Special Challenges of Science-Based Veterinary Medicine

Posted on July 29, 2010 by skeptvet

The following is a post I contributed to the Science-Based Medicine blog.

On this site there have been several thoughtful posts (e.g. by Dr. Atwood and by Dr. Novella), and subsequently much heated commentary, on the distinction between Evidence-Based Medicine (EBM) and Science-Based Medicine (SBM). I agree wholeheartedly with the position that the two are not mutually exclusive, and that SBM is essentially EBM as it should be practiced, with a comprehensive consideration of all relevant evidence, including the subject of plausibility. As a practicing veterinarian, and an officer of the Evidence-Based Veterinary Medicine Association (EBVMA), I am keenly interested in bringing to my profession a greater reliance on high quality research evidence and sound scientific judgment, and reducing the reliance on individual practitioner intuition and experience in making clinical decisions. However, those of us in veterinary medicine face some special challenges which make the subtle but important distinction between EBM and SBM especially salient. 

Where’s the Evidence?

The first of these challenges is the paucity of high quality clinical research evidence. As an example, in his 2007 book Snake Oil Science, R. Barker Bausell examined the research evidence concerning the use of glucosamine as a treatment for osteoarthritis in humans. He was able to analyze the strengths and weaknesses of a Cochrane Review which included 20 studies with 2570 patients (the most recent revision of this review includes 25 studies with 4963 patients), a NEJM study with 1583 patients, and an Annals of Internal Medicine study with 222 patients treated for two years. His conclusion was that the intervention was not more effective than placebo.

I recently did a targeted search of the PubMed literature database for a brief evidence-based medicine feature on the subject of glucosamine and chondroitin as treatment for osteoarthritis in dogs, currently in press at the Journal of the American Veterinary Medical Association. A search of the terms “glucosamine,” “arthritis,” and “dog” yielded eight references, of which three were relevant (a more comprehensive search strategy yielded sixteen references, but only the same three were relevant to the clinical question). The three useful references included two clinical trials involving a total of 113 dogs and each lasting about 2 months, and a systematic review of treatments for canine osteoarthritis which evaluated one of these two clinical studies. Predictably, the larger, better designed trial with objective measurement criteria showed no benefit of glucosamine, while the smaller, less well-controlled trial with only subjective criteria and a 23% dropout rate in the glucosamine group showed some benefit at some assessment points.

Where’s the Money?

Glucosamine is an extremely popular, and profitable, supplement routinely recommended by veterinarians and administered by owners to their geriatric dogs. Yet the clinical trial evidence concerning its effects is nearly non-existent. The depth of the evidence is no better for many, many routine clinical interventions in veterinary medicine. The primary reason for this is simple: money. 

Obviously, the health of companion animals is not as high a societal priority as human health. Many countries have little or no formal companion animal medicine at all, of course, much less high quality, evidence-based pet medicine. And even in the developed world, the absolute size of the veterinary medical profession and associated industries is dwarfed by that of the human medical industry. 

In the United States, surveys show that most dog and cat owners have come to consider their pets to be members of their family, and their willingness to pay for veterinary care has increased along with this shift in attitude. The same appears to be the case in Europe and other developed nations. This has allowed the quality and technological sophistication of veterinary care to increase. 

Pharmaceutical companies have followed this trend, increasing their financial investment in their own internal research activities, as well as funding the lion’s share of companion animal health research generally (with all the ethical and practical problems that creates). Pfizer, the largest fish in the “Big Pharma” pond, claims to spend $300 million annually on veterinary research globally, for both companion and agricultural animals. However, the company is expected to spend $9-$9.6 billion this year on its human research and development. The same pattern is true of government research spending. Veterinary medicine will always be the poor stepchild of medicine, and we cannot expect to have anything close to the quantity or quality of research evidence available to MDs trying to practice evidence-based medicine. 

A Pack of Lone Wolves?

Another barrier to effective utilization of research evidence in veterinary medicine may be demographic and cultural. In the United States, the average veterinary practice has fewer than three veterinarians, and between one-third and one-half of veterinarians are self-employed practice owners. And most companion animal veterinarians are general practitioners, only about 10-15% of practicing vets being board-certified, with the extended academic training and, hopefully, greater awareness of and respect for research evidence that might be expected to come from this training.

As a profession, we veterinarians tend to be entrepreneurial, self-reliant, and independent. This contributes to a reluctance to let anyone tell us what to do, which may be how veterinarians perceive the position of evidence-based medicine. There is no solid data on the subject (though I am involved in a survey study which will hopefully provide some soon), but in discussions with colleagues I have sensed a great deal of anxiety about the notion of “cookbook medicine” which disdains the hard-won wisdom and experience of the individual clinician. Veterinarians are reluctant to accept the idea that there may be broadly applicable standards of care they ought to adhere to, even if their personal judgment conflicts with the evidence for these.

Undoubtedly, our colleagues in human medicine share a similar temperament and similar sorts of anxieties about “cookbook medicine”. However, these may be tempered to some extent by more widespread advanced training, more structured and supervised practice environments, and greater assessment and monitoring of outcomes, which may partially explain the greater acceptance of EBM in the human medical profession. And though the case of Dr. Rolando Arafiles, Jr. illustrates the weaknesses in the systems for monitoring physician behavior, I think it is clear that the influence of government regulation, and the threat of litigation, give the concept of adhering to a recognized medical standard of care far greater teeth in the field of human medicine than it has in veterinary medicine.

SBM, EBM, or OBM?

So how does this relate to the difference between SBM and EBM? Well, traditionally the scarcity of clinical trial evidence has led veterinarians to practice primarily opinion-based medicine. Personal experience and intuition and the opinions of individual experts or mentors are the predominant foundations for clinical decision-making. There is little or no outcome assessment, so veterinarians must rely on their own clinical experience to judge whether their practices are effective. 

The negative consequences of these strategies are many. There is dramatic inconsistency in the diagnosis and treatment of even common diseases. I routinely have to explain to my clients that if they ask ten vets a question, they are likely to get seven or eight different answers. You can imagine how frustrating this is for them, and how little confidence it inspires in our expertise.

OBM Leads Kids to the Hard Stuff, FBM!

As most readers of this blog likely already know, there are many reasons why individual judgment is an unreliable guide to the true efficacy of a medical intervention, and why we should be reticent to entirely trust our own intuitions and experience. But opinion-based medicine is also a “gateway drug” to faith-based medicine, otherwise known as complementary or alternative medicine. If you are accustomed to judging the safety and efficacy of interventions on the basis of the cases you have seen personally or the opinions of “experts,” you are more likely to be persuaded by the individual experiences of clinicians promoting and alternative practice, and more likely to think that giving it a try yourself is the most reliable way to know if it really works or not. 

