neglect of effective treatments and it undermines rationality in our societies. Its risk/benefit balance therefore fails to be positive.
DIETARY SUPPLEMENTS
Dietary supplements for veterinary use form a category of remedies that, in most countries, is a regulatory grey area. Supplements can contain all sorts of ingredients, from minerals and vitamins to plants and synthetic substances. Therefore, generalisations across all types of supplements are impossible. The therapeutic claims that are being made for supplements are numerous and often unsubstantiated. Although they are usually promoted as natural and safe, dietary supplements do not have necessarily either of these qualities. For example, in the following situations, supplements can be harmful:
- Combining one supplement with another supplement or with prescribed medicines
- Substituting supplements for prescription medicines
- Overdosing some supplements, such as vitamin A, vitamin D, or iron
Examples of currently most popular supplements for use in animals include chondroitin, glucosamine, probiotics, vitamins, minerals, lutein, L-carnitine, taurine, amino acids, enzymes, St John’s wort, evening primrose oil, garlic and many other herbal remedies. For many supplements taken orally, the bioavailability might be low. There is a paucity of studies testing the efficacy of dietary supplements in animals. Three recent exceptions (all of which require independent replication) are:
- A trial showing that the dietary supplementation with Maca increased sperm production in stallions.
- A study demonstrating that curcumin supplementation appeared to reduce arthritis pain in dogs.
- An investigation suggesting that royal jelly supplementation can improve the egg quality of hens.
Dietary supplements are promoted as being free of direct risks. On closer inspection, this notion turns out to be little more than an advertising slogan. As discussed repeatedly on this blog, some supplements contain toxic materials, contaminants or adulterants and thus have the potential to do harm. A report rightly concluded that many challenges stand in the way of determining whether or not animal dietary supplements are safe and at what dosage. Supplements considered safe in humans and other cross-species are not always safe in horses, dogs, and cats. An adverse event reporting system is badly needed. And finally, regulations dealing with animal dietary supplements are in disarray. Clear and precise regulations are needed to allow only safe dietary supplements on the market.
It is impossible to generalise about the risk/benefit balance of dietary supplements; however, caution is advisable.
CONCLUSION
SCAM for animals is an important subject, not least because of the current popularity of many treatments that fall under this umbrella. For most therapies, the evidence is woefully incomplete. This means that most SCAMs are unproven. Arguably, it is unethical to use unproven medicines in routine veterinary care.
PS
I was invited several months ago to write this article for VETERINARY RECORD. It was submitted to peer review and subsequently I withdrew my submission. The above post is a slightly revised version of the original (in which I used the term ‘alternative medicine’ rather than ‘SCAM’) which also included a section on homeopathy (see my previous post). The reason for the decision to withdraw this article was the following comment by the managing editor of VETERINARY RECORD: A good number of vets use these therapies and a more balanced view that still sets out their efficacy (or otherwise) would be more useful for the readership.
Ever since Samuel Hahnemann, the German physician who invented homeopathy, gave a lecture on the subject in the mid-1810s, homeopathy has been used for treating animals. Initially, veterinary medical schools tended to reject homoeopathy as implausible, and the number of veterinary homeopaths remained small. In the 1920ies, however, veterinary homoeopathy was revived in Germany, and in 1936, members of the “Studiengemeinschaft für tierärztliche Homöopathie” (Study Group for Veterinary Homoeopathy) started to investigate homeopathy systematically.
Today, veterinary homeopathy is popular not least because of the general boom in so-called alternative medicine (SCAM). Prince Charles is just one of many prominent advocates who claims to treat animals with homeopathy. In many countries, veterinary homeopaths have their own professional organisations, while elsewhere veterinarians are banned from practicing homeopathy. In the UK, only veterinarians are currently allowed to use homeopathy on animals (but ironically, anyone regardless of background can use it on human patients).
