The Science of Homeopathy?

Posted on April 13, 2011 by skeptvet

Promoters of alternative medicine, especially the more wacky fringe varieties, have a love/hate relationship with science. On the one hand, science often fails to support their theories or claims of clinical effect, so they are inclined to dismiss it. “Allopathic” or “Western” medicine is caricatured as a mere point of view with no right to claim it is more accurate in its understanding of the world than ancient folk traditions or the individual epiphanies of folks like Hahnemann and Palmer. Or it is described rather patronizingly as ok for acute, life-threatening illness but merely treatment of symptoms whereas [insert CAM of choice] treats the one true cause of all disease. At worst, CAM proponents accuse science and science-based medicine of actually being a major cause of illness, with the demonization of vaccines, obsession with “toxins,” and wailing about the “cancer industry.”

On the other hand, people aren’t stupid, and most consumers of medical products and services understand that scientific medicine has done more to improve the quality and length of life in a couple of centuries than all other approaches achieved in the rest of human history. So science as a branding and marketing tool is powerful, and CAM practitioners crave both the validation of scientific evidence and the aura of legitimacy it can provide.

This conflict can generate an Orwellian doublethink in which CAM advocates simultaneously deride and dismiss science as a method for seeking knowledge and also claim that it proves them right. Of course, consistency is not the hallmark of CAM in general, since it is really an ideological umbrella term to associate various unrelated and often incompatible approaches to healthcare. But the mental gymnastics necessary to both claim their methods are scientifically valid and dismiss the same scientific method because it does not support their claims are sometimes dazzling.

The most recent example that I have run across is the list of offerings for the Academy of Veterinary Homeopathy (AVH) 2011 annual conference. The AVH certifies veterinarians as homeopaths and serves as an advocacy group for veterinary homeopathy. (It is important to note here that homeopathy and the AVH are not recognized as a legitimate specialty by the American Board of Veterinary Specialties, and so any “board certification” in homeopathy is a meaningless marketing label, not an indicator of meaningful advanced training or high quality care).

The title of the conference is The Science of Homeopathy. Of course, homeopathy is more properly described as a pseudoscience, an unscientific idea promoted as if it were scientifically legitimate, but I’ll get to that in a bit. Clearly, the title is intended to create an impression of scientific validation, though an impression of truthiness would be more accurate.

Some of the offerings presented as if they were scientifically validated are blatant nonsense founded on theories as antithetical to science as it is possible to be. Others are cleverly disguised in language that appears scientific but is mere obfuscation and gibberish. And a couple manage to be very articulate and rational on the surface while concealing deeply antiscientific thinking. All, however, illustrate the paradoxical process of CAM advocates seeking the appearance of scientific legitimacy while operating within a fundamentally anti-science view of the world.

Patricia Jordan- “Vaccinosis and its cure by thuja by J. Compton Burnett Revisited”

J. Compton Burnett in his work Vaccinosis and its cure by thuja presented an important work describing the subdivision of sycosis from vaccinations.  The recognition of this consideration as a utility in the consulting room or at the patient’s side is critical as the number of vaccines has increased in quantity and frequency of administration. Research into the vaccine issues will update and confirm the information Burnett already knew in the 1800’s. This presentation will offer the audience further insight into vaccinosis, the use of thuja and to the prophecy of Burnett and what he understood of the Pasteur’s vaccine “sailing right down this rock towards shipwreck”. Cases of vaccinosis with use of thuja will be presented. Also, emerging public health problems due to use of veterinary vaccines will be explored.

This session refers to a work by a homeopath published in 1884 that discusses supposed deleterious chronic illness associated with vaccination, called “vaccinosis,” and the benefits of a particular homeopathic nostrum in preventing and treating it. Vaccinosis is, like “allopathic,” a buzzword for the alternative medical community that instantly signals an anti-scientific stance. While I’ve discussed the risks and benefits of vaccination in detail,  and vaccines can undoubtedly cause unwanted illnesses, the concept of vaccinosis is completely without any scientific legitimacy. It is a polemical term used by anti-vaccination activists to generate irrational fear, and it is not grounded in any actual research of evidence. Many anecdotes are presented to “prove” vaccinosis exists, but these are all mere anecdotes and the link between symptoms described and vaccines is always assumed, never demonstrated.

The original work was, not surprisingly, wrong on many counts as it was written well before any real scientific understanding of the immune system was developed. The reverence shown to it illustrates the reliance of homeopathy on tradition and historical “visionaries” and the inability of practitioners to accept the advances in medical knowledge that have occurred since Hahnemann. Since homeopathy is fundamentally a vitalist belief system, not a scientific approach to healthcare, it is a classic example of the all-too common faith-based approach to medicine, which will seize on any scientific evidence that appears to support its ideas while ignoring the overwhelming majority of scientific knowledge which does not.

I did find a quote in the preface to Burnett’s book that I thought especially apt as it relates to the fuzzy thinking and elastic concept of “truth” that is embedded in homeopathy.

Truth is not Truth save only to the Infinite; to the mind of mortal man Truth is not necessarily Truth, but only that which appears to be true.

The speaker for this session is a rabid anti-vaccine activist who makes no attempt to hide the faith-based and unscientific philosophy that underlies her approach. Dr. Jordan is the owner and author of the web site and book Mark of the Beast Hidden in Plain Sight: The Case Against Vaccination. Here is a sample of the rhetoric from her site.

WE SHOULD REWRITE THE BOOKS OF MEDICINE TO REFLECT THE UNDERSTANDING THAT DISEASE HAS EVOLVED FROM THE VERY USE OF VACCINES.

NEVER SHOULD WE HAVE ALLOWED THE INNOCULATION OF POISON, THE GRAFTING OF MAN AND BEAST. NOW WE ALL CARRY THE SCAR, OF MEDICAL SUPERSTITION THE GENETIC PLAGUE OF INQUITY

The purpose of putting the Mark of the Beast together was to provide education for the reader or listener to a very important quest that apparently has been going on from the beginning of the illusion of time….conventional medicine [is] not the direct path to true healing and wellness…true health and wellness comes from a very natural setting and one from the relationship of the individual in balance with the earth and all of the treasures a healthy ecosystem has to offer…The important ingredient everyone also needs is right relationship with the other living organisms of the environment we share, respect for each other and the most holy relationship that of the one with the intelligence that designed this most wonderful system. Our fall from right relationship is as much responsible for disharmony and disease as is the turmoil the daily disturbance this imbalance maintains…Vaccines and drugs are at odds with the intelligence of the almighty design and getting back to the garden means getting back to the natural form…

If this kind of thinking, tracing all illness back to the Fall of Man and characterizing vaccines as inimical to God’s plan, is part of the “science” of homeopathy, then clearly the word “science” is not being used in anything like the usual sense. In fact, such a use is outright dishonest.

Richard Pitcairn –“Why Medicine Is Not Scientific: The impact of Quantum Physics“

We learn in homeopathy that there can be obstacles to cure, influences on the patient that interfere with their optimal response to the remedy. Usually they are factors like foods eaten, stimulants used, drugs taken, emotional upset. Another angle, not usually considered, are the obstacles to cure that come from two other directions — the client’s psychological state which subtly resists progress and also the interferences of emotional reaction in the practitioner. We will explore some of the most common patterns we will see in progress and consider how best to deal with them.

This presentation is at least a bit more straightforward in its rejection of science, though of course that adds to the overall inconsistency of including it in a program called “The Science of Homeopathy.” Quantum physics is much beloved of proponents of unscientific or pseudoscientific theories. So much so that the invocation of it is one of the key warning signs that one is peddling nonsense. For one thing, it is counterintuitive, seeming to invalidate the well-established laws that govern the behavior of time and matter and which we have evolved to intuitively understand. The implication is that if an established, legitimate science such as quantum physics has found exceptions to the rules of basic logic and the established laws of pre-quantum physics and chemistry, then any counterintuitive theory no matter how wacky must be at least possible.

The flaw in this reasoning arises from another characteristic of quantum physics which also makes it much beloved of CAM advocates; it is difficult to understand. Quantum physics is a hard science in both senses of the word: objective and quantitative and also difficult. It is inherently mathematical, and those of us without advanced degrees in the appropriate domains of physics or mathematic can only understand it in a superficial, metaphorical way. This allows us to promote almost any mystical concept and justify it as “scientific” under the umbrella of quantum physics.

Unfortunately for homeopathy, the oddities of quantum physics, such as entanglement or “spooky action at a distance” only apply at subatomic scales, not at the macroscopic level of ordinary life. They do not validate mystical theories about life force and energy, and they certainly do not support notions of “water memory” and other pseudoscientific attempts to justify selling pure water as if it were medicine.

I’m not sure exactly what Dr. Pitcairn will say in his talk, but the supposed relationship between legitimate quantum physics and vitalistic homeopathic theory has examined been comprehensively debunked many times (here, for example). I would suspect Dr. Pitcairn’s arguments, and the problems with the, to be similar, though of course I can’t be sure.

Sara Fox Chapman – “Hyperthyroidism:  Efficacy, Safety and Pitfalls of Homeopathic Therapy – Six Cases”

Wendy Jensen -“Homeopathy and Feline Urinary Tract Disease”

Wendy Jensen -“Building our Veterinary Homeopathy Literature Base”

These presentations illustrate another superficial resemblance between authentic science and what groups like the AVH present as science. From their brief descriptions, they all rely on case series as their primary, or only form of evidence.

A case series is essentially a collection of individual anecdotes. When used in conventional medicine, a case report or series is intended to illustrate something unusual or unexpected. This may be merely a curiosity, as in most cases, or it may suggest a new idea to be pursued. Case reports and series do not prove anything. They are subjective descriptions of cases that grab a clinician’s interest, not planned controlled, objective research. Another word for case reports is, of course, anecdotes, and as the old cliché goes, the plural of anecdote is anecdotes, not data.