The Internet abounds with holistic veterinarians who claim they started their careers as scientific, skeptical doctors but that their frustration with the limitations of mainstream medicine and the problems they could not solve led them to experiment with, and ultimately become promoters of, faith-based miracle therapies of every kind that share no theoretical or practical features in common other than being validated primarily by testimonial and not consistent with scientific knowledge or evidence. 

Tooth Fairy Science exists in veterinary medicine, but it is less of a problem than the simple lack of research evidence and the consequent reliance on even less trustworthy forms of evidence. So veterinary medicine needs a science-based approach even more desperately than human medicine because we have so little clinical trial evidence to rely on, and so few resources to generate more and better evidence. The tragedy of money and talent wasted on studying therapies that have vitalist theoretical foundations inconsistent with established scientific knowledge is even more poignant in the relatively impoverished world of companion animal medical research. Plausibility must play an important role in deciding how we allocate the scarce resources we have in order to maximize the useful information we can generate, and the subsequent clinical benefits for our patients.

Towards a One Health Approach

Veterinarians must also take advantage of the evidence that our colleagues in human medicine have generated for us. There are serious dangers in extrapolating research evidence across species, of course, but we cannot afford to entirely ignore the wealth of human medical research that is relevant to our patients. Examined cautiously and judiciously, this data can help us target our own research efforts more efficiently. Just as animal models have an important role, despite their limitations, in human health research, so human clinical research can inform veterinary medicine. As clinicians, we can make more science-based decisions, even when relevant veterinary research is lacking, if we are aware of the research in humans that already exists on the conditions and interventions we are considering. 

If glucosamine is shown to be no more than a placebo after years of research in thousands of people, how much money and effort should we invest in studying its effects in dogs? And how strongly should we promote it to our clients, the vast majority of whom must pay for their pet’s care out of pocket, without insurance coverage, and who commonly must eschew needed care or even euthanize their companions for want of money to pay medical costs?

A Worthy Goal

There has been a steady growth in the quality and sophistication of care available to companion animals in the last several decades, and I am hopeful that this will continue. But I believe the interests of our patients and clients will be best served if the care we provide is as soundly science-based as possible. And while I think evidence-based medicine can become the standard in the veterinary field, with beneficial effects on the quality of the care we provide, we need the additional features of the science-based medicine approach even more than our MD colleagues: a respect for the importance of plausibility in allocating research resources and an understanding of the need to integrate all relevant evidence when making clinical decisions about interventions in the face of a scarcity of high quality clinical trial research. 

Despite all the histrionic accusations of some alternative medicine advocates about mainstream veterinarians being tools of the pharmaceutical industry or reluctant to accept unconventional approaches only out of closed-minded prejudice or a fear for our income, the reality is that we care deeply for our patients and want to provide them with the best care we can. I truly believe, and I hope the profession as a whole will come to accept, that science-based medicine is far more likely to help us do so than the opinion-based medicine we have traditionally relied on.

Posted in General, Science-Based Veterinary Medicine | 21 Comments

Double Helix Water: More Magic Water Quackery

Posted on July 20, 2010 by skeptvet

The beauty of pseudoscience as a marketing tool is that it is, for those not trained in the particular branch of real science being mimicked, almost indistinguishable from the real thing. Of course, many of the warning signs of quackery are often present, especially claims of revolutions or “paradigm shifts” that overturn well-established science, claims of a single cause or cure for many unrelated diseases, the presence of the Quack Miranda Warning, and naturally lots of testimonials with a conspicuous absence of real evidence published in legitimate scientific journals. But it is easy to see why the use (misuse, really) of scientific terminology, often by people with legitimate (though irrelevant) scientific degrees, can be quite convincing even if the idea or product being marketed is completely bogus.

Our latest example has all this and much, much more! Meet the revolution in veterinary medicine that is Double Helix Water! What is Double Helix Water? Here’s what the “inventors” and promoters of this product say:

Double Helix Water™ is solely ultra-pure H2O but we believe it is H2O in a hitherto undiscovered fundamental “phase”; not liquid, ice or vapor “phase” but a molecular solid phase even at room temperatures.…this “phase” may be the key to many of the body’s inherent healing properties thus explaining many of the mysteries of alternative health practices. They demonstrate through rigorous scientific experimentation that water can form a solid particle at room temperature. The discovery of this particle then, begins to unravel the mystery behind the differences between allopathic and homeopathic medicine as we know it.

Ahhh, so there is a connection with homeopathy, eh? Well, sort of. the promoters certainly claim their “discovery” explains the powerful effects of homeopathy (which they seem to take as a given, despite the strong, consistent evidence that homeopathy is no better than a placebo). However, there is no talk of the Law of Similars, Dilution and Sucussion, which are core theoretical concepts behind orthodox homeopathy, so one wonders exactly what the connection is beyond the absence of anything but water in this product and in homeopathic remedies. Despite this, the forward to the promoters’ book on their product states clearly that the “discovery” takes,

the concept of homeopathy into the twenty-first century…Their demonstration of microscopic clusters in water is groundbreaking and revolutionary! Their purification of water, with the atmospheric purity described, places homeopathy on a scientifically valid foundation that is equal at least to the discovery of atomic energy.

What Are the Claims?

On another site devoted to this product, the promoters first weasel out of any liability or fraud allegations by stating,

It is not a drug or a curative agent (medicine) in any respect. [We] are not medical doctors and we want all to know that we make no representations that this water treats or cures anything, period….let’s all be careful about how we introduce this discovery to the world: Do not make claims, please! This water does not “cure” cancer, does not “cure” diabetes—it does not cure anything. It is not a drug; it is not a medicine. It is simply water…

Disclaimer out of the way, they then merrily go on to say

It is our belief that this phase of water is a central agent in the arsenal of the body’s immune response….we theorize that these particles are the molecular basis for what Chinese Medicine has suggested for over two thousand years: that an electrical matrix surrounds the body and this electrical matrix is the senior dominating factor in all health issues….Therefore it is very feasible that we have found a material basis for the Chinese meridians.

Wait, I thought their “discovery” proved the scientific basis of homeopathy. So, it also proves the scientific basis behind Traditional Chinese Medicine? Wow! Anyway, on to more medical claims:

….have numerous MDs and scores of other healthcare professionals recommended this new phase of water to their clients, patients and family members for a healthy lifestyle? Absolutely. If one is a rational, sane individual and witnesses large numbers of people with many varied health problems experiencing remarkable changes in their wellness, something occurs deep inside oneself. It becomes more a crusade than a research line. And the people whose lives have been saved or changed greatly for the better want others to know what they think of this water—so the word spreads.

