Traditional Chinese Veterinary Medicine

Posted on May 22, 2011 by skeptvet

What Is It?
Traditional Chinese Medicine (TCM) is marketed as a set of theories and practices developed over centuries in China. In reality, it is a label applied to a varied and inconsistent set of practices drawn from a variety of competing traditions, as well as many modern innovations. The term “traditional” is a misnomer for the companion animal applications  of TCM in particular, since historically most TCM concepts and techniques were not applied to pets. The more abstract theories were only held to apply to humans, and the pragmatic use of herbs and other remedies were mostly reserved for agricultural and working animals.The application of theories and practices under the label of TCM to pets is quite recent. The primary methods of treatment in TCM include acupuncture, herbal remedies, a manipulative therapy called tui-na, and alterations in diet.

Though much historical Chinese folk medicine was pragmatic (applying various treatments to symptoms by trial-and-error) TCM as it is packaged today in the West includes a number of theoretical concepts that are variants of Daoist metaphysics and folk cosmology. The fundamental nature of the universe and everything in it is conceived as a condition of balance between opposing aspects of existence known as Yin and Yang. Cold and heat, dark and light, old and young, and so on are seen as examples of this balance between opposites, and all diseases are believed to arise from a disharmony or loss of balance between Yin and Yang. Infectious organisms, toxins, trauma, and other causes of illness recognized by scientific medicine are not considered as true causes in the TCM paradigm, but as manifestations of disharmony. According to Huisheng Xie, the leading figure in veterinary TCM in the United States, “no disease occurs if Yin and Yang maintain a relative balance.”

Yin and Yang are also identified with particular temperaments, organs of the body, seasons, and other features of living organisms and the environment, and this is taken to illustrate the centrality of these concepts and the balance between them to all features of the universe. This notion of balance between forces represented by the five elements (earth, air, fire, water, and wood) or bodily fluids  bears a strong resemblance to the humorism of ancient Greece and Rome, India, and many other cultures. Humorism, practiced in the West until the twentieth century, identified imbalance in humors (blood/air, yellow bile/fire, black bile/earth, and phlegm/water) as the cause of all disease and associated these humors with pairs of opposites such as heat and cold, winter and summer, and so on. Practitioners of humorism attempted to maintain and restore health by restoring balance among the humors, much as TCM practitioners attempt to rebalance Yin and Yang. This was accomplished through bloodletting, herbal remedies, cauterization, and many other practices common to historical and contemporary TCM. This humorist model and the associated practices were abandoned in the West with the advent of modern scientific medicine.

The concept of Yin and Yang is applied to health through an intricate system that varies significantly between individual doctors who employ TCM. In general, practitioners evaluate the appearance of the tongue, the pulse, and a host of other characteristics of individual patients to categorize the problem in terms of excess or deficiency of Yin and Yang. Individual treatments are assigned as promoting or reducing Yin and Yang, so the remedies are chosen based on the categorization of the problem. Egg and banana, for example, are cooling foods, while garlic and ginger are warming foods.  Herbs, acupuncture points, and other treatments are assigned in the same way by tradition, taste, or other criteria.

The names of organs are used in categorizing a disorder according to the TCM system, but it is important to note that this is a metaphorical use of these names, associating certain functions and Yin or Yang with certain organs, somewhat like the metaphorical use of the heart as a symbol for strong emotions (as in “He followed his heart”) and the association of bile with bitter or hostile temperament (as in “You’ve got a lot of gall!”). These names do not imply the anatomical or physiological relationships understood in scientific medicine. This makes it possible, for example, to adjust the Gall Bladder function in a species like the horse, which doesn’t actually have a gall bladder.

A couple of case examples from Dr. Xie’s text will illustrate the general thought process of TCVM.

1. Signalment: Seven year old, female spayed Labrador Retriever

Primary Complaint: Separation Anxiety

History ad Physical Findings: From a western perspective, the dog has all the signs of separation anxiety. Acupuncture treatment did not help much. She has been on the herbal formula Long Dan Xie Gan Wan for signs of Liver Stagnation.

Her tongue is slightly red and dry and her gums are tacky. Her eyes are red. Her pulses are thready and fast.

Assessment: This is a Yin Deficiency Pattern (Deficient Heat), specifically a Heart Yin Deficiency pattern. The Yin Deficiency can be determined from the red, dry tongue (Heat signs) and the thready and fast pulse. The association with the Heart is based on the major complaint of separation anxiety because this is due to a Shen (Spirit or Mind) disturbance. Of the five Yin organs, the Heart is the one that houses the Shen. Separation anxiety and other behavior problems are mostly related to the Heart. The treatment strategy is to balance Yin and Yang by enhancing Yin. The acupuncture points An Shen, HT-7, Da Feng Men, and KID-3 as well as the herbal formula Shen Calmer (Modified Tian Wan Bu Xin Dan) are recommended for this case.

 2. Signalment: A thirteen year old female spayed American Eskimo dog.

Problem List:
a. Cushing’s disease which has been treated with Mitotane for the past four years.

b. Seizures which began last month and clustered about once a week.

c. Hypothyroidism

d. Generalized stiffness with weak hind end. There is no limping, but the dog’s gait is very stiff. The dog takes three to four steps then huffs and puffs and lies down.

e. Generalized lethargy, weakness, lack of energy.

Physical Findings: Pulse is thin and fast; Ravenous appetite and thirst; Bilateral cataracts; Deafness; Panting Constantly; Poor teeth and gums; Rose colored thin ocular discharge; Stool dark brown and foul smelling; Chronic urinary incontinence, all day, all the time; Draining pressure sore on left hip; Pot-bellied with muscle wasting; Tongue is pink with thin coating

Assessment: This can be considered a Deficient Heat (Yin Deficiency) condition, with a Qi Deficiency and Internal Wind. The old age, weakness, urinary incontinence and lethargy indicate a Qi Deficiency. The fast pulse, thirst, ravenous appetite, constant panting and foul smelling stool can indicate Heat. Seizures are caused by Internal Wind.

The treatment strategy is to use acupuncture to balance Yin and Yang by enhancing Yin and clearing the Wind. In addition, acupuncture can be used for the stiffnedd while using Chinese Herbal medicine for the internal organ problems. Acupuncture points such as GB-20, LIV-3 and GV-20 may be beneficial for the seizures (Wind). The points KID-3 and SP-6 may be beneficial for Yin. Two herbal formulas may be beneficial: Tian Ma Gou Teng Yin for Internal Wind and Suo Quan Wan for incontinence and Kidney Qi Deficiency.

Clearly, TCM has an intricate theory and methodology. One can undertake years of training and study in this system, and it is possible to obtain advanced degrees, even PhDs in the subject. This can create the impression that the system must be rational or else why would it be so complex and so academic. As I’ve discussed many times before, however, the strength of adherents’ faith in and idea, the number of adherents, or the length of time the idea has been around are not reliable indicators of whether the idea is true. The theories and practices of humorism dominated Western medicine from the time of Ancient Greece into the twentieth century, yet they were mistaken and ineffective. And the appearance of scientific or academic legitimacy conveyed by Tooth Fairy Science and Quackademic Medicine is equally unreliable. Any idea, regardless of its source, must stand or fall on the merits of reliable, objective evidence. And in reality, TCM does not have the lengthy pedigree as a unified and coherent system its proponents claim anyway. And as I’ve discussed in previous articles, it isn’t even all that popular in China.