Of course CAM proponents love case reports because they can select those stories that seem consistent with their ideas and present those particular facts that support their argument. Unfortunately, there is no guarding against ignoring those cases or facts that contradict their ideas, and confirmation bias virtually guarantees this will happen with case reports, which is one of the reasons they are not considered proof of anything in real medical science.

Homeopaths in particular rely on case reports because it fits their notions of individuals as snowflakes so unique that no population-based research could ever tell us anything useful about how to care for an individual. The fact that population level research, despite its undeniable limitations, has led to all the medical advances of the last 200 years, including saving billions of people from death and disease, doesn’t seem to register with people making this argument.

So while presenting case reports and case series as if they represented legitimate scientific validation of their ideas, these speakers are simply dressing up the old fashioned anecdote in a white coat and illustrating their fundamentally unscientific approach.

Shelley Epstein – “Evidence Based Homeopathic Veterinary Medicine”

Research supporting the basic science and clinical efficacy of homeopathy is vast and growing. We will review selected studies in basic sciences like biology and physics that show activity in infinitesimal doses. We’ll then discuss noteworthy clinical trials, predominantly from the human side. We’ll look at provings from a 2011clinical trial meets Samuel Hahnemann perspective, the case report, randomized clinical trial (RCT), and politically-charged meta-analysis from perspectives unique to homeopathy. By the end of this lecture, you’ll be able to cite numerous reasons why the statement “There are no studies showing homeopathy works” is false; and you’ll see what it takes to write a case report or design a RCT for publication.

The most sophisticated of these attempts to present homeopathy as based on solid science is this presentation, which the speaker also gave in January, 2011 at the North American Veterinary Conference. Dr. Epstein provides an articulate review of the theoretical foundations of homeopathy and then tries to present a comprehensive refutation of objections on multiple levels, including basic theory, in vitro and laboratory animal research, caser reports, and clinical trials. I respect both the thoroughness of her presentation and the attempt to systematically apply an evidence-based medicine frame to homeopathy.

I think it is clear, however, that the factual details of her defense are mistaken and her conclusions incorrect. She selectively chooses research, and elements of individual studies, that appear to support the claims of homeopathy, assumes the truth of many debatable propositions, and ignores the much larger quantity of evidence against her claims. It is, as I said, a sophisticated defense of homeopathy as a legitimate science, but not a persuasive one.

I will try to go through her presentation in some detail to show why the evidence does not actually support her conclusions. Most of the specifics have been addressed elsewhere many times, so I don’t intend to rewrite the book but simply to point out the major flaws in reasoning or fact. For a more thorough treatment of the problems with Dr. Epstein’s approach, see the resources below.*

Principles of Homeopathy

1. Like Cures Like (or in fancy Latin similia similibus curentur):
This “discovery” on the part of Hahnemann is nothing more than a restatement of the principle of sympathetic magic, the idea that things which resemble one another in some superficial way must be meaningfully related and that one can influence the other. It is the basis for the notion that ground up rhino horn can provide virility, because the horn has some resemblance to a penis. Hahnemann’s version of the idea was that if you take a substance and it causes certain symptoms, then it can be used as a cure for these symptoms once processed in specified ways.

It’s a childish conception of the world, and really quite arrogant in its assumption that how things appear to humans must represent some deep truth about reality. In any case, there is no legitimate evidence that it is true, though of course some accidental correspondences can sometimes be found to perpetuate the myth. Which is likely how the whole idea started, through so-called “provings.”

2. Drug Provings or Pathogenetic Trials:
The concept of provings is another of Hahnemann’s inventions, elaborating on the principle of sympathetic magic. He (or later other volunteers) would take an unspecified amount of a substance and record in detail every experience, sensation, or symptom they experienced afterwards. Subjectively perceived patterns in these reports were then used to define what symptoms the substance could be expected to cause, and thus what it could be used to treat. For the late 19th century, this was reasonably systematic observation compared to many other contemporary medical practices. Today, it is a crude, unreliable practice that deserves to be abandoned.

Attempts to demonstrate the accuracy of traditional symptoms attributed to homeopathic remedies have not generally been successful, and there is great inconsistency between the evaluation of symptoms reported in supposed provings. Since homeopaths revere historical figures, I shall defer to Oliver Wendall Holmes, who described quite clearly the ridiculous logic of “pathogenetic trials” in 1842.

…the common accidents of sensation, the little bodily inconveniences to which all of us are subject, are seriously and systematically ascribed to whatever medicine may have been exhibited, even in the minute doses I have mentioned, whole days or weeks previously.

To these are added all the symptoms ever said by anybody, whether deserving confidence or not, as I shall hereafter illustrate, to be produced by the substance in question.

3.  Potentization Via Dilution and Succusation:
Another of Hahnemann’s counterintuitive epiphanies was the idea that diluting a substance extremely, often to the point where none of the original substance can be detected at all, and then agitating it makes it an effective medicine. While the original substance on which a homeopathic remedy is based might cause symptoms in a proving, if it is sufficiently diluted it will no longer cause these symptoms in healthy people. Up to this point, the idea is rational, and in the early days of homeopathy patients treated with such remedies may often have done better than conventionally treated patients, who were bled and given all sorts of random toxic remedies. Pure water is not medicine, but it isn’t harmful either.

But Hahnemann goes off the rails with the idea that dilution not only made the remedies safer but more potent. Only if, of course, they were agitated in the proper way. As the speaker says, ” In making these dilutions, Hahnemann rigorously pounded the solution on a leather-bound book. His thinking was to evenly distribute the material throughout the solution. This evolved into the process of dynamization, or potentization.”

Dr. Epstein, to her credit, directly addresses the issue of homeopathic dilutions that are so extreme that it is impossible by all established laws of physics and chemistry, “no material substance is expected to be found in a solution.” Her answer to this objection is to refer to a body of research on the subject of “water structure.” She cites many complex tests done on homeopathic solutions, such as thermoluminescence, nuclear magnetic resonance, electron microscopy, and so on to show that the water in these solutions has measurably different structural properties than ordinary water. I’ve written about the subject of magic water before, and while like Dr. Epstein I am a veterinarian, not a physicist or chemist, I am convinced that all these fancy tests fail to add up to a consistent, repeatable, measurable difference between homeopathic solutions and regular water that could possibly be imagined to have biological relevance. These claims have been addressed by others (for example here and here) and in general the physics and chemistry research has demonstrated only that the structure of water at the molecular level is complex and interesting. It has not demonstrated that ultradiluting and shaking water generates stable, biologically relevant  changes in water molecules that turn the water into medicine.

4. In vitro Studies:
A number of studies have been conducted, usually by dedicated believers in homeopathy, to see if homeopathic preparations have measurable effects on cells in test tubes. This would not, of course, prove clinical benefit, but it would at least suggest something other than mere water was present. Most of these studies are published in journals like Homeopathy and The Journal of Complementary and Alternative Medicine, which exist solely to generate the appearance of scientific legitimacy for CAM research that cannot meet the standards of mainstream journals. Thes journals rarely publish any negative results of tests of homeopathy.

But some studies have seemed convincing enough to make it into high-quality journals, including the notorious article in Nature by Jacques Benveniste. Dr. Epstein mentions Benveniste’s study, but apart from a vague reference to a “pseudo-scientific highly political affair” associated with it, ignores the fact that a thorough investigation showed the results to be due to uncontrolled bias and sloppy methodology.

Since then, most such studies have been published in dedicated CAM journals such as those mentioned above and have not been subjected to the kind of rigorous independent review that identified the fatal flaws in the Benveniste study. So while the research mentioned has many of the trappings of legitimate science, it exists largely in a parallel homeopathic universe where it does not have to face skeptical scrutiny.

Despite decades of research that has generated substantial evidence against the claims of homeopathy, I cannot say with absolute certainty that this research may not one day turn up something meaningful, but I think the reasons for doubt are greater than the reasons for hope. And any gems of truth these studies do uncover must still survive the same gauntlet of attempts by skeptics and independent researchers to validate them before they deserve to be accepted as legitimate. As of now, this has not happened, and these claims do not merit this acceptance.

5. Hormesis:
Dr. Epstein epitomizes the bizarre joining of claims to scientific legitimacy with an utter rejection of scientific method and philosophy in her section on hormesis and the mechanism of action of homeopathy. She quotes Hahnemann reverentially and extensively, apparently to make the point that understanding the scientific mechanisms of hoeopathy’s supposed clinical effects isn’t really necessary, but that as it happens Hahnemann’s mystical metaphorical explanations were a prescient vision of what science has since discovered anyway.

In the latter part of the 20th century, conventional medicine has emphasized understanding the mechanism of action of medicines before clinically utilizing a therapy. Complementary/Alternative therapies often suffer from a lack of this understanding, a deficit that has been cited as a reason for avoiding such therapies…In the Organon of the Medical Art, Hahnemann laid out all the rules necessary for successful prescribing in homeopathic practice. The symptoms of the sick patient gave all the clues needed to prescribe, and all that was needed to understand in the drug was discovered in the provings. Hahnemann said:

“This natural law of cure has authenticated itself to the world in all pure experiments and all genuine experiences; therefore it exists as fact. Scientific explanations for how it takes place do not matter very much and I do not attach much importance to attempts made to explain it.”

Regarding the method of action of remedies, Hahnemann said, “Eachmedicine, alters the life force more or less and arouses a certain alteration of a person’s condition for a longer or shorter time. This is termed the initial action. While the initial action is a product of both the medicinal energy and the life force, it belongs more to the impinging potence [of the medicine]. Our life force strives to oppose this impinging action with its own energy. This back-action belongs to our sustentive power of life and is an automatic function of it, called the after-action or counter-action.”

These brilliant observations by Hahnemann almost two centuries ago are being verified by scientific studies today.