And not to leave out the important (and potentially lucrative?) veterinary sector, the promoters of Double Helix Water provide some additional endorsement on this site from a paragon of the holistic hodgepodge school of veterinary medicine, Dr. Deva Khalsa, who says:

I have found Double Helix to be a cutting edge product that works deeply to heal my canine and feline patients. I’ve found it helpful in cases of arthritis, autoimmune disease, cancer and diabetes along with other medical problems.

The folks marketing Double Helix Water, clearly have a philosophical agenda that goes beyond their claims of mere scientific interest in the nature of water, or even the possibly genuine belief that anecdotes and testimonials have really shown it to be useful. This is clear from the preface to their book, which contains a remarkable number of quack warning signs efficiently packaged in a small space:

 The Secret of Life has been the foundation of philosophy and medicine throughout history. The Chinese called it chi; the Japanese, qi; the Indians, prana; and Wilhelm Reich, orgone. Much of medicine before 1940 was rather pragmatic empirical practice with many errors. Since 1940 the bulk of modern medicine has been a takeover by the PharmacoMafia—my title for the pharmaceutical industry. Today Modern Medicine is at least the third leading cause of death in the United States (JAMA, July 2000). Drugs that have little justification and serious risks, called side effects, are added almost daily to the stream of offerings. Numerous brave souls question the current system, and yet it is THE SYSTEM rejecting and attacking viciously virtually every alternative.

Nothing as inspiring as an open-minded individual disinterestedly pursuing the greater good of all, eh? Well, perhaps not entirely open-minded philosophically, as this passage illustrates. What about disinterested? Well, let’s not forget that even though it’s “just water,” they aren’t exactly giving it away. Here’s the “bottom line” from one of their two official vendors, Dr. Khalsa:

One bottle of Double Helix Water™ (a three months supply) at an average usage price of $1.22 a day – $109.95

One bottle of Double Helix Water™ (a two months supply) at an average usage price of $1.33 a day – $79.99

Special Subscription Pricing Offer – Receive a three month supply every three months at an average usage price of $1.12 a day – $99.99

Who’s Behind It?

Interestingly, two of the promoters, David Gann and Dr. Shiu-Yin Lo appear to have a long history of selling dubious forms of magic water. Dr. Lo was Director of Research and Development for American Technologies Group (ATG) in the 1990s. He claimed to have discovered another form of structured water with elements called “IE crystals” in it, which was marketed in the form of a detergent-free cleaning product called a “laundry ball” and also an automobile engine performance enhancer called The Force. According to one source, these products were investigated by the Oregon Department of Justice and determined to be fraudulent, and the company paid a fine and eventually closed down. Affidavits from a an independent analytical laboratory and a professor of chemistry at the University of Oregon were submitted refuting the company’s claims about IE crystals, and the DOJ concluded that these claims were not supported and not consistent with appropriate scientific practices. David Gann was the Director of Marketing for ATG.

Dr. Norm Shealy, who wrote the preface to the marketing book about Double Helix Water, is a committed proponent of Hodgepodge Holism on the human side, including spiritual and prayer healing, hormones and all manner of supplements, energy medicine, and a wide variety of unproven and quack therapies. All three of these individuals obviously have lifelong personal, and financial, commitments to bogus medical therapies.

And there is the veterinary face of Double Helix Water, Dr. Deva Khalsa. From her web site, she subscribes to any and all forms of alternative therapy grouped, for no obvious reason, under the label “holistic.” Acupuncture, homeopathy, herbal therapies, chiropractic, applied kinesiology, prolotherapy, energy medicine, hair analysis, all sorts of supplements, and of course Double Helix Water. Dr. Khalsa will even consult and prescribe these remedies by phone, which is certainly a more convenient way of assessing your pet’s needs than a bothersome in-person visit or physical exam.

What About the Science?

So, what about this “scientific breakthrough”? Any chance it’s real? Well, not being an expert in physics or chemistry, despite some training in those fields, I can’t evaluate the underlying theory very extensively. Of course, neither can the doctors who believe in the remedy, despite their glowing testimonials and deep faith. Those of us who practice science-based medicine are sometimes at a disadvantage since we cannot as blithely dismiss the claims we haven’t investigated or understood thoroughly as easily as those who practice faith-based medicine can affirm them without investigating or understanding them. However, there are some with the appropriate expertise who do dismiss the claims about “structured water” in general, including a product previously “invented” and sold by one of the promoters of Double Helix water. Apart from the affidavits and analyses submitted in association with the fraud investigation of ATG, there is an entire web site devoted to structured water quackery, provided by a former professor of chemistry, Stephen Lower.  Apparently, there is an entire industry built around claims that manipulating the atomic or molecular properties of water can solve all your health problems. Dr. Lower mentions Dr. Lo’s claims about IE crystals and points out that the only scientific publication concerning these claims was in a journal, Physics Letters B, that does not require reporting the details of one’s methodology and has minimal peer review, so it is difficult to assess the quality or reliability of the data presented. The findings have been challenged on practical and theoretical bases both by Dr. Paul Engelking, the author of the affidavit in the ATG case (here) and by Steven Bittenson, a physicist who is actually a proponent of homeopathy (here). Another paper of Dr. Lo’s, on so-called “stable water clusters” and presented on the front page of the Double Helix Water website (here) is from the companion journal Physics Letters A. No other journal appears willing to publish Dr. Lo’s claims about water, which should be cause for some skepticism about them.

Dr. Lower provides lengthy discussions on his site of the science, and pseudoscience, behind “structured water,” and while my expertise only permits me to say with confidence that the medical claims for Double Helix Water are implausible and without any real evidence to support them, Dr. Lower cogently argues that the same is true of the underlying physics and chemistry claims made by the inventors of this wonder product.

So in essence we have a group of individuals dedicated not only to theories and practices which are improbable and not supported by solid evidence or accepted by mainstream science, but also with a long history of trying to make a living selling products based on these theories. The perfect storm of cognitive dissonance, philosophical bias, and financial self-interest to prevent any rational consideration on the part of the promoters that they might be mistaken. The result is yet another unproven and most likely thoroughly useless product sold to people who only want the best for their sick pets, and most often to those whose animal companions have serious medical problems for which highly effective real therapies don’t exist. Empty promises and false hope, for only $79.99-199.99 per bottle (plus shipping and handling).

Posted in Miscellaneous CAVM | 145 Comments

Supraglan: Empty Promises, Not Medicine

Posted on July 14, 2010 by skeptvet

I came across an especially egregious example of veterinary quackery recently which I wanted to warn people about. Petwellbeing.com, a subsidiary of the Canadian company Natural Wellbeing Distribution sells a product call Supraglan, which it advertises as a treatment for Cushing’s disease (hyperadrenocorticism). Cushing’s disease is a serious, chronic disease in which the body produces excessive steroid hormones, which have a variety of deleterious effects on many different body systems. It is usually caused by a benign tumor in the pituitary gland in the brain, which tells the adrenal glands to make too much of their normal steroid products. Some cases are caused by a tumor of the adrenal glands, which is almost always an aggressive, highly malignant cancer. The symptoms of Cushing’s disease can be created by chronic use of steroids given to treat other diseases, but this is a different condition in that if the patient stops getting the drugs then the symptoms will resolve.