Does It Work?
So is there such evidence to support the theories and practices of TCM? Well, the theoretical foundations claimed as the basis for TCM involve undetectable energies and spiritual forces, so they amount to a religious belief system more than a model of the functioning of living organisms. This, of course, cannot be tested by any scientific means and so must either be believed on the basis of faith and personal intuition or experience or rejected on the same basis.

These theories have no consistent relationship to the scientific understandings of anatomy, physiology, or other factors in health and disease. Contrary to popular misconceptions, TCM diagnoses and treatment guidelines are not simply a different set of metaphors for describing the same things scientific medicine talks about. Acupuncture points, for example, do not consistently correspond to detectable anatomical features. And as already pointed out, the use of organ names in TCM is purely metaphorical. So the TCM system of understanding health and disease is entirely separate from the scientific system and cannot be integrated with it, whether or not scientific and TCM treatments are used together.

Much of TCM theory and practice cannot be tested scientifically, but some interventions can. Of course, this raises the theoretical issue of whether or not they should be. Since the way medical problems are categorized and interventions are assigned is based on a metaphysical ideology not compatible with scientific explanations of the world, there is no underlying biologic plausibility to these processes. The only reason to consider investigating them seriously is the belief of those who practice and receive them and, which is a deeply unreliable indicator of the validity of ideas generally. Still, on a pragmatic level any method that is sufficiently popular is likely to draw additional adherents on the basis of testimonials alone, particularly with the added  allure of Orientalism TCM has. Therefore it is worthwhile to examine at least some of the claims made for such an approach in an objective scientific way and see if there are any indications of real effects despite the lack of a plausible theoretical foundation and the largely manufactured history claimed for TCM.

Because the TCM system is complex and involves multiple modes of treatment, each of these specific practices must be tested independently. It makes no more sense to ask “Does TCM work?” than it does to ask “Do drugs work?” Penicillin works for certain kinds of bacterial infections, but not for cancer, depression, or a broken toe. Similarly, acupuncture may have detectable effects for some conditions and not for others. Scientific medical research is not about validating or invalidating an entire philosophy or world view, but about identifying the effects of specific interventions on specific problems under specific conditions. If the argument is made that TCM fundamentally cannot be examined in this way, then it must be considered a belief system or faith healing practice, not a branch of medicine, and it should be practiced or dismissed on the basis of personal faith like any other religion. If, however, TCM is to be taken seriously as a medical approach, it must be pass or fail the same tests of legitimacy as any other healthcare approach.

I will look at each of the major branches of TCM treatment separately to discuss the scientific evidence concerning their effects.

1. Acupuncture:
This is probably the most thoroughly studied and understood of the TCM interventions, and I have written about it extensively. In brief, the evidence in humans shows some mild beneficial effects for subjective symptoms such as pain, nausea, depression, and so on. These effects appear to be largely psychological as they can be elicited by needling practices that are “incorrect” according to any of the various semi-official lists of points and methods (or even by non-penetrating needles or poking patients with toothpicks), and they follow the usual patterns of placebo effects (stronger if presented confidently rather than hesitantly, not consistently detectable through blinded, objective measurement variables, etc). It does not appear that the actual physical manifestations or overall course of any disease is significantly altered by acupuncture, but the psychological benefits of the treatment ritual may be sufficiently beneficial for some patients to be worthwhile.

There is little research on the clinical benefits of acupuncture in companion animals, and no replicated, high-quality studies. There is as yet no reason to believe the results of such research would be different from those seen in humans, but the case has not yet been conclusively made. In any case, the confident claims of benefit almost universally made by practitioners of acupuncture are certainly not justified by scientific evidence.

For more information, see my previous posts concerning acupuncture, the Science-Based Medicine acupuncture section, and the excellent summaries in Snake Oil Science by R. Barker Bausell and Trick or Treatment: The undeniable Facts about Alternative Medicine by Edzard Ernst and Simon Singh.

2. Herbal Remedies:
Like herbal medicine in general, this is a complex area in which there is as yet little reliable data. Herbal remedies undoubtedly contain pharmacologically active compounds, so there is reason to believe they could have clinical effects. TCM remedies in particular are often mixtures of multiple plant and animal products, as well as contaminates and often conventional pharmaceuticals, so the pharmacology of these mixtures is complex. Since particular remedies have been assigned by tradition and personal experience to influence Yin and Yang, and since the TCM theories by which they are selected have no relationship to the causes of disease as understood by scientific medicine, there is no scientifically plausible reason to believe these remedies, whatever chemicals they contain, should be safe or effective for particular medical conditions. We have, as usual, only anecdote and tradition to support the use of these products.

A recent article provides an example specific to TCM. Certain fungi that parasitize  insects have been used in TCM practice, as part of the remedy Dong Chong Xia Cao, believed to tonify Yang and promote youth and vitality. Like most ethnobotany traditions, this fungus was used for a great variety of unrelated conditions. It turns out to contain a compound which suppresses inflammation and immune function (despite the inevitable claims that the remedy “enhances” the immune system) and has a variety of other effects in vitro and in lab animals experiments. These functions make this compound potentially useful in the treatment of autoimmune diseases such as multiple sclerosis, once extracted from the original fungus and purified. However, the original substance has unacceptable toxic side effects, so it had to be modified to make it a safe and useful medicine.

This example illustrates quite nicely how the process of identifying and making use of potentially medicinal compounds in plants and other natural sources differs from the haphazard traditional use of herbal products. Advocates of herbal medicine are correct when they claim that many medicines come from plants. What they ignore or fail to mention is that these medicines are almost always safer and more effective once they have been isolated from the chemical soup of whole plant products, tested according to a thorough understanding of the relevant physiology and disease mechanisms, and often modified to be safer and more effective than the original compounds. And these plant-derived medicines frequently turn out to be useful in ways that bear little to no relationship to the traditional uses of the plants themselves.

There have been many studies of Chinese herbal preparations, including in vitro, lab animal studies, and clinical trials. Many of these are problematic in that they are small, of poor methodological quality, and often published in alternative medicine journals and Chinese medical journals, which very rarely publish any negative studies, suggesting a severe publication bias. And from a theoretical point of view, studies of individual Chinese herbal remedies for medical conditions defined in standard scientific terms make little sense. From a scientific point of view, there is no reason to think that plant products selected on the basis of undetectable energies and other mystical concepts should be effective. And from the point of view of TCM, using individual remedies utilized to treat disease as defined by conventional science makes no sense because the appropriate treatment should be comprehensive and individualized diagnosis and management of the patient according to the TCM system.

Nevertheless, some attempts to study these herbal preparations in this hybrid way have been made. Though positive results are occasionally reported, there is no repeatable, high-quality evidence to support the use of any particular remedy for any specific condition, and overall the evidence is sparse, of poor quality, and not encouraging.

Given that there are thousands of plant and animal products that have been used in TCM for innumerable purposes, it would be astounding if a few did not turn out to have some positive effects consistent with their traditional use. It is far more likely, given the existing data and the experience with investigations of other herbal medicine traditions, that most traditional uses will not be validated and that the beneficial compounds in the original materials will only prove beneficial once isolated, purified, modified, and tested according to conventional scientific practices, as with the example of Dong Chong Xia Cao already discussed.