The supposed verification of Hahnemann’s vitalistic theories of mystical life forces is the concept of hormesis. In brief, hormesis is the notion that a high dose of radiation or a toxin may generate the opposite response as a low dose. The notion is controversial in that while such a dose response relationship in laboratory settings can be shown for a variety of toxins, it is not clear that it is a real or biologically meaningful phenomenon. Extensive research on the concept of hormesis applied to radiation has generated little convincing evidence to support claims that low doses of radiation can have beneficial health effects. Homeopaths love the idea of hormesis because it seems to align with their belief that something poisonous in high doses can be beneficial in low doses.

One problem here is that hormesis is not generally accepted as a true and meaningful phenomenon that predictably affects the health of living organisms, so using the concept to justify homeopathy is simple taking a questionable idea and using it to support an even more doubtful one. However, even if hormesis turns out to have some real biological relevance, it doesn’t really translate in “homeopathy works.” The low doses of toxins in studies on hormesis are at least measurable doses, unlike the complete absence of any “material substance” in homeopathic preparations, so the whole notion of magic water memory would still have to be true for homeopathy to work.

Another problem is that the relationship between specific substances and the symptoms they are used to treat is only based on the subjective and unsystematic observations of “provings,” so even if solutions that had once contained some of these substances could somehow have medicinal effects, we don’t have a consistent and reliable way to select specific remedies for specific problems, just homeopathic intuition.

And finally, the symptoms a patient reports and the process by which the homeopath decides which are important and which aren’t and which remedies to use are thoroughly subjective and inconsistent. Like chiropractors, homeopaths do not reliably and consistently identify the same problems or the same treatments for individual patients.

So even if there were something to hormesis, which seems doubtful, the use of homeopathic remedies to treat disease still fails multiple other tests of logic and consistency. Of course, when faced with these challenges to their claims, homeopaths usually fall back on the claim that, “Well, I don’t know how it works, but it works.” So is there anything to this claim? Despite all its implausibility and lack of a clear, logical theory, does homeopathy actually work reliably in clinical studies?

6. Claims of Clinical Benefit:
Dr. Epstein presents many claims and arguments that homeopathy has a real, measurable benefit despite all the problems with its theory and methods. The first of these are claims that homeopathic “vaccines,” called nosodes, and homeopathic remedies have been effective in preventing or treating infectious disease epidemics. Claims are for regarding successful use of homeopathy to reduce mortality during the 1918 flu pandemic and to combat leptospirosis associated with flooding in Cuba in 2007, and for other epidemics. The specifics of the studies and claims have been discussed by others (Cuba 2007, Cuba 2007, 1918 Flu Epidemic), but there are several obvious problems with them.

For one thing, they are often based on uncontrolled reporting and case selection by proponents of homeopathy. Undoubtedly, homeopaths in 1918 claimed a very low mortality from the flu, without objective statistics (which are, shockingly, not available from 100years ago), there is no way to verify these claims. And subsequent studies have, as usual, been conducted by homeopaths, published in journals dedicated to alternative medicine, and not replicated or rigorously reviewed by anyone not already a believer in homeopathy. This lowers the reliability of these reports significantly and justifies significant skepticism of them. Also, nosodes as a preventative for infectious disease have been studied and have failed to demonstrate their effectiveness under controlled conditions. So the impression of effectiveness here is, once again, highly dependent on uncontrolled clinical observations and self-reporting by homeopaths.

Dr. Epstein then goes through a lengthy discussion of randomized clinical trials (RCTs) versus case reports to make the point that RCTs are not appropriate for homeopathy and aren’t all that reliable anyway. This is a form of special pleading that essentially says “Because conventional methods of study don’t support my approach, the methods must be inappropriate.” The same claim is made for why scientific studies haven’t confirmed ESP and other psychic phenomena, the effectiveness of prayer as a medical therapy, and essentially any implausible idea that conventional scientific methods don’t validate.

There is no question that RCTs have many limitations and flaws, and some of those that Dr. Epstein points out are true problems. This does not, however, have any bearing on the fact that overall as a method they work better than the subjective, anecdotal methods homeopaths prefer and have revolutionized health and health care to an unprecedented degree. It is a philosophical point, of course, but I hold the view that reality is as it is regardless of how we see it or wish it to be. Our ability to know it is limited by the flaws in our own perception, memory, and reasoning. Science has many weaknesses but, to paraphrase Winston Churchill, it is the worst possible system except for all the others that have been tried. Anecdote (dressed up as case reports or “case-based reasoning” though it may be) has led to many varieties of error and little real progress in medical care throughout human history, so to argue that it is as good as or better than the scientific method is to deny the manifest reality illustrated by this history. It is, ultimately, a weak excuse to claim that homeopathy, which has failed by the standards science applies to conventional medicine, deserves to be judged y what she calls “special considerations,” a code for weaker standards of evidence..  

All of that said, there have been many clinical trials involving homeopathy, and homeopaths in general cite them freely as validating their methods when they appear positive. Many have methodological flaws that call into question their conclusions (for example, this arthritis study and this study of bovine mastitis). Of course, the same is true of studies of conventional therapies, but the point is that no single study definitively proves or disproves a single clinical hypothesis, much less an entire therapeutic approach. The balance of the clinical trial evidence over decades is clearly, and definitively against any meaningful benefit from homeopathic treatment. The references below discuss many of the systematic reviews, meta-analyses, and other large-scale analyses of the sum total of the evidence.

The trends in the clinical trial evidence are the same as is often seen for implausible or dubious therapies. Smaller, poorly designed trials, trials published in journals dedicated to promoting homeopathy or alternative medicine are more likely to report positive results (even, sometimes, when a close look at the data and statistical analysis doesn’t support these conclusions). Larger studies with better quality in mainstream journals and not conducted or funded primarily by homeopaths tend to show negative results. When looked at in total, the evidence clearly does not support claims that homeopathy is a proven beneficial clinical therapy.

So while Dr. Epstein is correct to say that the claim “There are no studies showing homeopathy works” is false, she is incorrect in her conclusion that the evidence, from the theoretical and basic science level, trough the in vitro level, and including the clinical research level shows homeopathy does work. The evidence on all of these levels fails to support the theoretical or practical claims of homeopathy, and it does not justify presenting this essentially faith-based treatment as if it were “science.”

Conclusions
This one conference seems, from the presentations being offered and the information available by and about the presenters, to illustrate clearly the love/hate relationship homeopathy has with science. Homeopaths disdain the scientific methods that have failed to support their claims for decades, and they make many arguments that these methods are inappropriate, that homeopathy can only be judged by its own standards, or that the whole enterprise of understanding health and disease through scientific methods is too flawed to be relied on. Yet they simultaneously crave the legitimacy that comes from being perceived as practicing a legitimately science-based form of medicine, and they go to great lengths to adopt the trappings of true science and claim science validates their approach. Some of the arguments are bizarre and seem out of touch with reality, others are mere confused New Age mysticism cloaked in the language of science, and a few, like those of Dr. Epstein, are articulate, informed and thoughtful (though ultimately still self-serving and false). Taken as a whole, they present a picture of a confused and conflicted attempt to be both special and different and yet accepted and respected by the mainstream. Ultimately, what matters is what the evidence tells us about the theories and clinical claims of homeopathy, and this evidence is still solidly, consistently against these these theories and claims.

 

* The Homeopathy Series:

Homeopathy and Evidence-Based Medicine: Back to the Future – Part I

Homeopathy and Evidence-Based Medicine: Back to the Future – Part II

Homeopathy and Evidence-Based Medicine: Back to the Future–Part III

Homeopathy and Evidence-Based Medicine: Back to the Future Part IV

Homeopathy and Evidence-Based Medicine: Back to the Future Part V

UK House of Commons Science and Technology Committee Report on Homeopathy 

Snake Oil Science by R. Barker Bausell

Trick or Treatment: The Undeniable Facts about Alternative Medicine by S. Singh and E. Ernst

Posted in Homeopathy | 16 Comments

SkeptVet Survey

Posted on April 11, 2011 by skeptvet

In the nearly two years I have been producing this blog, there have been a lto of changes. The visual format, links, and organization structure has changed. I have changed, and hopefully improved, my writing style and content. And the number of readers (or at least hits) has grown from a few dozen a day to a couple hundred.

My purpose for doing this, unpaid and in my severely limited spare time, is to create a useful resoource for pet owners and veterinarians, and to bring a scientific, skeptical, fact-based approach to evaluating potential veterinary therapies. However, it is not always easy to know when I am succeeding and when I am not. So I have created a short survey to find out a little more about who is reading this blog and what you think about the fromat and, most improtantly, the content. Of course, it’s easy for those who disagree with my approach entirely to simply dismiss in all the ways I illustrated recently. But for those who do find the content on this site useful, or who feel they could if some changes were made, I ask that you take a few moments to give me some feedbakc and suggestions to make what I do here more useful for you.

Please, let me know what you think by taking the SkeptVet Survey.

April 17, 2011: The SkeptVet Survey is now closed. Thanks to all who participated!

Posted in General | 3 Comments

Veterinary Probiotics: Sloppy Labeling and Poor Quality Control

Posted on April 4, 2011 by skeptvet

Probiotics are one of the therapies I frequently discuss here that I suspect may actually have some benefit(1, 2), though the evidence does not currently support routine clinical use. However, as with most herbal remedies, supplements, and nutraceuticals, a lack of meaningful government regulation (3, 4) allows these products to be marketed with no reasonable supporting clinical evidence and despite potential risks and significant problems with quality control (5, 6).

A new study illustrates why even a potentially promising therapy like probiotics is likely to end up as no more than a collection of dubious commercial products without a strong commitment to evidence-based research and development enforced by adequate regulatory oversight.

Weese, JS. Martin H. Assessment of commercial probiotic bacterial contents and label accuracy. Canadian Veterinary Journal 2011;52:43–46.

The authors purchased and evaluated 25 commercial veterinary probiotic products and evaluated both the labels and the contents. A medicine should have a clear label that indicates what the active ingredient is, how much of it is present, when it expires, and other such information that the consumer needs to evaluate the product and use it safely and effectively. Even though there is not yet much clinical research to support the benefits of probiotic therapy, the marketers of such remedies could at least ensure accurate labeling of their products. But that appears to be the exception, not the rule.