The PetWellbeing website offers a brief, and inaccurate, description of the disease and then claims their product:

is gentle yet effective, safe for long-term use without adverse side effects…Supraglan is designed to restore your pet’s quality lifestyle and to increase life expectancy by reducing thirst and regulating elimination (liver/kidney and digestive); balancing blood sugar levels (endocrine); increasing muscle use and ability (anti-inflammatory); protecting against infection (immune); and by promoting a healthy skin and coat (natural herbs)

Of course, to cover their behinds legally, the company includes the Quack Miranda Warning on their page acknowledging that the FDA has not approved the product for what they are selling it for, but this is intended to apply only to products that are making so-called “structure and function” claims, meaningless and unscientific statements that the product “supports” some body system, not that it treats or prevents an actual disease. So the treatment claims are illegal to begin with since the drug is not FDA approved as a treatment for Cushing’s disease.

Unfortunately, even the minimal restraint showed by the actual manufacturer is not found on other web sites promoting this snake oil. One site states, “There are many similarities between the symptoms of Cushing’s Disease and Addison’s Disease in dogs–both considered fatal in canines. There are many rumors in regard to the miraculous healing of the natural supplement Supraglan, reported to cure both diseases.” Addison’s disease is a lack of adrenal steroid hormones produces by destruction of the adrenal glands. It is, essentially, the opposite of Cushing’s disease, and yet Supraglan is reported to cure both! How does it accomplish this miracle? Apparently, it uses, “natural ingredients to decrease the adrenal system in dogs from a completely hyperactive state, the product slows the overproduction of the corticosteroid hormones which have become overloaded in the dog’s system.  Side effects have not been seen yet in the usage of Supraglan.”

So a natural, side-effect free cure for Cushing’s disease and it’s opposite. See any warning signs of quackery yet? So what’s in this miracle elixir?

  • Borage: contains natural precursors of adrenal glands hormones; supports endocrine system functions; helps with detoxification; supports adrenal cortex.   
  • Astragalus: tonic; nutritive; supports liver function; helps maintain immune system.
  • Bistorte: astringent, soothing, anti-inflammatory, has a tonic effect on liver and kidneys.
  • Eleutherococus Senticosus: helps maintain normal hormonal actions (ACTH and cortisone) on adrenal glands; supports the immune system.
  • Wild Yam: natural inflammation management; contains steroidal saponins (dioscin, dioscorin) used as sources of saponins in the preparation of steroid hormones.
  • Licorice: adrenal supporting (contains glycyrrhizin, a compound similar to corticosteroids); immune support; anti-inflammatory.
  • Dandelion: highly nutritious food; supports liver function, digestion and appetite.

Ok, now here’s the tough part. What’s the evidence to support these dramatic claims? You guessed it–reams of testimonials from “satisfied customers” and not one single research study of any kind. Some of the claims for the specific ingredients are found in reference guides to herbal therapy, usually based only on tradition or limited suggestive in vitro or lab animal studies. A search of the usual source, including Pubmed, Cochrane Reviews, even the National Center for Complementary and Alternative Medicine, which is quite friendly to herbal medicine in general, turned up not a single study that lent any support at all to the idea that these ingredients, individually or in combination, are a safe and effective treatment for Cushing’s disease.

I did find a few studies suggesting why some of the ingredients might be a bad idea to use in these patients. Licorice is known to cause pseudohyperaldosteronism, a hormonal imbalance which messes up the levels of sodium in the blood and can cause high blood pressure and even interfere with proper diagnosis of adrenal disease. Wild yams have been thought to increase some steroid hormones, and so have been used as a treatment for menopausal symptoms, but in reality it does not actually increase steroids, and its apparent effects on symptoms was likely due to adulteration of commercial yam products with synthetic hormones

There probably are some in vitro or lab animal studies, maybe even a small human clinical trial or two, that might have some suggestion of some potential effects on the adrenal hormone system. After all, herbs are essentially drugs, though usually unpurified and inadequately standardized and tested, so they likely do have some effect. I would be interested in any such studies any of you are aware of, but I can promise you there is nothing that would justify selling pet owners whose dogs have a serious, life-threatening disease, this concoction with claims that it will cure them or even meaningfully improve their quality of life. Testimonials, tradition, and blind guesswork based on in vitro studies are not sufficient to make such claims or profit from people with sick animal companions.

I expect I will now receive the usual angry comments of the following sort:  “Who do you think you are?! I used it and my dog got better so you’re stupid! You’ve just been bought by Big Pharma to push their toxic drugs!” I have received such comments following previous posts on similar nostrums such as Neoplasene, Yunan-Paiyao, and so on. I don’t expect to be able to head these off, but I will try to save myself some time later and make a few points:

1. For reasons discussed at length here and anywhere critical thinking is respected, anecdotes are not proof, only suggestions of areas to study more formally. A million people are capable of being wrong as easily as one, so if you believe my assessment of this product is incorrect, show me real evidence, not testimonials. The hierarchy of evidence is the best guide to what is real evidence and what isn’t, if there is any doubt.

2. I make my living practicing medicine, and that includes treating Cushing’s disease. This has nothing to do with my objections to this product. If there were proof it worked, I would use it just like I use conventional treatments now. And don’t forget the folks making and selling this have a financial incentive to promote its use the lack of evidence it works that is far greater than any incentive I have to discourage its use. I am motivated by a belief that evidence and the truth serve my patients and clients better than false hope and misleading marketing.

3. I am not closed-minded, dogmatic, and I am happy to change my mind if the evidence warrants it. Being skeptical doesn’t mean disbelieving things automatically. It means withholding judgment until the facts are in. There are almost no facts to base a judgment on here, so the burden of proof is on those making wild claims (and a profit) on the product, not on those of us pointing out there is no good reason to think it works.

Posted in Herbs and Supplements | 164 Comments

The History of Veterinary Acupuncture: It’s Not What You Think

Posted on July 11, 2010 by skeptvet

One of the most common arguments made in support of using acupuncture on animals is that veterinary acupuncture is an ancient art practiced and refined in China for thousands of years. On one website providing referrals for acupuncturists, the claim is made that,

Acupuncture has been used on animals for over 4000 years. Legend has it that veterinary acupuncture was discovered when lame horses used in battle were found to become sound after being hit by arrows at distinct points. In any event, there is evidence that Chinese “horse priests”, the caretakers of the army’s horses, practiced acupuncture during the Zang and Chow Dynasties around 2000-3000 BC.