A number of Cochrane Reviews of Chinese Herbal Medicines are available, and they generally report the quality and quantity of the evidence for most indications to be insufficient to justify a recommendation. A systematic review of all individualized herbal medicine studies, including those utilizing TCM, found, “There is a sparsity[sic] of evidence regarding the effectiveness of individualised[sic] herbal medicine and no convincing evidence to support the use of individualised[sic] herbal medicine in any indication.” More research seems appropriate, but not based solely on traditional uses of combination products selected on the basis of metaphysical criteria. As with any pharmacologically active preparation, thee herbs should be studied by first identifying potential active compounds, examining their chemical and biological properties in pre-clinical laboratory testing, verifying their safety, and only then proceeding with clinical trials for those that seem promising.

3. Tui Na:
Tui-Na is a manipulative therapy with features resembling massage and also chiropractic, though it is guided by the same theoretical and traditional principles as acupuncture. It is usually offered in conjunction with acupuncture and the other interventions associated with TCM, and there is a great scarcity of scientific research on its purported effects. It is usually included in global TCM treatment, so few studies exist examining it independent of acupuncture, herbs, and other TCM interventions. One example, looking at tui na for degenerative spinal disease in the neck (cervical spondylosis) found no good evidence of benefit.

It is tempting to lump this therapy in with massage, which like acupuncture has benefits for pain, anxiety, and other symptoms with a significant psychological component but which has not been demonstrated to meaningfully affect the outcome of any specific disease process. However, I have not found any detailed comparisons of different manual therapies and their relative effects, so this would just be speculation.

Is It Safe?
As with efficacy, the safety of TCM has to be evaluated in terms of the individual interventions employed. Acupuncture has known risks, including infections, trauma to nerves and muscles, and even death from inadvertent penetration of the chest with needles, which allows air to enter and collapses the lungs. Recently, the former president of South Korea was seen by doctors for a cough and ended up needing to have an acupuncture needle surgically removed from one of his lungs. A recent review suggests that these risks are small, and can be minimized with proper training and regulation of acupuncturists, but they are not non-existent, and in the face of questionable evidence for real benefits, even small risks seem hard to justify.

The risks of herbal remedies are likely much greater, though they are hard to evaluate in the absence of meaningful government regulation and monitoring. Herbal remedies contain active chemical compounds, and these can have direct toxic effects and they can interfere with other medications. TCM remedies have been repeatedly found to be contaminated with toxic metals, such as lead and mercury, and even conventional pharmaceuticals.

Chinese herbal remedies containing a plant called Aristolochia have been known to cause kidney failure.  Deaths have been caused by the remedy ma huang due to the chemical stimulants it contains, and this product has been banned by the Food and Drug Administration (FDA). And herbal remedies have been found to be contaminated with lead and other toxins as well as pharmaceuticals. A list of references below is given illustrating the considerable risks associated with untested and unregulated herbal preparations in general, including TCM remedies, can be found here.

I am not aware of any reports of harm from tui na therapy.

Bottom Line
The theoretical concepted promoted as the rationale for Traditional Chinese Medicine are essentially religious in their origins. They do not correlate with recognized physical phenomena understood by science, and they apparently cannot be evaluated by scientific means. The specific interventions employed in TCM, acupuncture, herbal remedies, tui na, and dietary manipulation, have not been extensively evaluated through high-quality controlled clinical testing. By far the most research has been conducted on acupuncture, which appears to have placebo benefits for subjective symptoms regardless of whether it is applied according to TCM principles or not. Most herbal remedies in TCM have not been scientifically evaluated. A few have shown promise for some conditions, but a few have also proven deadly, and potentially dangerous contamination with toxins and undisclosed pharmaceuticals is apparently common. There is no reliable evidence base concerning the safety or efficacy of TCM for pets. The few studies available do not show a consistent pattern of significant benefits.

Posted in Acupuncture, General, Herbs and Supplements | 36 Comments

The Economist says, “There is no alternative medicine.”

Posted on May 22, 2011 by skeptvet

It’s rare to see the popular press cover alternative medicine in anything but a friendly way. Because those selling CAM are selling hope and faith as an integral part of most of their remedies, there tends to be a positive feeling in the public’s mind about these approaches even when the facts don’t support the specific claims being made. However, The Economist recently published two stories which say what I think the public most needs to hear about CAM in general: Most of it doesn’t actually work as medicine but it does have clear placebo effects.

One article, entitled There is No Alternative Medicine, puts it quite clearly (though I’m a bit skeptical that the specific percentage provided is reliable):

A few treatments (mostly herbs containing active drug molecules) do have proven benefits. A few others look worthy of further investigation. But from acupuncture, via homeopathy, to “quantum healing”, the vast majority, some 95%, offer nothing more than the placebo effect…

Globally, the industry is estimated to be worth some $60 billion a year. That is a lot to pay for placebos.

The world’s advertising-standards offices should thus crack down on bogus claims—including the idea that there is such a thing as “alternative medicine” in the first place. If it works, it is a medicine and should be regulated like one.

…the alternative-medicine industry plainly excels as a placebo delivery service.

I do think the author goes a bit too far in crediting the placebo effect with true improvements in a patient’s state of health, rather than improvements only in how the patient feels, which is a quite different, though still very important, thing. The evidence that placebo effects actually change the course of disease is very weak, and their primary benefit seems to be in alleviating highly subjective symptoms such as pain, nausea, depression, and so on.

Nevertheless, I agree that there are lessons to be learned from the success of the alternative medicine industry, and that chief among these is that science-based medicine must find ways to provide the same kind of psychological support people find in their CAM therapists without giving up rigorous scientific standards of evidence for the actual safety and efficacy of our interventions.

The second article, Think Yourself Better, makes this point in more detail, focusing on the work of Edzard Ernst in revealing the lack of good evidence for biological effects of most alternative therapies while also pointing out that people seek these therapies despite their lack of effectiveness because of the psychological support and comfort they provide. The tremendous success of scientific medicine is based on the principle that therapies cannot be justified only because they “seem” to work but that they must also be validated by controlled research that eliminates the influence of human psychology and cognitive weaknesses on the results. However, as strongly as I support that approach, I agree that in the real world of patient care, even in veterinary medicine, human psychology plays a critical role in the success of failure of our attempts as clinicians to manage the health of our patients. We need to stick to our epistemological guns and be certain we are offering truly effective therapies, but we also need to be effectively supportive of our patients or clients feelings about health and disease. If we are unable to do this, due to constraints on time or resources, deficits in our training, or other factors, then our clients will continue to be vulnerable to being sold ineffective therapies provided in ways that meet the psychological needs associated with their health even when they don’t meet the biological needs healthcare interventions should meet as a basic precondition of being employed.

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From SBM: The Top Ten Pet Supplements–Do They Work?

Posted on May 19, 2011 by skeptvet

From Science-Based Medicine: The Top Ten Pet Supplements–Do They Work?

An Embarrassment of Riches?
Much has been written here about the dietary supplement industry, a multibillion dollar industry with powerful political connections, and about the woeful inadequacy of regulation which allows widespread marketing of supplements without a solid basis in science or scientific evidence.