Considering the implausibility of its assumptions, it seems unlikely that homeopathic remedies can be anything other than placebos. Yet homeopaths and their followers regularly produce clinical trials that seem to suggest efficacy. Today, there are about 500 controlled clinical trials of homeopathy (mostly on humans), and it is no surprise that, purely by chance, some of them show positive results. To avoid being misled by random findings, cherry-picking, or flawed science, we ought to critically evaluate the totality of the available evidence. In other words, we should rely not on single studies but on systematic reviews of all reliable trials.
A 2015 systematic review by ardent homeopaths tested the hypothesis that the outcome of veterinary homeopathic treatments is distinguishable from placebos. A total of 15 trials could be included, but only two comprised reliable evidence without overt vested interest. The authors concluded that there is “very limited evidence that clinical intervention in animals using homeopathic medicines is distinguishable from corresponding intervention using placebos.”
A more recent systematic review compared the efficacy of homeopathy to that of antibiotics in cattle, pigs and poultry. A total number of 52 trials were included of which 28 were in favour of homeopathy and 22 showed no effect. No study had been independently replicated. The authors concluded that “the use of homeopathy cannot claim to have sufficient prognostic validity where efficacy is concerned.”
Discussing this somewhat unclear and contradictory findings of trials of homeopathy for animals, Lee et al concluded that “…it is overwhelmingly likely that small effects observed in the RCTs and systematic reviews are the result of residual bias in the trials.” To this, I might add that ‘publication bias’, i. e. the phenomenon that negative trials often remain unpublished, might be the reason why systematic reviews of homeopathy are never entirely negative.
In recent years, several scientific bodies have assessed the evidence on homeopathy and published statements about it. Here are the key passages from some of these ‘official verdicts’:
“The principles of homeopathy contradict known chemical, physical and biological laws and persuasive scientific trials proving its effectiveness are not available”
Russian Academy of Sciences, Russia
“Homeopathy should not be used to treat health conditions that are chronic, serious, or could become serious. People who choose homeopathy may put their health at risk if they reject or delay treatments for which there is good evidence for safety and effectiveness.”
National Health and Medical Research Council, Australia
“These products are not supported by scientific evidence.”
Health Canada, Canada
“Homeopathic remedies don’t meet the criteria of evidence-based medicine.”
Hungarian Academy of Sciences, Hungary
“The incorporation of anthroposophical and homeopathic products in the Swedish directive on medicinal products would run counter to several of the fundamental principles regarding medicinal products and evidence-based medicine.”
Swedish Academy of Sciences, Sweden
“There is little evidence to support homeopathy as an effective treatment for any specific condition”
National Centre for Complementary and Integrative Health, USA
“There is no good-quality evidence that homeopathy is effective as a treatment for any health condition”
National Health Service, UK
“Homeopathic remedies perform no better than placebos, and the principles on which homeopathy is based are “scientifically implausible””
House of Commons Science and Technology Committee, UK
“Homeopathy has not definitively proven its efficacy in any specific indication or clinical situation.”
Ministry of Health, Spain
“… homeopathy should be treated as one of the unscientific methods of the so called ‘alternative medicine’, which proposes worthless products without scientifically proven efficacy.”
National Medical Council, Poland
“… there is no valid empirical proof of the efficacy of homeopathy beyond the placebo effect.”
Federaal Kenniscentrum voor de Gezondheidszorg, Belgium
As they are usually far too dilute to contain anything, homeopathic remedies are generally harmless, provided they are produced according to good manufacturing practice (which is not always the case). Unfortunately, however, this harmlessness does not necessarily apply to homeopathy in general. When employed to replace an effective therapy, even the most innocent but ineffective treatment can become life-threatening. Since homeopaths recommend their remedies for even the most serious conditions, this is by no means a theoretical consideration. I have therefore often stated that HOMEOPATHICS MIGHT BE HARMLESS, BUT HOMEOPATHS CERTAINLY ARE NOT.
It follows that an independent risk/benefit analysis of homeopathy fails to arrive at a positive conclusion. In other words, homeopathy has not been shown to generate more good than harm. In turn, this means that homeopathy has no place in veterinary (or human) evidence-based medicine.