Similarly, the International Veterinary Acupuncture Society (IVAS) website claims,

Acupuncture may be defined as the insertion of needles into specific points on the body to cause a desired healing effect. This technique has been used in veterinary practice in China for at least 3000 years to treat many ailments. The Chinese also use acupuncture as preventive medicine against such problems as founder and colic in horse.

Of course, the notion that the length of time a methods has been in use is somehow proof of its safety or efficacy is fundamentally unsound. Unsafe and ineffective treatments (bloodletting, various forms of burning or “cauterization,” faith healing and, I would argue, acupuncture) often endure for centuries, even millennia despite having no benefits and even being harmful, due to the many, many reasons people are prone to making inaccurate judgments about such things. Even if acupuncture has endured for thousands of years, it has failed in all that time to extend our life expectancy, reduce infant and childbirth mortality, eliminate any infectious disease, or accomplish any of the other dramatic improvements in human and animal health scientific medicine has given us in the last 200 years.

Still, it is understandable why people might find the tenacity of a method to be a strong argument for it being effective. Unfortunately, in the case of veterinary acupuncture, the appeal to longevity argument is not only misleading, it doesn’t happen to even be true!

A recent article in the German science history journal Sudhoffs Archiv makes a strong and detailed case that most of the sources cited to support the argument that the Chinese have practiced acupuncture on animals for thousands of years are actually describing bloodletting and cauterization practices that have no meaningful relationship to what is considered to be acupuncture today. The authors also argue that many of the veterinary techniques these Chinese sources describe using on horses correspond closely to techniques found at the same time or even earlier in Greek, Egyptian, Arabic, and Indian sources, and that they may have derived originally from Western practices or had common sources. The article’s authors include two professors of East Asian history and an equine veterinarian, Dr. David Ramey, who has written extensively on equine medicine in generally and on complementary and alternative veterinary medicine.

Buell PD, May T, Ramey D. Greek and Chinese Horse Medicine: Déjà vu All Over Again. Sudhoffs Archiv. 94(1);2010:31.

According to the authors, the earliest written records of Chinese veterinary medicine, from the 3rd century BC, concern primarily herbal treatments. By the 6th century recommendations concerning bleeding and cauterization are found, though herbal therapies are still the primary treatments recommended for animals. The earliest surviving Chinese text specifically devoted to veterinary medicine dates from 1384, though much of the material it contains appears to have originated in the 11th and 12th centuries. none of these early texts refer to anything that could be considered acupuncture in the modern sense. The IVAS defines acupuncture as, “the insertion of needles into specific points on the body to cause a desired healing effect.” Though there are a variety of techniques, including using heat, laser light, and electricity on supposed acupuncture points, most commonly veterinary acupuncture takes the form described by the Australian Veterinary Acupuncture Group: “Acupuncture is the technique of using very fine needles that pierce the skin at specific points in order to treat or prevent disease.”

There is no evidence for such techniques in the early Chinese veterinary texts. Though the term “zhen” used in such texts is often incorrectly translated as “acupuncture,” it is clear from a thorough reading of these texts that the term was used to refer to bleeding, cauterization, and even surgical interventions, not acupuncture as applied to people and animals today. Such interventions become more prominent in later Chinese veterinary texts, however these texts also do not describe anything that can be reasonably called acupuncture. Methods resembling modern veterinary acupuncture apparently were not widely practiced in China until the 1960s.

The historical Chinese texts do describe specific interventions at specific points on the body of the horse, and they include detailed charts and diagrams to guide these interventions. Such charts are often presented in modern works, without translation of labels or inclusion of accompanying text from the original works, as evidence of historical acupuncture point designations. Actually reading the text associated with such diagrams makes it clear that these are not charts showing acupuncture points or meridians. In reality, most such charts for animals date back no further than the 1970s. (For a more detailed look at the history of veterinary acupuncture, see Dr. Ramey’s book Complementary and Alternative Veterinary Medicine Considered).

The authors of the Sudhoff Archiv article also describe some of  the remarkable similarities between Chinese veterinary practices and those described in Greek, Roman, and other Western cultures. I don’t have the expertise to judge the plausibility of their suggestion that some of this similarity may be due to the spread of ideas from the West into China via Arab or Indian sources. Though I would not be at all surprised if disparate cultures came up with very similar theories about unseen forces responsible for disease and methods of manipulating these forces, it is an interesting hypothesis that the similarities are more direct.

Overall, the article is a detailed scholarly look at the truth about early Chinese equine medicine, and veterinary medicine more generally. It is particularly helpful in challenging the many inaccurate claims about the antiquity of veterinary acupuncture. While I do not believe the antiquity of a medical practice is useful in assessing its validity, it is a compelling argument for some, so knowing the truth about this particular practice is of more than just academic interest.

Posted in Acupuncture | 9 Comments

A New Tool for Evaluating the Effects of Arthritis Treatments in Dogs

Posted on July 7, 2010 by skeptvet

There is an excellent article in the current issue of the Journal of the American Veterinary Medical Association which I wanted to draw attention to, both for its conttent and the design of the study.

Brown,D.C.; Boston,R.C.; Farrar,J.T. Use of an activity monitor to detect response to treatment in dogs with osteoarthritis. J.Am.Vet.Med.Assoc. 2010, 237, 1, 66-70.

A perennial problem in the evaluation of any therapy for arthritis in animals is the difficulty in assessing effect. Most studies use subjective evaluations by investigators or owners, which are subject to many kinds of bias and almost always show a benefit of every therapy for at least some of the multiple measures of function evaluated. A few studies use force plate analysis, where the dog walks over a device that measures how much weight they place on an arthritic limb. But this is a complex and often difficult measurement to take. The recent article describes a study using a small accelerometer to measure activity at home over a prolonged period. This is potentially a very useful tool in evaluating the efficacy of arthritis treatments in dogs.

The study was very well designed, and the authors clearly recognized the importance of controlling for investigator and owner bias even when using an objective measurement tool. The patients were randomized to treatment either with an agent already clearly established as effective (the NSAID Rimadyl) or an identical placebo, and both investigators and owners were blinded to the group assignment. Confounding factors were controlled for by selecting a study population newly diagnosed and not already treated, and by using statistical techniques to account for factors such as age, weight, and so on.