Of the 25 products tested, only two had accurate labels that identified the organism (and spelled it correctly) and actually had in the preparation what the labeled claimed was in it. (Interestingly, one of these was Prostora, from the IAMS company, which is also the only veterinary probiotic product for which there is a reasonably good quality clinical trial looking at efficacy. And no, I don’t get any money from them.)

Only 60% of the products indicated on the label how many bacteria they contained in a way that made any sense. Three products used a used names for an organism that doesn’t exist as well as a real name to describe their active ingredient. 32% of the labels spelled the name of the bacteria incorrectly. This may seem like a minor error, but the level of attention to detail required in the manufacture of medicine should be higher than is expected in ordinary activities. How much confidence would you have in an antibiotic, heart medication, or other drug if the manufacturer couldn’t even spell the name of it correctly?

Only 27% of the products had as much or more of the bacteria in them as was claimed on the label. And while there is no established “dose” for probiotic bacteria, since there hasn’t been enough research to determine what this would be, the studies that have been done to test if probiotic bacteria can colonize the intestines after being taken orally have used doses which could not possibly be achieved by most of the products tested in this study.

This study does not directly address the question of whether or not probiotics in general are actually safe and beneficial for clinical use in dogs or cats. But it does highlight that even if they are, most of the veterinary probiotics currently available are inadequately or improperly labeled and do not have meaningful numbers of active bacteria in them anyway. A lack of research evidence combined with a lack of effective regulation, due primarily to the lobbying efforts of the supplement industry, undermine the potential value of these therapies and make confident routine use of the products now on the market nearly impossible.

If the industries that produce and sell these products wish to continue to discourage government interference with their activities, then they should bear the burden of ensuring accuracy in labeling and quality control for their products. And if they truly care about the welfare of our animal companions, rather than only about profit, then they ought to fund the kind of objective, high-quality research that would tell us if these products are of any real value. Some of these companies are doing this, but clearly most are not.

Posted in Herbs and Supplements | 4 Comments

Raw Diets for Pets: Still No Evidence of Benefit but a Real Risk of Harm

Posted on April 4, 2011 by skeptvet

I’ve written before about raw diets for pets, and at the time my conclusions were these (see the previous articles for details 1, 2):

1. The theoretical arguments presented to support feeding raw diets to dogs and cats are mostly nonsense.

            a. Raw diets are “natural”

            b. Dogs and cats can’t digest grains

            c. Raw diets contain needed enzymes or “life energy”

            d. Commercial diets are full of “toxins” or otherwise unhealthy

2. There is no evidence to show a benefit to feeding raw diets apart from individual anecdotes and testimonials, which are not reliable.

3. There is limited evidence of potential harm from raw diets, including infectious diseases, parasitism, trauma from bones, and nutritional deficiencies.

A new review of the literature concerning raw diets of animal companions appeared in January in the Canadian Veterinary Journal, and it confirms these concluions.

Schlesinger, DP. Joffe, DJ. Raw diets in companion animals: A critical review. Canadian Veterinary Journal 2011;52-54.

The authors begin by reviewing some of the reasons people are interested in feeding such diets. These include concerns about the safety or nutritional adequacy of commercial diets and a desire to feed our pets in ways we perceive as healthful, just as we wish to feed ourselves and our children. These are, of course, legitimate motives. But they don’t make the mythology behind raw diets any less false nor remedy the lack of evidence for safety or benefit. The fact remains that the best, most effective choices in the care of our pets are those we make based on sound scientific evidence.

In this article, the evidence concerning raw diets is evaluated according to a scale of quality which is described in the article and which is commonly used to evaluate research evidence. In this scale, Level 1 evidence would consist of multiple high quality studies which agree or which have unequivocal results. No Level 1 quality evidence was identified for either potential risks nor benefits to raw diets.

Levels 2 and 3 evidence would be data from fewer or slightly lower quality population studies. Level 4 evidence would be from poor quality group studies or simply collections of uncontrolled case reports. And Level 5 evidence is essentially just opinion or extrapolation from basic theoretical principles.

The authors found no Level 2 or 3 evidence for a benefit from raw diets. The only published study at all cited concerning raw diets and health was a survey of owners in Australia which reported that over 98% of owners thought their pets were healthy, and between 10-16% of the pets these individuals owned ate some raw food. Clearly this says absolutely nothing about the relationship between health and feeding of raw diets, and it is quite a stretch to even view it as relevant to the question.

The authors found a Level 5 paper which reviewed the literature in humans concerning the question of whether enzymes in raw foods increased the nutritional quality of this food for humans. This paper concluded that there is no evidence of harm from the absence of such enzymes in cooked food and not enough information available to identify if the presence of such enzymes has any real significance.

Another Level 5 article was discussed which looked at the effect of raw foods (not meat) on cardiovascular disease risk in humans and concluded that some risks might decrease and others increase with such a diet. Obviously, there is no reliable, meaningful information in either of these articles to support benefits from raw diets fed to dogs and cats.

No Level 2-3 evidence was identified concerning nutritional risks from feeding raw diets. Several case reports were found (Level 4 evidence) of pets who suffered from nutritional deficiencies or excesses from being fed raw diets, and a survey of 5 raw diets, both commercial and homemade, identified such deficiencies or excesses in all of the diets.

Level 2, 3, and 4 evidence was found to support that raw diets present a significant risk of infectious disease for pets fed these diets and their owners. Many raw diets, both commercial and homemade,  test positive for E. coli and Salmonella, potentially deadly food-borne bacteria. Both dogs and cats fed such diets have been shown to shed these organisms in their feces. Both pets and humans in contact them have developed active infections with these bacteria and some have become ill as a result. Freezing and standard cleaning and disinfecting practices do not effectively control this risk, and some of the organisms identified in these diets were resistant to typical antibiotics used to treat people infected with them.

So the conclusions I came to two years ago have not changed. There is no top quality evidence concerning the potential risks and benefits of feeding raw diets to dogs and cats. There is no evidence of any level other than mere opinion and anecdote  to support claims that these diets are beneficial. There is, however, reliable evidence for real and significant risks associated with these diets. At this point in time, then, the balance of the evidence does not support feeding raw diets. Until and if a benefit can be shown by objective, scientific research, that outweighs the known risks, such diets should be avoided.

Posted in Nutrition | 15 Comments

Veterinarians and Evidence-Based Medicine

Posted on March 29, 2011 by skeptvet
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Early in 2010, the Practitioner Committee of the EBVMA conducted a survey of practicing veterinarians in the United States concerning their familiarity with the terms and concepts of evidence-based medicine and their attitudes towards it. The survey instrument was based on those used in published studies involving medical doctors and nurses. There were significant challenges in obtaining an adequately large, representative sample of U.S. practitioners. Ultimately, 5000 veterinarians were invited to participate via a printed letter, and 119 completed web-based questionnaires were completed, a response rate of about 2.5%. While this does not permit meaningful generalizations to be made about the population of interest, the project was, at the least, an instructive pilot study, and further studies are planned.

The only way to preserve the figures and formatting of the results summary was to attach it as a .pdf to this post, which can be viewed using the link below.

Survey of Veterinarians’ Knowledge and Attitudes Concerning Evidence-Based Medicine

Posted in General | 4 Comments

Causes of Death for Dogs by Breed and Age: An Important New Study

Posted on March 28, 2011 by skeptvet

It has long been recognized that there are patterns in the causes of death for our dogs. Younger dogs die from different things than older dogs, and different breeds have greater or lesser risk of dying from different causes. Understanding these patterns is helpful in many ways. It helps owners know what sort of problems to watch out for in their pets. It helps veterinarians focus on the most likely cause of a particular dog’s illness. And most importantly it guides us in identifying specific risks for individual patients and taking action to minimize these and prevent or delay illness and death.

Causes of death also change over time, and they are influenced by how we care for our pets. Nutrition, vaccination, neutering, confining pets rather than letting them roam, and many other factors under our control influence the causes of mortality in our pets. But the relationship between these things and what our pets die from isn’t always what we think it is. There is a lot of mythology and misconception out there about the risks our pets face, and it requires careful, objective, and laborious research to identify the true mortality patterns that will then let us identify the best ways to reduce these risks.

A new study from the University of Georgia makes a major contribution to our understanding of the causes of mortality in different breeds of dog.

Fleming JM, Creevy KE, Promislow DE. Mortality in north american dogs from 1984 to 2004: an investigation into age-, size-, and breed-related causes of death. J Vet Intern Med. 2011 Mar;25(2):187-98.

This study  involved sifting through 20 years of records from the Veterinary Medical Database, a collaborative resource that includes records from 27 North American veterinary medical school teaching hospitals. Causes of death for over 75,000 dogs in this database were identified of the relationships between cause of death, age at death, and breed were analyzed. The results are occasionally surprising, or fill in gaps where no previous data were available, but they also often confirm recognized patterns long established for humans and previously demonstrated or expected for our dogs.

Causes of death were categorized in two ways: by the organ system involved, and by the category of disease (called the “pathophysiological process”). This allowed the investigators to identify both what specific organs in the body were most often involved in fatal disease for individuals of each breed and also what kind of disease led to death. The figure below shows the percentage of dogs in the study whose deaths could be attributed to specific kinds of disease of disease in particular organs, both for juvenile animals (less than 1 year old at death) and adults (over 1 year old at death).

Figure 1. Proportion of deaths attributable to each organ system (OS) and pathophysiologic process (PP) category for juvenile (up to 1 year, A and B) and adult (1 year or greater, C and D) dogs. Among 9,859 juvenile dogs, 2,792 were unclassified for OS (A, n = 7,067) and 3,004 were unclassified for PP (B, n = 6,855). Among 64,697 adult dogs, 12,374 individuals were unclassified for OS (C, n = 52,323) and 23,438 individuals were unclassified for PP (D, n = 41,259).