The veterinary supplement market is a pittance compared to the human market, but still a billion-dollar pittance that is growing rapidly. Unfortunately, the resources available for good quality research in veterinary healthcare are also a pittance, and it is not at all unusually for our pets to suffer, or even be euthanized, as a result of treatable diseases for want of money to pay for needed care. So $1 billion a year spent on nutritional supplements may not be such a good deal if these products don’t effectively prevent or treat disease.

The variety of supplements available is staggering. Many proprietary concoctions of vitamins, minerals, herbs, and other ingredients are marketed for health maintenance, “boosting the immune system,” retarding aging, or treating specific diseases. A comprehensive review of this multitude of moving targets is impossible. But the lion’s share of the pet supplement market goes to a few specific compounds, so I will focus on these. Most of these ingredients are also among the most popular supplements for humans, with a few exceptions, so there will be substantial overlap with previous discussions of the plausibility and evidence for many of these substances.

1. Glucosamine
The biggest name in the veterinary supplement world by a large margin is glucosamine. It is sold alone or in combination with chondroitin, MSM, green-lipped mussle extract, and a zillion other ingredients. It is sold over-the-counter and through veterinarians and as an additive in commercial pet foods, and it is ubiquitous. It is also widely believed by pet owners and veterinarians to be an effective treatment for osteoarthritis.

Glucosamine for arthritis in humans has been discussed at length here before. There is some reasonable plausibility to the underlying theory, but decades of clinical trials have failed to find any consistent benefit, and the balance of the evidence strongly suggests it is no better than a placebo in treating arthritis in humans. Given the subjective nature of pain and the multitude of ways biologically inert interventions can influence people’s perceptions of their own discomfort, this placebo effect might be of marginal value in humans, but the same kind of psychology does not apply to dogs and cats, though it certainly does apply to their owners.

There is very little clinical research on glucosamine as a treatment for arthritis in dogs and cats. In preparing a recent brief literature review, I found only two clinical trials in dogs. One found no benefit for glucosamine and the other, which had a weaker design, showed little benefit. Both showed far greater and more predictable benefit to non-steroidal anti-inflammatory (NSAID) therapy, which is a consistent feature of clinical research on glucosamine.

Because cats are poorly tolerant of NSAIDs, there is particularly great interest in glucosamine and other nutraceutical therapies for osteoarthritis in this species. Nevertheless, I have found no published clinical trials studying this supplement in arthritis cats. The closest is a study of a diet containing glucosamine, chondroitin, and a number of other supplements purported to have benefits in managing arthritis. I have addressed this study in detail elsewhere, but in brief there were not consistent differences between the experimental diet and the control diet even on subjective measures of comfort and no differences at all on objective measures of activity. And, of course, the role of glucosamine, if any, in any effect that might have been seen would not be demonstrable in a study of a diet with many other ingredients.

Glucosamine is also marketed for treatment of feline interstitial cystitis, an uncomfortable and potentially very serious chronic inflammatory disease of the urinary bladder. However, the only clinical trial to investigate this use did not find any evidence of benefit.

2. Fish Oil
After glucosamine, one of the most popular supplements for pets is fish oil. In humans, the most common use of this supplement is for lowering blood lipid levels and prevention of cardiovascular disease. There is some controversy about exactly how much of which components is useful for which specific conditions, and whether eating fish is better than taking fish oil supplements, but in general there is good evidence for some benefit in cardiovascular disease prevention.

Cats and dogs don’t have the problems humans do with atherosclerosis and cardiovascular disease, so this is not a reason for use of fish oils. Instead, this supplement is most commonly used in the treatment of skin allergies. A 2010 narrative review of the evidence for various approaches to treating canine skin allergies concluded that there was some evidence that fish oil supplements can improve coat quality and reduce the dosage of steroid medications needed to control itching, but that these effects are small and not great enough to substitute for other therapies. There is also not evidence to support the use of any particular source, dosage, or formulation of fish oil over any other.

The other common use of fish oils in pets is for treatment of arthritis. There is weak evidence in humans for the use of fish oil supplements as an adjunctive treatment in patients with rheumatoid arthritis, but in general this is not a well-supported intervention for degenerative osteoarthritis in people. There have been several studies of fish oil as a therapy for osteoarthritis in dogs, which I have reviewed in detail (here and here). These are pretty well-designed studies, all by the same group of investigators, and as is common for studies of dietary supplements, they report mostly negative results but then focus on the few statistically significant findings, generally with subjective measures, to conclude the studies are proof of a benefit. The idea that fish oil supplements might have some small benefit for arthritis in dogs and cats is not out of the question, but so far the evidence is not encouraging.

3. Probiotics
Mark Crislip has eloquently addressed the theory and science of probiotics for humans, and the bottom line for pets appears to be much the same. We understand very little about the important and complex ecology of the gastrointestinal tract, about what bugs are there and what they do for or to us. So while the idea of influencing this flora to restore or maintain health makes some sense, adding a few Lactobacillus to the mix and expecting it to have a major effect seems a bit like tossing a few grass seeds into the Amazon rain forest and expecting a golf course to grow there (thanks Mark!).

Clinical studies in humans support some benefits for some conditions, particularly antibiotic-associated diarrhea, but many of the claims made for probiotic products, especially for health maintenance or “boosting the immune system” are unsupported. There is less research on probiotics for dogs and cats, but there are some encouraging studies which show a likely benefit of some products for acute idiopathic diarrhea in dogs (e.g. here and here, analyzed in detail here). There are also serious problems with the quality control of largely unregulated veterinary probiotics. A recent study found the majority of products tested had inaccurate labels, with many not containing the amount or species of organisms claimed on the label. There are also many products marketed with ridiculous and completely unsupported claims.

So overall, the idea of probiotics as a therapy for gastrointestinal disease seems promising, and there are some early suggestions that some products may be useful for some conditions. But this optimism must be tempered by the very limited, preliminary understanding we have of gut ecology and how to manipulate it, the minimal reliable clinical trial evidence to support probiotic use, and the concerns about poor quality control and exaggerated, unscientific claims for probiotic products.

4. Multivitamins
Multivitamins are widely touted as a preventative health measure or as “insurance” for a nutritionally imperfect diet. As Harriet Hall has discussed previously, taking a multivitamin is more a form of self-administered psychotherapy than a preventative health practice. A 2006 review of the available evidence, as well as more recent studies, do not support claims of health benefits in humans from vitamin supplementation in the absence of confirmed deficiencies. And there are circumstances in which vitamin supplementation can be harmful (for example raising cancer risk, interfering with cancer therapy, or even increasing mortality).

As usual, there is virtually no research on the subject in dogs and cats. Commercial pet diets are nutritionally balanced in a way that the rather haphazard eating habits of most humans is not, so there is even less reason to think a multivitamin would be necessary in dogs and cats eating such a diet. In fact, such supplementation could very well lead to excessive, even toxic levels of fat soluble vitamins or some minerals. Homemade and raw food pet diets, however, are more likely to be nutritionally inadequate, so multivitamin supplementation might be more appropriate when feeding such diets. However, the bottom line is there is no good quality epidemiological or experimental research to suggest that dietary deficiencies are common or that non-targeted vitamin supplementation of apparently healthy pets eating a balanced diet has any value. And there is some evidence that supplementation under certain circumstances can be harmful (for example, calcium in growing large-breed dogs).