The results showed an expected increase in activity for the patients given Rimadyl (about 20% greater activity than before treatment) and no change from baseline for the placebo group. Interestingly, some of the dogs in the placebo group did show an increase in activity (20% of the dogs in this group had an increase of 10-30% in activity from the baseline period). As the authors explained, this sort of change likely represents the phenomenon of regression to the mean. For many chronic diseases, including arthritis, the symptoms wax and wane, getting worse and better alternately around an average, or mean, degree of severity. People tend to seek medical treatment, for themselves and their pets, when their symptoms are especially bad, and so the natural course of the disease tends to lead to an improvement in symptoms following an intervention regardless of whether the intervention is actually doing anything. Add to this the tendency for people to behave differently when involved in a medical study, usually exhibiting better health habits than they usually do, and it is routine for studies to show improvement with placebo therapies that aren’t actually doing anything. This is a significant contributor to the so-called “placebo effect.” It also explains why adequate controls are critical to showing real treatment effects, and why poorly controlled studies tend to find effects where they don’t really exist.

I am hopeful that the monitoring device discussed in this article will make it possible to more easily and inexpensively evaluate the effectiveness of the various purported osteoarthritis treatments currently in use as well as new treatments. I am less hopeful that such future studies will be as carefully designed and controlled as this one. Objective measures and all the statistics in the world don’t make experimental results real or useful unless human bias is adequately compensated for through techniques such as random allocation of subjects, blinding of investigators and owners, and placebo controls, or ideally a combination of active and placebo controls as well as no treatment at all. This study is a nice example of how such techniques should be used, as well as a demonstration of why they are needed.

Posted in Science-Based Veterinary Medicine | 3 Comments

Raw Pet Diet and “Natural” Pet Product Recalls

Posted on July 6, 2010 by skeptvet

One of the comments often made in defense of raw diets and challenging the safety  of conventional commercial pet foods is, “If those foods are so safe, why are they always being recalled?” The implication, of course, is that a recall is an indication a food is unsafe. The reality is that while this is sometimes true, many recalls are precautionary, and a real health threat is often not found when the recalled product is analyzed. This information, however, rarely gets the widespread coverage in the media or on the internet that the original recall did.

In any case, even if the suggestion that how many recalls one can remember for a given company or type of food was a reliable guide to safety, it is simply not true that alternative products or those marketed as “natural” and so on are not recalled. I don’t have any statistical analysis comparing the relative rate of recalls, precautionary or related to confirmed health threats, for all the pet food products out there, but it is easy to find examples of recalls involving raw diets, “natural” diets and supplements, and other products marketed as safer or healthier than conventional foods and treats. Dr. Susan Wynn, a veterinarian with specialty training in nutrition and an advocate of many veterinary CAM approaches, frequently reports such recalls on her blog, including several recently involving a raw diet for cats contaminated with Salmonella, and a long list of vitamins and supplements, also with possible Salmonella contamination.

These particular products may or may not present a danger to animal or human health, and certainly if there is a possibility that they do then voluntarily recalling them is the responsible thing for their manufacturers to do. But it’s important to remember that the claims of greater safety or health benefits from raw diets or supposedly “natural” food products are not substantiated by any evidence, and that these products, like any other, can have risks.

Posted in Nutrition | 5 Comments

Vet Stem’s Stem Cell Therapy and Chemaphor’s Oximunol Join Forces

Posted on June 30, 2010 by skeptvet

I recently ran across a press release which identified a business relationship I found interesting. Apparently, the Canadian company Chemaphor, maker of the nutritional supplement Oximunol which I have discussed in the past, has entered into a licensing arrangement with Vet Stem, an American company marketing fat-derived stem cells in animals as a treatment for arthritis and other orthopedic problems as well as, potentially, just about any other disease under the sun. This will make it possible for the Vet Stem process to be marketed in Canada.

I haven’t addressed the Vet Stem marketing issue directly here, but I’ve been involved in some discussions on the subject elsewhere. As I pointed out in my recent post about stem cell therapy in general, the approach has significant biologic plausibility and some supportive in vitro and animal model evidence to suggest it may someday be a valuable clinical therapy. Unfortunately, the selling of it as a product for humans and, primarily via Vet Stem, for pets, is far out in front of the evidence that this hope will be borne out in the real world. For example, the only clinical research I have yet found concerning autologous fat-derived stem cell treatment for dogs is two papers, both funded by Vet Stem.

1. Black, L. L., Gaynor, J., Adams, C., Dhupa, S., Sams, A. E., Taylor, R., et al. (2008). Effect of intraarticular injection of autologous adipose-derived mesenchymal stem and regenerative cells on clinical signs of chronic osteoarthritis of the elbow joint in dogs. Veterinary Therapeutics : Research in Applied Veterinary Medicine, 9(3), 192-200.

2. Black, L. L., Gaynor, J., Gahring, D., Adams, C., Aron, D., Harman, S., et al. (2007). Effect of adipose-derived mesenchymal stem and regenerative cells on lameness in dogs with chronic osteoarthritis of the coxofemoral joints: A randomized, double-blinded, multicenter, controlled trial. Veterinary Therapeutics : Research in Applied Veterinary Medicine, 8(4), 272-284.

The first lacked a placebo or standard treatment control, blinding, and randomization, so it essentially amounted to an uncontrolled case series funded and evaluated by the company selling the therapy. Both investigator and owner subjective evaluations showed changes in some measures, up to about 30-40% improvement at the most. This cannot be distinguished from a non-specific experimental effect with this design.

The second was reported as a double-blinded, placebo controlled randomized study, though the details of these controls were not reported. There was a 14% dropout, which is not excessive though it is difficult to tell if it would have changed the statistical outcomes given that dropouts in studies tend to be treatment failures. Of 13 measures evaluated by investigators, there were statistically significant differences in 3 when the data for all investigators was pooled (none for investigators singly, obviously with smaller sample sizes). Of the subjective owner evaluations, 13 measures graded on a 5-point scale, 1.9 measures improved by >/= 2 points in the placebo group and 4.7 measures by >/= 2 points in the treatment group, but this was not statistically significant (and 5 of the 18 dogs that completed the study were not included in this evaluation for a variety of reasons).

Both of these studies do provide some support for the claim that fat-derived autologous stem cell injections may have clinical benefit for the conditions examined, but the evidence they provide is very weak due to limitations in the study size, design, and possible biases. My concern is that such weak evidence, even added to the suggestive pre-clinical information and to study results from other species, does not justify selling an invasive and expensive medical procedure to pet owners. At best, the therapy should be offered as an experimental intervention with strict informed consent guidelines and a system for evaluating outcomes that is as objective as possible and as independent as possible of the company hoping to profit from the therapy. The situation is similar for other species that Vet Stem offers to treat, though there is a bit more clinical evidence for horses.