Overall, this shows that the organ systems in which fatal disease arises are remarkably similar for young and old dogs. And the relative contribution of particular organ systems to mortality is fairly even, though the gastrointestinal, nervous, and musculoskeletal systems tend to be involved more often, and the skin, eyes, liver, and glandular systems are less commonly involved. The figure also illustrates that the causes of death are quite different for dogs of different ages. Young dogs are overwhelming likely to die of infection, trauma, or congenital disease, whereas cancer (neoplasia) is by far the greatest cause of death in older dogs. 

The other figure that I think most effectively illustrates the findings of this study, shows the frequency of particular causes of death at different ages. This contains, in some ways, the same information as the chart above, but it helps to clarify quite nicely what I believe is a key pattern.

Figure 3. Relative frequency of causes of death by pathophysiologic process (PP), as a function of age (years) for all breeds with more than 100 representatives (n = 46,720, excluding 25,656 individuals unclassified for PP)… Estimates are provided for each of 10 age-classes, with points connected by a solid line to highlight any obvious age-related trends. Dashed lines represent 95% confidence intervals.

Again, clearly death from infection, trauma, and congenital diseases are by far the most common before about 2 years of age, and the risk of cancer rises steadily with age until it peaks at about 10 years, Interestingly, the cancer risk overall then drops after this age, though it is still the most common cause of death.

The paper also contains a lot of information about the most common causes of death for many individual breeds, which it would be cumbersome to reproduce here. Some patterns are familiar to many veterinarians, such as the relatively higher incidence of cancer deaths in Boxers and Golden retrievers than in many other breeds, and the high frequency with which small breed dogs suffer from neurologic and cardiac disease. However, other patterns have not previously been identified in scientific research, such as the high rate of cancer deaths in Bouvier de Flandres dogs and the relatively high rate of cardiovascular causes of death in Fox Terriers. More detailed and specific research will be required to sort out the causes, and possible treatment or preventative interventions, involved in these breed-specific patterns. However, this study gives us many new and potentially useful targets for such further investigation.

So what sort of useful conclusions can we draw from these data? Well, we can say, for example, that cancer is a disease associated with aging, and it is far more common in older dogs than in younger dogs. And, despite the claims sometimes made that it is due to chronic exposure to toxins in commercial dog food, vaccination, and so on, the fact is that the incidence of cancer increases with age in all breeds regardless of differences in lifestyle, and that it also becomes less common in the oldest individuals. If it were simply a matter of the risk going up the longer dogs were exposed to such purported environmental toxins, then the risk should continue to rise steadily with age. However, it is well established in humans that there are genetic predispositions to cancer as well as age-associated increases in risk, and that those individuals who survive to extreme old age are relatively less likely to get cancer since they appear to have protective genetic constitutions. The variation in cancer risk by breed and the age-associated patterns seen in this study show a similar pattern.

In short, cancer occurs largely as a result of the interaction between genetic risk factors and age, with lesser contributions from environmental influences that also interact with genetic factors. Cancer is what you die of if you’ve avoided dying of infectious disease and trauma and lived long enough to get it. The relative increase in cancer as a cause of death in our dogs over the last few decades is a sign of our success in reducing the importance of these other causes, not a damning indictment of our toxic environment or nutritional and vaccination practices.

There are, of course a number of limitations and caveats to the data in this study and the conclusions we draw from them. Perhaps the greatest of these is that the dogs studied were individuals seen at veterinary teaching hospitals. These hospitals typically see the sickest patients and the most complex or unusual cases, since less severe or common problems are often taken care of by private practice veterinarians. And some research suggests that many dog owners do not routinely seek veterinary care at all, much less the high-level care offered at a teaching hospital. So the study population may not be representative of the overall dog population, and the particular causes of death may not accurately reflect those of all dogs, even if the general patterns are the same. If, for example, dogs not seen at teaching hospitals are less likely to have recommended vaccinations or other preventative care, or are less likely to be taken to a vet if injured, then the relative contribution of infection and trauma as causes of death may be higher in the general population than in the dogs in this study.

And the information in this report doesn’t specifically tell us how common specific causes of death are in particular breeds or particular ages, that is the absolute frequency of these causes. To figure that out, we’d need to know something about all the dogs of each breed at each age who didn’t die. The data can only tell us the relative frequency of different causes in each breed. And we can’t yet know about changes in these risks over time, or about regional differences, though the authors are apparently continue to analyze the data to find some of those answers. It will be interesting and useful to see what trends are identified over time in these data. I would expect, for example, that the relative importance of infectious disease as a cause of death would decrease over time as prevention and treatment improve and are utilized by more pet owners. But only time and the hard work of these researchers will tell.

Still, this is an important study which adds significantly to our understanding of the causes of death in our canine companions and which will help guide future efforts to understand these causes and reduce or eliminate those risks we can.

Posted in Science-Based Veterinary Medicine | 30 Comments

A Primer on Medical Cognition

Posted on March 28, 2011 by skeptvet

One subject that I am perennially interested in is the nature of how people in general, and doctors in particular, make decisions and judgments, and how that process can go wrong. I’ve written about the pitfalls of spiraling empiricism, cognitive dissonance, uncertainty and medical decision-making, the Dunning-Kruger effect, why clinical experience is often unreliable, and other aspects of how general human psychology, and the attitudes, training, and approaches of doctors in particular, can lead us to erroneous conclusions and bad clinical decisions. Now a colleague has introduced me to the field of medical cognition, through a dense and often painful-to-read but fascinating and informative article:

Patel, VL. Arocha, JF. Kaufman, DR. A primer on aspects of cognition for medical informatics. J Am Med Inform Assoc. 2001;8:324–343.

There is a lot that I am not qualified to understand or evaluate in the article, particularly as pertains to the details of electronic medical record systems, artificial intelligence, and so on. But some of the insights gleaned from the cognitive psychology literature on how doctors develop decision-making strategies and how these change with education and experience seem very relevant to everyday clinical practice. One pretty established concept is that experienced doctors and those with highly developed skills and expertise are better able to filter out irrelevant information and attend to and classify what is most important in establishing a diagnosis. As the authors put it, research identifies:

…the greater ability of expert physicians to selectively attend to relevant information and narrow the set of diagnostic possibilities…The ability to abstract the underlying principles of a problem is considered one of the hallmarks of expertise, both in medical problem solving and in other domains.

One of the models for how experts achieve this is the concept of schemata:

…mental representations of typical things (e.g. diseases) and events (e.g. episodes of illness)…[which serve] as a “filter” for distinguishing relevant and irrelevant information. Schemas can be considered generic knowledge structures that contain slots for particular kinds of findings (data). For instance, a schema for myocardial infarction most likely contains the findings “chest pain,” “sweating,” but not the finding “goiter,” which is part of the schema for thyroid disease…A function of schemata is to provide a “filtering” mechanism to experts, allowing them to selectively attend to significant information and discard irrelevant clinical information.

Experts process information at a level of abstraction that is most efficient and reduces the burden on memory. Through years of experience, they have learned to conceptualize medical information (e.g., clinical findings from a patient) in terms of constructs…intermediate between the concrete level of particular signs and symptoms and the more abstract nature of diagnoses… In contrast, less experienced physicians tend to process medical information at a more detailed level.

Building these schemata and learning to process the huge amount of available information (history, physical examination findings, bloodwork, imaging, etc) efficiently and effectively takes a long time.

This research has shown that, on average, the achievement of expert levels of performance in any domain requires about ten years of full-time experience.

Developing such expertise certainly requires acquiring specific factual knowledge. However, research suggests that the importance of facts in building competence is often overestimated.

Factual knowledge involves merely knowing a fact or set of facts (e.g., risk factors for heart disease) without any in-depth understanding. Facts are current truth and may become rapidly out of date. The acquisition of factual knowledge alone is not likely to lead to any increase in understanding or behavioral change. The acquisition of conceptual knowledge involves the integration of new information with prior knowledge and necessitates a deeper level of understanding…Factual knowledge is inherently more brittle than conceptual knowledge, and this brittleness is most acutely observed in unfamiliar situations.

This certainly accords with my own experience of transitioning from a new graduate to an experience veterinarian. I sometimes feel as if much of the detailed factual knowledge acquired and regurgitated laboriously in veterinary school has left me, yet I am able to identify the important pieces of information in a given case and relate them to relevant criteria for diagnosis or treatment much more easily than new graduates I work with. And, of course, facts are always available to be looked up when needed.

Interestingly, research in the development of expertise does not seem to support the popular, conventional model of how one gets better at a complex skill. For one thing, the process does not seem to be a steady accretion of knowledge and skill, but an erratic, unsteady trajectory. And in many cases, as one shifts from a detailed, algorithm-driven, formalized method to the more efficient, heuristic approach of an expert, one’s competence may actually decline, a phenomenon the authors refer to as the “intermediate effect.”

Cross-sectional studies of experts, intermediates, and novices have shown that, on some tasks, people at intermediate levels of expertise may perform more poorly than those at lower levels of expertise, a phenomenon known as the “intermediate effect.” When novice–intermediate–expert data are plotted…the performance of intermediate subjects (those who are on their way to becoming proficient in a domain but have not reached the level of experts) declines to a level below that of novices…

This literature suggests that human development and learning does not necessarily consist of the gradually increasing accumulation of knowledge and skills. Rather, it is characterized by the arduous process of continually learning, re-learning, and exercising new knowledge, punctuated by periods of apparent decrease in mastery and declines in performance. Given the ubiquity of this phenomenon, we can argue that such decline may be a necessary part of learning.