The lack of evidence may preclude a definitive statement that such supplements are unnecessary or harmful, but it also makes the confident, sweeping claims of supplement marketers entirely unjustified.

5. Lysine
Lysine is an amino acid which is hypothesized to be useful in the prevention and treatment of Feline Herpesvirus (FHV-1) infections. This virus is extremely common, and many cats will be exposed and become infected as kittens. Clinical symptoms include sneezing, nasal congestion, and conjunctivitis, and they range from mild and self-limiting to very severe. Most cats will get over the initial infection, but many remain chronically infected. With suppression of immune function from stress, medication, or disease, the virus can re-emerge and cause symptoms again. A small subset of cats may develop chronic, ongoing symptoms associated with this infection. Vaccination reduces the severity of symptoms but does not prevent infection.

Lysine is proposed to interfere with the replication of FHV-1 by blocking the uptake of another amino acid, arginine. There are theoretical concerns that lysine supplementation could make cats arginine deficient, but experimental studies suggest this is unlikely in practice. So it appears to be safe, but does it work?

Well, maybe. For once, numerous studies have been done, but there is no clear, consistent pattern of results. Some show that oral supplementation is ineffective and might even make infection worse (Drazenovich, 2009; Rees, 2008; Maggs, 2007). Others do seem to demonstrate some benefit (Maggs, 2003; Stiles, 2002). So while lysine supplementation appears to be safe and there is a plausible rationale for its use, no definitive conclusion about its efficacy is justified.

6. Milk Thistle
Milk thistle is an herbal product that is widely recommended and used. Like glucosamine, it is a supplement which has leapt over the gap between alternative and conventional medicine. The active ingredient is a cluster of compounds called silymarin, There has been extensive in vitro research on silymarin, and it has a wide range of potentially useful effects. It appears to interfere with pro-inflammatory chemicals, functions as an anti-oxidant, and may interfere with the metabolism of some chemicals into toxic compounds in the liver. It also has some activity which could be potentially harmful, including interfering with the metabolism of a number of drugs and stimulating the effects of hormones like estrogen.

The primary uses of silymarin in humans are to protect or treat liver damage from toxins and infectious diseases, to improve the condition of diabetics, and to protect the kidneys from toxins. In dogs and cats the primary use of for non-specific “support” of the liver regardless of the specific disease.

In humans, clinical trial evidence is mixed. A couple of studies have suggested it reduces insulin resistance in diabetic and may lower blood lipid levels. A Cochrane review of 13 studies including 915 people “could not demonstrate significant effects of milk thistle on mortality or complications of liver disease in patients with alcoholic and/or hepatitis B or C liver disease.” High quality trials were negative, and low quality trials suggested a benefit.

Very little research exists in dogs and cats. A small study of 20 cats given acetaminophen, a known liver toxin, found that those given a single oral dose of silymarin did not show the elevation of liver enzyme levels seen in those not given the compound. A similar study in dogs found some differences in elevations of kidney values between those that got silymarin and those that didn’t following exposure to a kidney toxin, though there was not a completely consistent pattern.

A study done in 1978 showed that dogs given a toxic mushroom compound orally and then given silymarin intravenously did not show the increase in liver enzymes that was seen in control dogs. Another in 1984 found that 30% of the control dogs died whereas none of the dogs given IV silymarin along with the mushroom toxin died, and the livers from the treated dogs did not appear damaged by the toxin. What relevance this has for the value of oral supplementation isn’t clear.

As far as risks, there appear to be few. Nausea, diarrhea, and other gastrointestinal effects are sometimes seen in humans and animals, and allergic reactions have been reported in humans.

So overall, the in vitro and laboratory animal evidence indicates it is plausible that milk thistle extract might have beneficial effects, though harmful effects in some situations could be possible as well. In humans, the clinical trials show weak evidence for benefit in some conditions and no evidence of benefit in others. Very little experimental, and apparently no high quality or controlled clinical research exists in dogs and cats. So once again, harm seems unlikely and a benefit is possible for some dose and some form of silymarin in some conditions, but we lack the information to use the compound rationally or to know for certain if it is even useful in most cases.

7. S-adenosyl methionine (SAM-e)
SAM-e is a chemical which occurs throughout the body and has a fascinating array of in vivo functions and in vitro effects. In humans, it is marketed for use in depression and arthritis, and a variety of other conditions. The clinical trial evidence is mixed and not generally high quality (for example, Cochrane Reviews for arthritis and alcoholic liver disease, Mayo Clinic summary for various conditions).

In pets it is primarily promoted as protecting the liver from damage due to disease of toxins, often in combination with Milk Thistle, though its use for arthritis and other conditions is also sometimes recommended. While the theoretical arguments for these uses, especially in the case of liver disease, are plausible, there is virtually no clinical research that the compound actually benefits patients when given as an oral supplement. There is one study which found no significant benefit in preventing liver changes associated with steroid use, one case report claiming some possible benefit in a dog with acetaminophen toxicosis, and one clinical study that suggest some possible value in treating age-related cognitive dysfunction in dogs. And despite how widely used this supplement is, and how sweeping the claims made for it often are, that’s about it.

8. Digestive Enzymes
The claims made for digestive enzyme supplements are often sweeping and dramatic, and they can make you wonder how anyone ever digests their food without them. The usual arguments are that these enzymes exist in raw foods but are destroyed in the production of commercial pet foods, so if you are so foolish as to feed a nutritionally balanced commercial diet, you’d better give your pet these supplements, or else! These exaggerated, unsupported, sometimes outright mythical claims for raw food diets in humans and dogs have been discussed here before. They are based on fundamental misconceptions about digestive physiology and nutrition, and they hold no water.

Healthy humans and dogs have all the enzymes they need to effectively digest foods. The organs that produce such enzymes do not become stressed or fatigued by doing what is, after all, their normal function. Commercial diets and their constituent ingredients are extensively tested for digestibility, and there is no evidence that any deficiency of enzymes in these foods creates nutritional deficiencies or any specific health problem.

In addition to use in healthy individuals, enzymes are also recommended for cancer treatment, anti-inflammatory effects, and treatment of many other disease conditions. Though the occasional study is published to support these recommendations, often in “integrative medicine” journals, there is no consistent, high-quality clinical evidence in humans that digestive enzymes are effective therapy for any condition other than true pancreatic enzyme deficiency. And there is evidence that this approach may be ineffective or even harmful.

There is, surprise surprise, no clinical research at all on the subject in cats and dogs. Apart from pancreatic insufficiency, in which enzyme supplementation is often effective, the claims made for the use of enzyme supplements are based solely on anecdote, theory, or extrapolation from in vitro research.

9. Coenzyme Q10
Like most dietary supplements, coenzyme Q10, also known as ubiquinone, is recommended for a wide range of apparently unrelated conditions. It is recommended in humans for cardiovascular disease, Alzheimer’s disease, migraines, diabetes, and many others, as well as a general tonic and, of course, the inevitable “boosting” of the immune system. In dogs and cats it has primarily been recommended for treatment or prevention of heart disease and age-related cognitive dysfunction.