Similarly, the Chemaphor product Oximunol is supported only by theory and in vitro studies with no published clinical trial evidence to suggest safety or efficacy in veterinary patients. Even under the lax standards of regulation applied to nutritional supplements, the company would likely not be allowed to make the medical claims for the product they make in marketing materials, but they specifically acknowledge pursuing the veterinary nutraceutical market partly because they face “lower regulatory hurdles” than the human market. In their current press release, the company states ” With the recent announcement of the Vet-Stem stem cell licensing arrangement, Chemaphor is evaluating the establishment of a sales team to promote the use of Oximunol(TM) Chewables as well as the Vet-Stem products for companion animals.”

The two companies clearly see a synergy between their products and corporate philosophies. Unfortunately, the common bond seems to be a desire to rapidly and effectively market medical therapies in advance of adequate safety and efficacy data. The regulatory structures applied to medical devices and drugs in the U.S. by the FDA are not capricious bureaucratic hurdles, they are the response to a series of medical tragedies in which the public was harmed by therapies that had not been adequately tested. The exemptions to this process offered by DSHEA, and by the pragmatic inability of the FDA to enforce existing rules in veterinary medicine, should be understood as weaknesses and a danger to the public, not opportunities. I have little doubt that the promoters of these therapies believe they are safe and beneficial, and the current state of the evidence does not by any means show they are wrong. But the history of medicine makes it clear that such faith often turns out to be misplaced, and that shortcutting the process of vetting new therapies does more harm than good. We can only hope that does not turn out to be the case with these products.

Posted in General, Herbs and Supplements, Science-Based Veterinary Medicine | 6 Comments

Edzard Ernst on How to Spot Medical Nonsense

Posted on June 25, 2010 by skeptvet

Edzard Ernst is well known as an “insider” in the world of alternative medicine who has come to see the need for rational, scientific analysis and evidence to justify inflicting any treatment of whatever provenance on patients. His book, with Simon Singh, Trick or treatment: The Undeniable Facts About Alternative Medicine, which I have previously reviewed, is a model for how to look scientifically and CAM, and it is an indispensible resource for anyone interested in the truth about alternative approaches.

Ernst has a new short article in the oxymoronically named journal Evidence-Based Complementary and Alternative Medicine. The unfortunate title of this otherwise useful article is Winnowing the Chaff of Charlatanism from the Wheat of Science.

In his article, Ernst suggests a possible strategy for evaluating medical claims. It is not especially novel, but it’s a clear introduction to some of the key methods by which nonsense can be distinguished from real science.

The first test is Karl Popper’s time-honored concept of falsifiability. At its simplest, this just means that it is possible for a claim to be proven false. If, for example, all disease is claimed to be caused by vertebral subluxations, then showing that any disease has another cause demonstrates this claim to be false. Many CAM approaches rely on mystical “energies” that can only be intuited, and many practitioners claim that the methods or even the skeptical attitudes of scientific researchers interfere with their treatments, so these treatments can never be tested and are, in either theory or practice, unfalsifiable. Unfortunately, many CAM proponents will argue that their approaches are theoretically falsifiable but we simply do not yet have the technology or methods to test them, so they squirm out of meeting this criterion.

Ernst then suggests moving on the test of plausibility. This is one of the concepts which separates the close but not identical domains of evidence-based medicine from more generally science-based medicine. If an idea is inconsistent with well-established scientific knowledge, then we can reasonably dismiss the idea right there, without wasting resources testing it empirically. The theories of Alternative Flight are sufficiently implausible that no one has serious suggested we test them. This criterion will also not successfully contain all pseudoscientific nonsense, because it is always possible to claim, with some justification though disingenuously in most cases, that what is plausible is based on current knowledge, and this is incomplete and imperfect. Powered human flight would have seemed extremely implausible 500 years ago, and yet it is possible, so plausibility is not always by itself a sufficient basis for final judgment of a claim.

Finally, Ernst moves on to warning signs of quackery as another criterion to help separate real science from pseudoscience. I have written about these a number of times (my own partial list, and Dr. Walt’s list), and there is significant overlap between other lists of such signs and Dr. Ernst’s. He refers to advocates of quackery as Proponents of Absurd Claims (PACs), and he describes some of the red flags they often wave about:

Intolerance: Many PACs are consumed with evangelic zeal and find it hard to accept or even consider well-reasoned criticism or debate. Anyone who has tried to have a rational discussion with someone making irrational claims will have experienced this phenomenon. As intolerance can exist everywhere, its discriminating power is, of course, low and further criteria are required.

Selectivity: Most PACs tend to ignore facts that contradict their own assumptions. Instead they favor selected anomalous data or anecdotal findings which apparently support their notions. Clinical trials, for instance, are designed to overcome the many biases associated with simple observation. Whenever their results fail to confirm their belief, PACs insist that, for this or that reason, case reports, observational studies or years of experience are preferable. In arguing their case, PACs often seem to first formulate their conclusions, then selectively identify those bits of information that apparently confirm them.

Paranoia: Many PACs believe in conspiracy theories which posit that ‘the establishment’ is determined to suppress their views or findings. The world wide web, for instance, is full with suggestions that ‘big pharma’ is conducting a campaign against ‘alternative cancer cures’ such as laetrile or shark cartilage. Anyone who points out what the evidence really shows is likely to be accused of being part of the conspiracy.

Misuse: Some PACs misuse science, for instance, by using terminology like energy, chaos theory, quantum mechanics or entanglement in inappropriate contexts, devoid of their actual meanings. Accepted standards are rejected and double standards are proposed for their own area. In case this strategy fails, other means might be employed, including outright fraud.

I wouldn’t suggest Ernst’s criteria are foolproof, and neither does he, but it is a nice simple starting point, especially for those not steeped in skepticism and already familiar with the many dodges, obfuscations, and deceptive marketing techniques of the CAM world.

Posted in General | 13 Comments

Stem Cell Therapy– Still an Uncontrolled Experiment on our Pets

Posted on June 23, 2010 by skeptvet

Dr. Steven Novella at Science-Based Medicine recently posted about a publication from the International Society for Stem Cell Research which cautions people seeking stem cell therapies that most such treatments are unproven and experimental. This is an especially compelling advisory coming, as it does, from an organization committed to the study of stem cell therapies, and so presumably positively biased in favor of these treatments, at least in principle. It shows an impressive degree of scientific integrity.

The portions of the document that are most telling are the general introduction and the discussion of the limitations of current evidence for stem cell treatments, as well as the discussion of the need for detailed informed consent prior to any use of such therapies, given that they are experimental. In the introduction, the organization states:

We have all heard about the extraordinary promise that stem cell research holds for the treatment of a wide range of diseases and conditions. However, there is a lot of work still needed to take this research and turn it into safe and effective treatments.

The International Society for Stem Cell Research (ISSCR) is very concerned that stem cell therapies are being sold around the world before they have been proven safe and effective.