One theory that occurs to me to explain this, and which the authors don’t appear to consider, is that the fundamental nature of the shift from novice to expert may itself be counterproductive in some ways. Novices tend to follow explicit rules and patterns taught to them for sorting and utilizing information and solving problems. Experts tend to have internalized these rules and often process information and draw conclusions without explicit, conscious awareness of the thought processes involved. While this is inarguably more efficient, it raises the risk of bias significantly. It appears to be well-established that the risk of drawing incorrect conclusions is increased when explicit and objective controls for unconscious bias are not utilized. Barry Beyerstein has created a list of the cognitive biases and errors that can lead to incorrect clinical decisions, and many of these would seem to involve relying on instinct or intuition, which are colloquial labels for exactly the kind of unconscious information processing the authors of this article characterize as the hallmark of an expert (I have adapted and modified this list to suit the veterinary profession).

Human Psychology Even when no objective improvement occurs, people with a strong psychological investment in the pet can convince themselves the treatment has helped. And doctors, who want very much to do the right thing for their patients and clients, have a vested interest in the outcome as well. A number of common cognitive phenomena can influence one’s impression of whether a treatment helped or hurt a patient. Here’s a brief list of common cognitive errors in medical diagnosis. Any of these sound familiar?

a.      Cognitive Dissonance When experiences contradict existing attitudes, feelings, or knowledge, mental distress is produced. People tend to alleviate this discord by reinterpreting (distorting) the offending information. If no relief occurs after committing time, money, and “face” to a course of treatment internal disharmony can result. Rather than admit to themselves or to others that their efforts have been a waste, many people find some redeeming value in the treatment.

b.     Confirmation Bias is another common reason for our impressions and memories to inaccurately represent reality. Practitioners and their clients are prone to misinterpret cues and remember things as they wish they had happened. They may be selective in what they recall, overestimating their apparent successes while ignoring, downplaying, or explaining away their failures. Or they may notice the signs consistent with their favored diagnosis and ignore or downplay aspects of the case inconsistent with this.

c.      Anchoring This is the tendency to perceptually lock onto salient features in the patient’s initial presentation too early in the diagnostic process, and failing to adjust this initial impression in the light of later information. This error may be severely compounded by the confirmation bias.

d.     Availability The disposition to judge things as being more likely, or frequently occurring, if they readily come to mind. Thus, recent experience with a disease may inflate the likelihood of its being diagnosed. Conversely, if a disease has not been seen for a long time (is less available), it may be underdiagnosed.

e.      Commission Bias results from the obligation toward beneficence, in that harm to the patient can only be prevented by active intervention. It is the tendency toward action rather than inaction. It is more likely in over-confident veterinarians. Commission bias is less common than omission bias.

f.      Omission Bias the tendency toward inaction and rooted in the principle of nonmaleficence. In hindsight, events that have occurred through the natural progression of a disease are more acceptable than those that may be attributed directly to the action of the veterinarian. The bias may be sustained by the reinforcement often associated with not doing anything, but it may prove disastrous.

g.     Diagnosis Momentum Once diagnostic labels are attached to patients they tend to become stickier and stickier. Through intermediaries (clients, techs, other vets) what might have started as a possibility gathers increasing momentum until it becomes definite, and all other possibilities are excluded.

h.     Feedback Sanction Making a diagnostic error may carry no immediate consequences, as considerable time may elapse before the error is discovered, if ever, or poor system feedback processes prevent important information on decisions getting back to the decision maker.

i.       Gambler’s Fallacy Attributed to gamblers, this fallacy is the belief that if a coin is tossed ten times and is heads each time, the 11th toss has a greater chance of being tails (even though a fair coin has no memory). An example would be a vet who sees a series of patients with dyspnea, diagnoses all of them with a CHF, and assumes the sequence will not continue. Thus, the pretest probability that a patient will have a particular diagnosis might be influenced by preceding but independent events.

j.       Posterior Probability Error  Occurs when a vet’s estimate for the likelihood of disease is unduly influenced by what has gone on before for a particular patient. It is the opposite of the gambler’s fallacy in that the doctor is gambling on the sequence continuing,

k.     Hindsight Bias Knowing the outcome may profoundly influence the perception of past events and prevent a realistic appraisal of what actually occurred. In the context of diagnostic error, it may compromise learning through either an underestimation (illusion of failure) or overestimation (illusion of control) of the decision maker’s abilities.

l.       Overconfidence Bias A universal tendency to believe we know more than we do. Overconfidence reflects a tendency to act on incomplete information, intuitions, or hunches. Too much faith is placed in opinion instead of carefully gathered evidence. The bias may be augmented by both anchoring and availability, and catastrophic outcomes may result when there is a prevailing commission bias.

m.   Premature Closure A powerful error accounting for a high proportion of missed diagnoses. It is the tendency to apply premature closure to the decision making process, accepting a diagnosis before it has been fully verified. The consequences of the bias are reflected in the maxim: ‘‘When the diagnosis is made, the thinking stops.’’

n.     Search Satisfying  Reflects the universal tendency to call off a search once something is found. Comorbidities, second foreign bodies, other fractures, and coingestants in poisoning may all be missed. Also, if the search yields nothing, diagnosticians should satisfy themselves that they have been looking in the right place.

It may be that there are advantages to the deliberate processes followed by novices, and that the adjustments in these made to achieve speed and efficiency aren’t always exclusively favorable to accuracy. Of course, there is evidence that experts truly are better at arriving at correct conclusions than novices, so the heuristic methods that they develop are effective most of the time. But a key element in encouraging the adoption of evidence-based medicine is inculcating adequate self-doubt. It is clear that explicit, objective methods of analysis are less prone to bias and error than reliance on our own perceptions and internalized and unconscious decision-making processes. This reliance on the explicit and the objective is most critical in controlled clinical research, but it is also a useful process for reducing error in day-to-day clinical practice. So in recognizing and emulating the heuristic practices of experts, we must not neglect to recognize their pitfalls and include tools and methods for compensating for these weaknesses.

Posted in General | 3 Comments

A Review of Reviews of Acupuncture for Pain: Might Work, Might not; Could Kill You, Probably Won’t

Posted on March 27, 2011 by skeptvet

A new review of systematic reviews of acupuncture treatment for pain was recently published in the journal Pain. Basically, a systematic review is a study which looks at primary clinical research studies selected in a comprehensive and pre-determined manner and with explicit standards for evaluation of the quality of the studies included. It is a way of taking a collection of research studies on a single subject and evaluating them objectively to determine what the balance of the evidence overall says about the subject. A systematic review of systematic reviews, then, uses the same objective and explicitly stated methodology to examine multiple systematic reviews on a single subject. This approach sounds pedantic, but it serves to minimize the influence of the reviewer’s bias on the conclusions.

An informal or narrative review, in which an author picks whichever studies they want and evaluates them informally, tends to simply conclude whatever the author originally expected the balance of the evidence to say. A systematic review makes it harder to intentionally or unintentionally select some studies and ignore others in a way that biases the conclusions, or to give greater credence to some studies over others based on one’s preconceptions rather than on objective criteria for quality. Thus, systematic reviews and systematic reviews of reviews, if properly conducted, are the most reliable level of evidence.

This review identified 57 systematic reviews that met the criteria for inclusion in the analysis. The authors were primarily interested in the effectiveness of acupuncture as a treatment for pain and the side effects of acupuncture treatment. The results were mixed.  25 reviews reported a tentatively or clearly positive result, meaning acupuncture appeared to be beneficial for the conditions studied. 32 reviews did not report a positive result, meaning acupuncture appeared no better than placebo for pain. Of the 4 reviews deemed excellent in quality, 2 found a significant benefit and 2 did not. When there were multiple reviews for the same condition, they frequently contradicted each other.

The exact significance of these results is not clear. It could be that acupuncture helps with pain for some conditions but not others, though neither the traditional mystical theories nor more modern neurophysiological theories of how acupuncture is supposed to work would predict or explain that. However, as the authors of the review point out, several recent high-quality research studies hold out some hope of an answer. In these studies, fake acupuncture (applying treatment at random locations, using needles that don’t penetrate the skin, or even using toothpicks instead of needles) works as well or even better than real acupuncture. And one study found that acupuncture had a significantly greater benefits if the acupuncturists deliberately encouraged high expectations of a benefit in patients than if they were neutral about the likely effects. These findings suggest that psychological variables, such as the beliefs and expectations of patients and the behavior of those performing the acupuncture, are responsible for much of the perceived improvement in pain. These variables are often not specifically or effectively controlled in clinical trials, which would lead to variations in the apparent benefit of acupuncture unrelated to whether the treatment itself is actually doing anything to the body of the patient.

Of course, as I have argued in the past, such improvement in perceived pain is certainly real from the point of view of the patient, regardless of how it is generated. In many studies, the benefit is minimal and may or may not be clinically significant. It is almost certainly less than that achieved by properly tested pain medications which, when they are tested, rarely show the inconsistency in effects seen with acupuncture. Still , if a subjective experience like pain seems better to a patient, it cannot be said it isn’t better, only that it may not be due to any objectively measurable change in the patient’s body.

This, of course, also raises serious questions about whether the same benefits, if they exist at all, would be seen in veterinary patients receiving acupuncture. The only parties in the therapeutic interaction that have explicit beliefs and expectations are the owners and those performing the treatment, so it may be that they are the only ones to perceive a benefit. Without objective measures of response, such as force-plate measurements, activity monitors, and so on, it is dangerous to assume our pets truly feel less pain just because it looks to us like acupuncture is working on them.

The review also looked at side effects from acupuncture, something proponents of the therapy often argue are negligible or non-existent. They did find a number of serious adverse events, sometimes fatal or permanently disabling. The most common were pneumothorax (air getting into the chest through a hole made by an acupuncture needle and collapsing the lungs) and infections. These adverse events were not common, and they generally resulted from improper technique, so it is reasonable to argue that proper training and oversight of acupuncturists would prevent them. But of course if the therapy itself is nothing more than a placebo, it is difficult to argue that any life-threatening side effects are justifiable.