There is controversy about many of the recommended uses in humans, with mixed and generally low-quality clinical trial evidence for most uses. And, as you will no doubt have anticipated by now, there is virtually no reliable research on its use in pets. One small experimental study failed to find evidence of decreased Coenzyme Q10 levels in dogs with congestive heart failure. There appear to be no clinical trials for any specific indication, and the recommendations for this supplement are again based entirely on theory, anecdote, and pre-clinical research or clinical research conducted in humans.

10. Azodyl
Azodyl is a proprietary mixture of probiotic organisms and prebiotics (substances intended to promote the growth of supposedly beneficial gastrointestinal bacteria) that is marketed for the treatment of kidney failure in dogs and cats. The theoretical argument advanced to support its use is “enteric dialysis,” the idea that populating the gastrointestinal tract with bacteria that breakdown some of the nitrogenous wastes the kidneys normally remove from the body can lower the levels of these substances and improve clinical symptoms of renal failure. While this idea is not inherently unreasonable, it does suffer from the weakness of other probiotic therapies in that it requires relatively small additional to the gastrointestinal flora to have significant systemic physiologic effects, which may or may not actually be possible. In any case, it is not a concept that has been validated in practice.

A single pilot clinical trial of the product in humans, sponsored by the manufacturer, has been published. This identified statistically significant changes in one out of three laboratory measures and in a subjective assessment of clinical symptoms. An unblinded, uncontrolled case series in 7 cats reported small changes in laboratory values in 6 of the subjects. And similar small studies in vitro and in rats and miniature pigs, again all supported by the manufacturer, have reported some positive changes in some measures of kidney disease.

Overall, the theory is possible but of uncertain plausibility in the real world, and the clinical evidence is limited and highly vulnerable to bias in terms of methods and funding source. 

Bottom Line
So to answer the original question, do these popular supplements work? Well, glucosamine almost certainly does not, and the case for multivitamins and digestive enzymes are extremely weak. Fish oil likely does have small benefit for allergies, and no definitive conclusion can be made concerning arthritis, though the early veterinary trials haven’t been promising. Probiotics are a promising avenue for research, and there is reasonable evidence for some benefit in acute idiopathic diarrhea, but overall they are really not ready for prime time. Lysine, SAM-e, Milk Thistle, and Coenzyme Q10 all have reasonable theoretical foundations based on preclinical research, and none have adequate clinical evidence to draw any firm conclusions.

So should veterinarians and pet owners use these products? The decision whether or not to employ a particular medical intervention is always a matter of balancing the urgency of acting with the risks and benefits of the therapy, and always in the context of the limitations on the available information. In cases where the therapy is very unlikely to provide a benefit, such as glucosamine, there is really no rational argument for its use even if it is harmless, and the resources wasted on such treatments could better be spent on more plausible therapies or research to find better treatments.

In cases where there is a plausible theoretical rationale but inadequate clinical evidence to make a firm conclusion, I am personally reluctant to recommend using such supplements because in the face of such uncertainty we are as likely to do harm as good. For example, Milk Thistle and the combination SAM-e and Milk Thistle products seem to induce loss of appetite in cats and dogs fairly frequently in my experience, and they are usually given to patients who are pretty sick and already taking many other medications. So in the absence of stronger evidence of benefit it seems imprudent to use them routinely. However, in urgent cases where there is no validated therapy and the clinical circumstances are dire, I can’t fault anyone for grasping at straws, and I have certainly done so myself.

And, of course, if there is a sound theoretical rational and some reasonable clinical evidence, as in the case of fish oils for allergies and probiotics for acute uncomplicated diarrhea, use of such supplements seems perfectly reasonable. We must be careful not to let the perfect become the enemy of the good, and in veterinary medicine where the quantity and quality of the research evidence will always be less than optimal, we are justified in trying out things that are reasonable but unproven if the clinical circumstances warrant it.

Of course, the marketing used to promote these supplements goes well beyond anything justified by real scientific evidence and is almost universally untrustworthy. Likewise, the testimonials and anecdotes about their effects, whether from patients, pet owners, veterinarians, or Nobel Laureates, are all just stories with almost no probative value. And since most good ideas in medicine ultimately fail to become real, effective clinical therapies, it is likely that many even of the more plausible of these products will turn out not to be useful or to have unknown risks. Without adequate supporting evidence and without effective quality control, regulation, and post-market surveillance, we can never be sure we are helping and not harming our patients by using them.

However, it is also possible that some of these products will survive the rigors of real scientific investigation, if they are ever subjected to them, and will turn out to be truly useful therapies. And in the meantime, it may be reasonable to use some of them if the existing evidence and clinical need of the particular case are sufficient to justify doing so.

Posted in Herbs and Supplements | 20 Comments

Evolution Diet Update: Selling Food with Fraud

Posted on May 11, 2011 by skeptvet

Early on in the writing of this blog, I posted an article and Evolution Diet, yet another “natural diet” promoted through fallacies, half-truths, and outright lies. I pointed out at the time that the CEO of the company selling this diet, Eric Weisman, had dubious, likely fraudulent academic credentials, a wildly irrational philosophy about health and disease, and a pretty paranoid vision of mainstream medicine. That was about as far as my investigative journalism went. However, a reader has brought to my attention a few additional facts about Mr. Weisman that do seem relevant for anyone trying to evaluate the truth of his claims about the diet.

Mr. Weisman was apparently licensed as a chiropractor in the state of Minnesota in 1979. He was then subsequently investigated and reprimanded multiple times between 1982 and 2002, when his license was finally revoked. Here’s a summary of the series of disciplinary actions and a small sample of the actions that led to them.*

a. Respondent was licensed by the Board on October 16, 1979. On January 18, 1982, the Board issued a consent order concerning Respondent in which Respondent was reprimanded and placed on probation for one year, from January 15, 1982 until January14, 1983. The January 18, 1982 Order included a requirement that Respondent cease to use any advertisement, office designation, or patient informational material that contained any statement or representation from which it might reasonably be inferred that Respondent possessed special qualifications in one or more areas of chiropractic practice, including “holistic chiropractor,” “holistic practitioner,” “M.T.” and “workmen’s compensation specialist,” and/or that Respondent had an ability to cure patients or necessarily make them well.

b. On July 1, 1986, the Board issued a second consent order concerning Respondent whereby Respondent was censured and again placed on probation for one year. The July 1, 1986 Order included, but was not limited to, provisions requiring Respondent to provide only necessary services to patients, to post and display a listing of services, goods and procedures with the current fee for each, and to maintain complete, accurate, current, legible, and readily retrievable records on every patient.

c. On June 18, 1987, the Board issued a third consent order concerning Respondent that, in part, reissued provisions of the July 1, 1986 Order and placed Respondent on probation. The terms, conditions and restrictions of the June 18, 1987 Order remained in effect until July 17, 1997.

d. On July 17, 1997, the Board issued a stipulation and order based on Respondent’s unprofessional conduct and numerous violations of chiropractic statutes and rules (“1997 Order”). Respondent’s violations included, but were not limited to, the following:

            1. Respondent has practiced beyond the scope of his chiropractor’s license by performing chiropractic on andotherwise treating animals. Respondent has also advertised that he performs chiropractic on animals.