Stem cell therapies are nearly all new and experimental. In these early stages, they may not work, and there may be downsides. Make sure you understand what to look out for before considering a stem cell therapy.

Remember, most medical discoveries are based on years of research performed at universities and companies. There is a long process that shows first in laboratory studies and then in clinical research that something is safe and will work. Like a new drug, stem cell therapies must be assessed and meet certain standards before receiving approval from national regulatory bodies to be used to treat people.

In answer to the question “For what diseases or conditions are stem cell treatments well established?” they write:

The range of diseases for which there are proven treatments based on stem cells is still extremely small. Disorders of the blood and immune system and acquired loss of bone marrow function can, in some cases, be treated effectively with blood stem cell transplantation.

Doctors have been transferring blood stem cells by bone marrow transplant for more than 50 years, and advanced techniques for collecting blood stem cells are now used clinically. Umbilical cord blood, like bone marrow, is often collected as a source of blood stem cells and is being used experimentally as an alternative to bone marrow in transplantation.

Other tissue-specific stem cells may also play a role in tissue transplants that have been performed for several years. For tissues and organs such as skin and cornea, stem cells contained in these tissues contribute to long-term regeneration.

Other stem cell treatments are still experimental. This means that it has not yet been shown that this treatment is safe or that it will work.

This is clearly all the more true in veterinary medicine, where the sources of stem cells are sometimes atypical (such as fat-derived autologous cells) and the amount of good quality clinical research on the safety and effectiveness of such treatments is close to nil. And yet, these therapies are being sold and used in clinical practice, quite likely without the kind of detailed informed consent, assiduous follow-up, or other controls for bias and risk that would be expected in a clinical trial.

Once again, this is an example of a plausible therapy rushed to market without adequate evidence of safety or benefit. Such therapies rarely live up to their initial promise, and they expose the public to unnecessary risk as well as false hope. They also expose the professions of scientific medicine to rightly criticism about the impact of profit motive on our behavior, and to less legitimate criticism about the dangers of conventional medicine (and you know what will be suggested as the alternative….). We have a responsibility to our patients, clients, and our profession to be cautious in utilizing unproven treatments and in making sure clients understand the uncertain risks of such procedures.

Posted in Science-Based Veterinary Medicine | 11 Comments

Pheromone Therapy for Dogs and Cats–What’s the Evidence?

Posted on June 22, 2010 by skeptvet

Behavioral problems, especially fear and aggression in dogs and elimination in the house in both dogs and cats, are a major reason for people to give up or euthanize their pets, so they represent a serious medical condition. There are many methods of treating such disorders with behavioral modification, and medications can sometimes be helpful, though our understand of which medications might help for which problems in which patients is very poor. However, the sad truth is that we have very limited success in alleviating many of these problems.

In the face of serious medical problems for which there are not strikingly effective scientific therapies, more questionable methods can become widely used. Some, like Bach flower essences, such as Rescue Remedy, or homeopathic treatments are clearly useless nonsense. Others are plausible scientifically, but not really shown to work in definitive ways. One such treatment is the use of pheromones.

Pheromones are chemicals animals produce that can affect the behavior of other members of the same species. They are believed to be common and important in coordinating social behavior in animals, especially mammals. The role, if any, that they play in human behavior is less clear, though they may be involved in the synchronizing of menstrual cycles in women living together. In any case, it is clearly reasonable that such substances might have an impact on the behavior of dogs and cats and so might be useful in managing behavior problems. Notice all the “mights” in that statement? The devil, of course, is in the details

It has become quite common for veterinarians to recommend use of synthetic pheromone analogs, that is chemicals made to be structurally  natural pheromones, to help treat behavioral problems. The most common products are Feliway, and analogue of the facial pheromone cats leave behind on furniture and people the rub their faces against, and DAP, short for Dog Appeasing Pheromones, a pheromone nursing mothers release which is believed to calm puppies. These are sold with dramatic claims of efficacy for a wide range of conditions, but of course the claims of folks selling the product have to be viewed as perhaps less objective than other forms of evidence.

In the most recent issue of the Journal of the American Veterinary Medical Association, a systematic review was published which evaluated the research evidence for the use of these products.

Frank,D. Beauchamp,G. Palestrini,C. Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs. J.Am.Vet.Med.Assoc., 2010, 236, 12, 1308-1316.

The purpose of a systematic review is to evaluate all the published data on the basis of quality, and then evaluate the results of studies that meet a reasonable minimum quality. In this review, studies were excluded that did not meet minimum quality standards or that were conducted by researchers working for the company selling the product under study. This left a total of 14 studies, 7 in cats and 7 in dogs.

In general, as is too often the case in veterinary medicine, the methodological quality of the studies overall was lower than expected in human medicine, with no studies reaching the highest standards. But as the authors wisely note, imperfect information is better than no information, so we must make our judgments based on the best available evidence even if it is prone to errors that better studies would avoid.  I will spare you the interesting but complex details of the various study designs and their strengths and weaknesses, though reading the full review is recommended for anyone interested. Having read through the full report, I am convinced that unlike others I have reviewed, the conclusions of the authors of this systematic review are supported by the methods and results they detail elsewhere in the paper.

Of the 7 cat studies, none provided convincing evidence of a benefit. Some decrease in urine spraying occurred in some cats, but the significance of this was muddied by failure to follow up on cats which dropped out of studies, which were probably cats who didn’t improve with the treatment, and other methodological flaws in the studies reviewed. Pheromone therapy also was not clearly of benefit in cats with interstitial cystitis (a condition in which irritation in the bladder causes symptoms much like those of a bladder infection). The pheromone also did not seem beneficial in calming cats in the hospital or facilitating the stressful process of placing IV catheters in hospitalized cats.

In dogs, one study found some evidence that pheromone therapy might reduce anxiety in puppies during training. Other than that, no convincing evidence of benefit was found for anxiety associated with veterinary care, anxiety in shelter dogs, or barking and elimination indoors by recently adopted dogs.

The limitations in the quality of the evidence mean we cannot definitively declare that pheromone therapy doesn’t work. What we can say is that based on the best evidence to date, it does not appear to have a benefit. Further study is certainly reasonable, but as always I question the wisdom and the ethics of widespread sale and use of products which, despite years of testing, don’t seem to have much evidence that they work. These products appear harmless, and if clients wish to spend money rolling the dice on a treatment that is not well supported by the limited clinical research available that is certainly up to them. But when veterinarians recommend such products, it does tend to convey the impression that they are legitimate, validated therapies, and I think we do a disservice to our clients if we make such recommendations without a clear statement of the limitations in the evidence. Thanks to this paper, it is now easier to make such a statement.

Posted in Science-Based Veterinary Medicine | 71 Comments