So the best we can say, after extensive research over decades, is that acupuncture might relieve pain for some patients with some conditions. Side effects are uncommon if it is properly performed but can be serious, even deadly, if not. The authors conclusions were these:

[N]umerous systematic reviews have generated little truly convincing evidence that acupuncture is effective in reducing pain. Serious adverse events continue to be reported.

Ernst, E. Soo Lee, Myeong. Choi, Tae-Young. Acupuncture: Does it alleviate pain and are there serious risks? A review of reviews. Pain. 2011;152:7555-764.

Posted in Acupuncture | 3 Comments

From SBM: How Popular Is Acupuncture?

Posted on March 25, 2011 by skeptvet

From Science-Based Medicine:

How popular is acupuncture?

One argument that often comes up when skeptics and proponents of so-called complementary and alternative medicine (CAM) debate is the question of the popularity of various CAM practices. Advocates of CAM often claim these practices are widely used and growing rapidly in popularity. Obviously, CAM proponents have an interest in characterizing their practices as widely accepted and utilized. Even though the popularity of an idea is not a reliable indication of whether or not it is true, most people are inclined to accept that if a lot of people believe in something there must be at least some truth to it. The evidence against this idea is overwhelming, but it is a deeply intuitive, intransigent notion that can only rarely be dislodged.

It might therefore be useful to get some idea of whether or not the claims of great popularity for CAM treatments are true. If they are not, fruitless debates about the probative value of such popularity could potentially be avoided, and it might be possible to diminish the allure associated with the belief that “everybody’s doing it.” 

Surveys of CAM Use

It is difficult to find good quality objective data on the popularity of particular CAM interventions, and many of the surveys that have been done are potentially misleading. For example,. the 2007 CDC National Health Interview Survey (NHIS) is widely cited as showing that about 30% of Americans use CAM therapies. A careful look at the details of this survey, however, shows that many of the supposed CAM therapies are really relaxation or exercise practices, such as massage and yoga, not medical therapies. Chiropractic is the only medical therapy generally classified as alternative that was used by more than 10% of people in the survey. And that was primarily for idiopathic lower back pain, an indication for which it is generally accepted, even by skeptics such as myself, as having some demonstrated benefit, about equal to standard medical interventions. These usage numbers haven’t changed in decades, which belies the notion that CAM is growing in popularity.

Similarly, much was made by the media of a recent CDC survey that supposedly showed widespread use of CAM therapies in hospice care facilities. A close analysis of this survey, also shows that most of the therapies listed are not truly alternative medical interventions and that fewer than half the facilities surveyed offered true CAM therapies, and fewer than 10% of patients in those facilities actually employed the CAM practices offered.

Studies of Acupuncture Use

I thought it might be useful to look at some of the data concerning the popularity acupuncture, since it is probably the most widely used and accepted CAM therapy after chiropractic, and there have been a few interesting studies in this area. There are certainly no comprehensive, high-quality data concerning how many people use acupuncture, for what indications, and with what sort of beliefs in its underlying theory or effectiveness. My purpose is not to make a definitive statement about how popular acupuncture is but simply to take a small step beyond vague impressions and unsupported claims about the popularity of this intervention and look at what research there is and what insight, if any, these numbers might give us. 

The 2007 NHIS data indicated 6.5% of Americans had reported ever using acupuncture. Of these, 22% had seen an acupuncturist in the last 12 months. 25% of those who had tried acupuncture had done so once, and 70% had seen an acupuncturist fewer than 5 times. The vast majority of those who had seen an acupuncturist had done so for some kind of pain, primarily arthritis and other orthopedic pain, headaches, or fibromyalgia. About 40% of the people who reported using acupuncture for a specific condition specifically reported not using conventional therapies for that condition, while 20-40% reported using some kind of conventional medical therapy for the same condition. 

It is often argued that lack of interest in the utilizing acupuncture is driven more by cultural prejudice or belief systems than by concerns about the evidence for its efficacy. There is likely some truth to the fact that people from different cultures prefer familiar styles of medical treatment, though of course this says nothing about what is actually safe or effective. And part of the appeal of acupuncture in the West is likely its exotic, “foreign” associations.

Some surveys of acupuncture use have looked at whether different ethnic groups in the West have differences in their utilization of acupuncture. Interestingly, one study from Canada found that while White and Chinese Canadians differed in their use of some CAM modalities, their overall use of CAM was the same, and their use of acupuncture specifically was about the same: roughly 8%. (Therapies included in definition of CAM in Quan et al 2008: Herbal remedies, massage therapy, chiropractic, acupuncture, amino acids, naturopathy, homeopathy, reiki, ayurvedic medicine, biofeedback, hypnosis.)

In contrast, a survey of Chinese Americans in a mental health services program found about 25% used acupuncture, and that this use was more prevalent among “less acculturated” individuals. This, of course, is a group not at all representative of the general population, so the relevance of this to overall acupuncture use among Chinese Americans and Americans of other ethnicities is not clear. Other studies have shown significant but complex relationships between ethnicity, education, and other variables and the likelihood of acupuncture use.

It seems reasonable that cultural traditions play some role in the acceptance or rejection of acupuncture as a medical therapy, but the current data do not support that cultural affiliation alone is the most important variable, and the reasons people use acupuncture seem quite consistent regardless of ethnicity or nationality. In any case, studies of populations in North America do not show anything approaching a majority of the population regularly using acupuncture as a medical therapy. Numbers vary from less than 10% to as high as 50% in some populations, but most tend to be in the lower end of that range.

Since acupuncture as it is currently understood and practiced in Europe and North America originated in China and has been employed there and in other Asian countries for a lot longer than it has been used in the West (though not nearly as long as is usually claimed), it makes sense that it would be far more widely used in that part of the world if it is truly as popular a therapy as its proponents claim.

One 2007 study in Taiwan found about 11% of beneficiaries of national health insurance had used acupuncture in a given year. Interestingly, while the survey found that overall use of Traditional Chinese Medicine (TCM) therapies was much higher than this (primarily due to use of herbal remedies), the use of TCM was still far behind the use of so-called “Western” medicine. TCM clinic visits accounted for only 9% of outpatient visits reimbursed under the national health insurance. This is similar to another study which found Chinese medicine (of all covered types) accounted for only 5% of the reimbursed care under the national health insurance system. The same study indicated that “Western” medicine was utilized more than Chinese medicine, especially among children, the elderly, and those with severe disease (consistent with the pattern of CAM use in the U.S., which is generally for self-limiting or chronic disease).

Yet another study in Taiwan specifically investigated acupuncture use and found about 6.2% of people covered by national health insurance utilized acupuncture in a given year, and over the seven years surveyed about 25% of covered individuals had received acupuncture treatment. As in the U.S., the vast majority of the acupuncture treatment sought was for musculoskeletal conditions or injuries (88%).

And a recently published series of surveys conducted in Japan found that about 5-7% of respondents used acupuncture in a given year, and that over a lifetime between 20-27% of respondents had at some time tried acupuncture. More than 80% of the use of acupuncture was for musculoskeletal complaints. About half of those who had used acupuncture indicated they would use it again, and about 37% indicated they would not.

The Bottom Line

So what does all of this mean? Well, probably not very much. Of course, differences in healthcare systems, insurance systems, study methods, and many other factors that are difficult to identify and asses, make direct comparisons between the use of specific CAM interventions in different countries very unreliable. I don’t believe the quality of the data generally allow very confident statements about the popularity of acupuncture or other specific CAM methods. However, proponents of acupuncture, and CAM generally often make such statements, trying to convey the impression that their approaches are growing rapidly in popularity and only perverse, closed-minded curmudgeons still resist them. The little evidence we have certainly does not support such claims. 

In the case of acupuncture, for example, the data show relatively low levels of utilization even in those countries generally regarded as having long historical traditions of using acupuncture. Informal investigations (e.g. 1, 2) have suggested that acupuncture and other CAM practices associated with China may not be as popular even in their native land as proponents in North America claim, and the formal studies I have discussed here seem to support that impression.

A large majority of people who seek acupuncture therapy, regardless of ethnicity or nationality, do so for treatment of musculoskeletal conditions and pain. There is good evidence that the therapeutic ritual of acupuncture has some symptomatic benefit for such indications. This is almost certainly a non-specific treatment effect (aka “placebo”). It does not seem to matter where needles are inserted or if they are inserted at all, and acupuncture therapy does not appear to measurably affect the course of any actual disease. (The Skeptic’s Dictionary has a clear and concise review).

The research data on acupuncture utilization suggests that from about 5-25% of people, regardless of nationality or ethnicity, will at some time try acupuncture for, mostly for some kind of musculoskeletal pain. Conventional therapies are often used along with acupuncture, and they are far more popular overall, especially for serious or acute conditions. So the little research there is suggests that acupuncture occupies a niche common to many CAM therapies. It is used at a low level by a small to moderate proportion of the population for conditions that are either mild, self-limiting, or without a definitive conventional treatment, and it is rarely used in lieu of conventional medical care. This is hardly a mounting wave of enthusiasm for acupuncture itself, much less the mystical theories and postmodern cognitive relativism often associated with it. 

So when proponents of acupuncture say it must work because it has been widely used for thousands of years in Asia and is growing rapidly in popularity in the West, rebutting the argumentum ad populum and argumentum ad antiquitatem fallacies may not be the skeptic’s only option. It may be worthwhile, and simpler, just to point out that acupuncture is neither as old nor as popular as is commonly supposed.

References

Chang LC. Huang N. Chou YJ. Lee CH. Kao FY. Huang YT. Utilization patterns of Chinese medicine and Western medicine under the National Health Insurance Program in Taiwan, a population-based study from 1997 to 2003. BMC Health Serv Res. 2008 Aug 9;8:170.

Chen FP. Chen TJ. Kung YY. Chen YC. Chou LF. Chen FJ. Hwang SJ. Use frequency of traditional Chinese medicine in Taiwan. BMC Health Serv Res. 2007 Feb 23;7:26.