            2. Respondent has used numerous advertisements that are unprofessional, misleading, indicate that Respondent guarantees a cure and/or fail to identify Respondent as a chiropractor, including: . . .Numerous advertisements in which Respondent represents that he “guarantees” results or has the “guaranteed fastest, finest treatment available.”

e. The 1997 Order placed Respondent on probation for a minimum of five years….

f. On September 16, 1999, the Board issued a supplemental stipulation and order (“1999 Supplemental Order”), based, in part, on Respondent’s failure to comply with the community service requirement of his 1997 Order… The 1999 Supplemental Order also extended Respondent’s period of probation to three years from the date of the 1999 Supplemental Order and added a requirement that the Board’s approval or disapproval of Respondent’s proposed advertising….

The misconduct that is the subject of this proceeding is particularly egregious.

Respondent falsely held himself out as qualified and authorized to provide an “emergency service” for both humans and animals suffering from life-threatening conditions, claiming that his treatments save “money” or “sometimes a life.” In addition,

Respondent falsely claimed to have “treatment programs” that could “cure” certain forms of heart disease, cancer, diabetes, kidney failure and other conditions. Such advertising preys on vulnerable people and shows that Respondent poses a serious danger to the public.

Respondent has also flagrantly violated the 1997 Order. Despite stipulating to and thus being clearly aware of its terms, Respondent violated five separate provisions of the 1997 Order on multiple occasions. Placing conditions on Respondent’s license was, obviously, not sufficient to prevent his further acts of misconduct.

Taking into account Respondent’s extensive disciplinary history, his failure or inability to rehabilitate himself and his serious misconduct demonstrated by the record in this matter, the Board has concluded that revocation of Respondent’s license is warranted and is necessary to protect the public.

On top of the sanctions from the Board of Chiropractic, Mr. Weisman was also accused of practicing veterinary medicine without a license and sanctioned by the court for this. The stipulation of the finding against him include a number directly related to the Evolution Diet he is still selling on the internet with all the same claims and false credentials, apparently in violation of this court order.

The order specifically forbids Mr. Weisman from making any claims related to preventing or treating disease in animals, including mentioning the “Evolution Diet Plan” by name. He is also forbidden from making any advertising claims that are “untruthful, misleading, or not substantiated by competent and reliable scientific evidence…” It appears Mr. Weisman and his Evolution Diet are yet another example of the failure of government regulation to effectively suppress even the most egregious and dishonest forms of quackery.

While I generally prefer to focus on the evidence and plausibility of particular claims rather than the people behind them, there can be no question in this case that the persistent and proven fraud Mr. Weisman has engaged in are relevant to any judgment about the product he is selling. If ever there were someone from whom one shouldn’t buy water in the desert, much less pet food, it is this man.

*http://www.mn-chiroboard.state.mn.us/Orders/SO%20Weisman%20Eric%20H%2097%2007%2017.pdf

http://www.mn-chiroboard.state.mn.us/Orders/SO%20Weisman%20Eric%20Revocation%20Order%2002%2011%2005.pdf

http://www.mn-chiroboard.state.mn.us/Orders/SO%20Weisman%20Eric%20H%2099%2009%2016.pdf

http://www.vetmed.state.mn.us/portals/22/weisman.pdf

http://www.oah.state.mn.us/aljBase/602015383.FDG.htm

Posted in Nutrition | 11 Comments

Behavior, Expectation, and the Meaning of “Effective”

Posted on May 6, 2011 by skeptvet

This is a guest post from an author who I hope will become a regular contributer. I’ll let her introduce herself:

“Kyzyl is a Ph.D. candidate in biology at a public university on the west coast and a member of the Association of Pet Dog Trainers.  She has been involved in dog training since childhood and participates in several dog sports including nose work, agility, rally, obedience, and herding with her border collie.”

Recently, I received a call from a woman who had adopted a pit bull mix puppy several months earlier for help with the dog’s many developing behavior problems which were driving the woman quite batty.  The puppy, Ziggy (not her real name), exhibited the typical “cute” puppy behaviors of jumping up and mouthing for attention, which now at 4.5 months old and 35 pounds, had become potentially dangerous for the woman’s elderly mother.  In addition, Ziggy had developed a taste for her mother’s lunch, taken right off her plate, and would leave ‘surprises’ in the form of feces and urine in different rooms of the house. 

I listened to her concerns with the dog over the phone, reassured her that these were all solvable problems, and talked about management and training plans.  When I showed up at her home two days later, the first thing she said to me was, “I think that Ziggy must have overheard our conversation on the phone, because ever since we talked, she hasn’t had any accidents and has been much more cooperative! I’m so relieved!”  I explained to her that dogs were incredibly sensitive to our moods and body language, and just the expectation that help was coming was probably enough to make her, and hence the dog, relax and start getting along a bit better.

Now imagine the same scenario, except when scheduling the appointment I had told Ziggy’s owner to give her a certain homeopathic remedy that would start to relieve stress and help cure behavior problems along with management and training.  If the same result occurred, what would have the improvement been attributed to: the owner’s expectation of relief and the dog’s response to this change in her demeanor, or the action of the homeopathic ‘cure?’

Not long ago, Ziggy’s behavior would have been attributed to her being ‘dominant’ over her family.  Dogs, as dominance theory goes, are nothing more than domesticated wolves in need of a strong leader.  Behavior problems were addressed by making the dog submissive to you and every other member of the family, often by forceful means. The basis of many behavior problems were explained this way, and we know now that dominance theory is wrong.

As the result of scientific study, we know that dogs are not wolves and do not construct strict hierarchical relationships between each other or humans (neither do wild wolves, it turns out).  Today most behavior problems are explained in terms of learning theory, scientific principles derived from systematic study.  A puppy jumps to get attention (not to assert her dominance), and a fearful dog will bark and lunge to keep frightening things away (not as an effort to lead and protect the family). Dogs are now taught alternate, incompatible behaviors to solve problems, and the days of forcing dogs into submission as the result of pseudoscientific dominance theory are, thankfully, coming to an end.

Many trainers and behaviorists have joyfully embraced the modern science of dog behavior and methods of behavior modification based on positive reinforcement because they are more humane, safe, and easier than punitive training techniques often rooted dominance theory. However, some trainers also advocate for decidedly pseudoscientific complementary and alternative medicines as well.  Homeopathy and Bach Flower Essences (BFE), a near-homeopathic preparation, are often recommended for difficult to resolve behaviors such as those associated with fear, separation anxiety, and aggression (Hanson 2006, Wilde 2006).  While these trainers will swear by how effective these treatments are for some of their clients, the treatments find little support in the scientific community.  How can trainers decide what is the best mode of treatment to recommend for difficult behavior problems?

In reality, behaviors are the result of complicated and dynamic brains interacting with complicated, dynamic surroundings.  Great care must be taken to understand and minimize as many confounding factors and biases as possible to systematically study the treatments for behavioral problems.  Having expectations about a treatment outcome allows you to fool yourself into believing that a treatment is effective far easier, whether you are the owner of a dog with behavior problems or a researcher studying those effects.  For the trainer or researcher, expectations based on seeing improvement first-hand or event timing may allow you to convince yourself that patterns between events exist when in reality they do not. For the owner, the impact of expectation of treatment benefits is part of the placebo effect; a phenomenon where treatment with sugar pills, which have no active ingredient, create improvement in a dog’s symptoms.  Dog owners are often desperate to help their distressed animals or find relief from behaviors that cause them distress, and this desperation can lead to unconsciously inflating positive outcomes. Fooling yourself is extremely easy when studying complicated systems, especially when both parties have vested interests in the outcome.  