Chen FP, Kung YY, Chen TJ, Hwang SJ. Demographics and patterns of acupuncture use in the Chinese population: the Taiwan experience. J Altern Complement Med. 2006 May;12(4):379-87.

Eisenberg DM. Kessler RC. Foster C. Norlock FE. Calkins DR. Delbanco TL. Unconventional medicine in the United States. Prevalence, costs, and patterns of use. N Engl J Med. 1993 Jan 28;328(4):246-52.

Ishizaki N. Yano T. Kawakita K. Public status and prevalence of acupuncture in Japan. eCAM 2010;7(4):493-500.

Quan H. Lai D. Johnson D. Verhoef M. Musto R. Complementary and alternative medicine use among Chinese and White Canadians. Can Fam Physician. 2008 Nov;54(11):1563-9.

Upchurch DM. Burke A. Dye C. Chyu L. Kusunoki Y. Greendale GA.A Sociobehavioral Model of Acupuncture Use, Patterns, and Satisfaction Among Women in the US, 2002Womens Health Issues. 2008; 18(1): 62–71. 

Posted in Acupuncture | 7 Comments

Veterinary Arthritis Treatments

Posted on March 24, 2011 by skeptvet

Over the couple of years of producing this blog, I have written about many different subjects. Some have come up repeatedly, and because they represent common and important issues, I thought it might be useful to collect related posts I’ve done into quick reference lists for some of these subjects. Maintaining an exhaustive and up-to-date list of resources on any one subject isn’t really feasible for a “spare time” project like this blog, but I will try to create and update some of these topic-based references as far as is practically possible.

SkeptVet Arthritis Treatment Reference List

Arthritis is a painful and potentially debilitating disease that commonly affects our animal companions. It is most often seen in older animals as a result of the normal wear and tear of living. However, certain congenital or developmental orthopedic abnormalities, such as hip dysplasia, as well as trauma, obesity, and other health problems, can create arthritis in younger pets as well. There are a number of well-supported conventional therapies for arthritis, including weight loss and non-steroidal anti-inflammatory drug therapy. There are also plausible and potentially useful treatments that have not yet been adequately studied, such as physical therapy and some supplements. And finally, there are implausible, unproven, and even demonstrably useless therapies, such as homeopathy and glucosamine. I have written about many of these therapies, and below are links to relevant articles along with brief summaries. I will try to update this reference list as I continue investigate and write about these and other arthritis therapies.

1. Acupuncture

The historical theories behind the use of acupuncture are unscientific and almost certainly false. And most of the marketing of acupuncture involves misleading and untrue claims about its historic origins and use. There is, however, very limited data concerning its use for arthritis in dogs and cats, and not much more for other conditions. What veterinary research there is is of poor quality and does not strongly suggest a benefit.

The research is much more extensive for humans and does suggest a subjective improvement in comfort when acupuncture is used to treat pain. However, the details of the research suggest this is almost certainly accomplished through psychological mechanisms and possible through very non-specific mechanisms. So while the benefit is small but real for some patients, it probably does not involve any actual change in the underlying disease. Whether such a “placebo” benefit would meaningfully help pets with arthritis is uncertain, but it does not seem likely.

Veterinary Acupuncture

Another acupuncture study shows it’s a placebo

The history of veterinary acupuncture: It’s not what you think

Electroacupuncture for intervertebral disk disease

2. Chiropractic

The theoretical foundations of chiropractic are vitalist pseudoscience and almost certainly false. There is no evidence that the “vertebral subluxation” chiropractors often claim to treat exists at all, and even many chiropractic professional organizations are beginning to distance themselves from this historical concept. There is virtually no controlled scientific research on the subject of chiropractic for arthritis in pets, though it is commonly recommended by chiropractors and some veterinarians. The research in humans shows some likely benefit for uncomplicated lower back pain, essentially equivalent to standard therapies such as physical therapy, stretching and exercise, massage, and non-steroidal anti-inflammatory medications. The evidence does not support the use of chiropractic for any other conditions.

Veterinary Chiropractic

The end of chiropractic? Of course not!

Chiropractic: the more we look the less we find

3. Homeopathy

The theoretical foundations of homeopathy are completely incompatible with well-established scientific understanding of physics, chemistry, and biology. The extensive research in humans shows no convincing evidence of any benefit for any condition beyond placebo effects. The research in animals is sparse and of poor quality and does not support the use of homeopathic remedies in the treatment of arthritis.

Veterinary Homeopathy

Homeopathy works for arthritis: Or maybe not

4. Glucosamine and Chondroitin

Glucosamine and chondroitin are chemicals found naturally in joints and cartilage. There was once good reason based on sound scientific reasoning and in vitro studies to think that oral supplementation of these chemicals would be useful in the prevention or treatment of arthritis. However, the research in companion animals, which is quite limited and of variable quality, has not shown convincing evidence that this is actually true in the real world. And the extensive research in thousands of humans over decades pretty clearly shows that these products have no benefit beyond placebo. They are almost certainly safe, and very likely useless for most pets.

Veterinary Glucosamine and Chondroitin

Growing skepticism about glucosamine for arthritis in dogs and cats

Is recommending glucosamine for arthritis evidence based medicine or wishful thinking?

Nope, glucosamine and chondroitin still don’t work in humans

Cognitive dissonance in action: Glucosamine no matter what!

LEGS Glucosamine Study-Little evidence of meaningful benefit

5. Fish Oil

Essential fatty acids from fish, including EPA and DHA, have many potential benefits based on sound theoretical and in vitro work showing their potential to reduce inflammation. There have been very few studies in companion animals on their usefulness for arthritis, and these do not seem to show much if any benefit, though the work is preliminary. The research in humans is also variable in quality and in results. Fish oils are very likely safe for most pets, and they may or may not have any beneficial effects on arthritis, but the data so far is not encouraging.

Two studies of fish oil for canine arthritis

Another study of fish oil for canine arthritis

5. Electromagnetic Therapy (PEMF)

Various devices that expose arthritis joints to electromagnetic fields as a treatment for arthritis are available and in use for humans and animals. There is some in vitro evidence that electrical fields certainly have effects on living cells, but this says nothing about exactly what these effects are and if they are helpful, harmful, or insignificant in living animals. Much of the marketing of these devices uses misleading pseudoscientific language to talk about mystical vitalist notions of “energy” as if they were established scientific principles. There is so far no reliable scientific research on the use of these devices for treatment of arthritis in dogs and cats. The limited research in humans is variable in quality and results and is so far inconclusive.

PEMF devices for pets

6. Cold Laser Therapy

Non-cutting laser therapy is widely used by chiropractors and some other CAM practitioners to treat pain and many other conditions. While laser light does have measurable effects on cells in vitro, this says nothing about potential clinical uses of laser light. Much of the marketing of these devices uses misleading pseudoscientific language to talk about mystical vitalist notions of “energy” as if they were established scientific principles. There is so far no reliable scientific research on the use of these devices for treatment of arthritis in dogs and cats. The limited research in humans is variable in quality and results and is overall very weak.

Cold laser therapy

7. Stem Cell Therapy

One of the hottest, most fashionable new therapies for a wide range of ailments is autologous stem cell therapy, in which fat is taken out of an animal, stem cells are extracted from it, and then these cells are injected back into the patient. There is extensive theoretical and laboratory work in animals and humans to indicate a variety of effects of these cells, and there is good reason to believe that clinical benefits may be possible. Unfortunately, there is no agreement about what these cells do in living animals and how they do it, and there is very little clinical research evidence to support any one of the many different commercial stem cell therapies marketed for arthritis in dogs and cats. Leading researching in human and veterinary stem cell therapies caution that our knowledge about these cells and what they do is too preliminary to justify claims that they are safe or effective in real patients. I am hopeful that safe and effective stem cell therapies will one day be available, but so far none have proven themselves and using them is still a gamble.

Veterinary stem cell research: Is this the best we can do?

Vet Stem’s stem cell therapy and Chemaphor’s Oximunol join forces

Selling veterinary stem cell therapies: Medivet’s dodgy advertising

Stem cell therapy: Still an uncontrolled experiment on our pets

Veterinary stem cell therapies discussed at Fully Vetted blog

8. Non-steroidal anti-inflammatory drugs (NSAIDs)

There is a huge group of NSAIDs license for treatment of arthritis in dogs, and the evidence from the theoretical and in vitro level through multiple clinical studies is unequivocal that they have a significant positive effect on arthritis. There is no doubt that they have potential side effects, as all effective medicines due. But these are mostly well-understood, and with proper use of the medicines and proper monitoring of the patient the risks are far less than the benefits, or than the propaganda of alternative medicine proponents often suggests.

Safety and efficacy of NSAIDs for canine arthritis

A new tool for evaluating the effects of arthritis treatments in dogs

9. Prolotherapy

Prolotherapy is a purported treatment for connective tissue and joint pain and disability. It involves injecting substances which induce inflammation and other chemical and cellular reactions into affected tissues. These reactions are theorized to relieve pain and improve function. The logic of this theory is questionable, and no clear mechanism for beneficial effects from prolotherapy has been described, but it is possible that the theory could be valid.

The clinical research on prolotherapy in humans is generally of low quality and results have been mixed. There is great variation in the techniques used by different investigators, so it is difficult to compare or generalize between studies.

There is virtually no controlled research investigating prolotherapy in companion animals, and all claims made for safety and efficacy in these species are based solely on anecdotal evidence.

The use of proltherapy in pets should be viewed as experimental with unknown risks and benefits. Such treatments should be reserved for patients that have significant symptoms that have failed to respond or cannot be treated by conventional means.

Prolotherapy for Dogs and Cats

10. Autologous Platelet Therapy

Encouraging Study of Platelet Therapy for Arthritis in Dogs

11. Other Supplements

Duralactin for Arthritis

12. Other Reviews

American Academy of Orthopaedic Surgeons Review of Arthritis Treatments

Posted in Topic-Based Summaries | 57 Comments