There are two methods in well-designed clinical trials that control for the effects of bias and the placebo effect: placebo-controlled and double-blinding.  Placebo controls consist of using a “sham” treatment with no active ingredient, such as sugar pills or water, in addition to a “real” treatment with the active ingredient being tested.  When neither the doctors nor the patients know who is on which treatment, it is double-blind.    Any difference between the control and treatment groups is likely due to the active ingredient in the treatment being tested, or the treatment is said to have a “specific effect” beyond what is seen with placebo treatment.  This is the definition of effective from the viewpoint of a science: a treatment that has specific, measurable effects beyond that of a placebo.

These are the same standards by which most science-based medical treatments are judged for efficacy, and ideally the standards should also apply to treatments recommended by trainers and behaviorists for behavior problems in pets.  Evidence for  complementary and alternative modalities is often either non-existent or not promising (Overall 2008), and the use of homeopathy and BFE for a variety of behavior problems are not exceptions.  The few double-blind, placebo-controlled trials which have been conducted using homeopathy to treat fear showed no difference between homeopathic preparations and placebo (Cracknell and Mills 2008), even when their owners knew their dogs were receiving the placebo (Cracknell and Mills 2011).  More well-designed trials on homeopathy use for treating fear, anxiety, and stress in people have had similarly negative results (Walach et al. 2001, Halberstein et al. 2007).  Additionally, systematic reviews of many trials using homeopathy and BFE for treating behavior problems have found no meaningful effects of these treatments beyond placebo (Thaler et al. 2009). 

Why is there inconsistency in recommending science-based behavior modification and unsupported complementary and alternative remedies? According to many professionals, these treatments are effective because dogs and owners benefit from a decrease in the unwanted behavior.  Although improvements, apparent or real, are almost certainly a result of the placebo or other non-specific effects, in many cases they make owners feel like they are doing everything they can for their struggling pets. 

While some trainers and behaviorists believe that CAM treatments represent truly effective, superior alternatives to ‘traditional’ medicine, I believe many more doubt their benefits but want to help in any way they believe is safe and might be effective.  For them, recommending something with no side effects that could produce improvement (regardless of the mechanism) to an owner who may refuse pharmaceutical intervention and wants treatment beyond behavioral modification is a reasonable decision.

However, the recommendation to use a CAM treatment has consequences.   First, knowingly recommending placebos for treating unwanted behavior is a sticky ethical issue.  Recommending a treatment that has no specific effects to owners without disclosing these facts is deceptive, even if benefits are ultimately gained through non-specific effects.  Deception damages the professionalism of a trainer or behaviorist and certainly leads to a degradation of trust between professional and client. 

Second, there are indirect consequences in recommending CAM remedies.  Many people treat these remedies as truly alternative and will shun traditional medical and behavioral treatments which are demonstrated to be effective, safe, and reliable. This might be especially problematic for behavioral problems for which behavior modification is a difficult and time-consuming endeavor or is not as effective without pharmaceutical intervention (such as severe separation anxiety and compulsive disorder). 

Third, recommending CAM therapies also reinforces the idea that these treatments are part of a legitimate healthcare regiment and will often accept other advice offered regarding healthcare, such as the rejection of vaccines, which have significant impacts on the health and well being of pets.  These consequences of suggesting CAM treatments should be seriously considered before recommending them to clients desperate for a cure.

Trainers are often the first line of professionals contacted when their pet’s behavior problems become too much to bear.  The stakes are high: many dogs are euthanized in the US for severe behavior problems, and many more are surrendered to shelters with the same ultimate result.  Most of these problems can be treated effectively with behavior modification and traditional pharmaceuticals administered by a veterinarian or veterinary behaviorist, and trainers have a responsibility to know about and explain the possible options to distressed owners. We also have a responsibility to advocate treatment plans which have a solid basis in science, treatments that rise to the same definition of effective as treatment for medical conditions.

Cracknell, N.R., and D.S. Mills. 2008. A double-blind placebo-controlled study into the efficacy of a homeopathic remedy for fear of firework noises in the dog (Canis familiaris). Vet. Journal 177, 80–88.

Cracknell, N.R. and D.S. Mills. 2011. An evaluation of owner expectation on apparent treatment effect in a blinded comparison of 2 homeopathic remedies for firework noise sensitivity in dogs. J. Vet. Behavior 6: 21-30.

Halberstein, R., L. DeSantis, A. Sirkin, V. Padron-Fajardo and M. Ojeda-Vaz. 2007. Healing With Bach® Flower Essences: Testing a Complementary Therapy. Comp. Health Practice Review 12: 3.

Hanson, D. 2006. An overview of the Bach Flower Essences. APDT Chronicle of the Dog. March/April issue.

Overall, K.L. and A.E. Dunham. 2009.  Homeopathy and the curse of the scientific mind. Vet. Journal 180: 141-148.

Thaler, K., A. Kaminski, A. Chapman, T. Langley, and G. Gartlehner. 2009. Bach Flower Remedies for psychological problems and pain: a systematic review. BMC Complementary and Alternative Medicine 9:16.

Walach, H., C. Rilling, and U. Engelke. 2001. Efficacy of Bach-flower remedies in test anxiety: A double-blind, placebo-controlled, randomized trial with partial crossover. Anxiety Disorders 15: 359-366.

Wilde, N. 2006. “Ch. 43: Flower Power,”  Help for Your Fearful Dog: A Step-by-Step Guide to Helping Your Dog Conquer His Fears. Phantom Publishing, 1st ed.

Posted in Guest Posts | 8 Comments

Failing to Make their Case through Science, Veterinary Homeopaths Choose to Sue

Posted on May 1, 2011 by skeptvet

I recently discussed in detail the Academy of Veterinary Homeopathy’s (AVH) annual conference, and it’s apparent focus on demonstrating the scientific legitimacy of homeopathy, and I discussed in detail why this attempt was a failure and homeopathy is not compatible with legitimate science by the standards either of science or those of the AVH. The unscientific attitude of homeopaths, including their self-righteous indignation at any criticism of their reasoning and methods, was subsequently emphasized by an attempt to suppress my criticism with the threat of litigation for copyright infringement. I didn’t realize at the time that this is part of a consistent strategy on the part of the AVH to achieve the appearance at least of scientific legitimacy by any means necessary when scientific arguments alone fail.

Due to a relatively recent shift in the membership and attitude of the Registry of Approved Continuing Education (RACE), the group that establishes standards for the continuing education courses veterinarians need to complete to maintain their licenses, RACE approval has been denied for a number of AVH continuing education courses in the last few years. This is perfectly appropriate as the purpose of continuing education requirements is to encourage that high-quality, scientific quality of veterinary medicine is available to clients and their animals.

However, rather than behaving like scientists and working harder to demonstrate the truth of their claims (which, admittedly, I would expect to be unsuccessful given the mountains of evidence already accumulated against these claims) veterinary homeopaths have chosen to pursue political means to get what they can’t get by making their case through the accepted methods of science. The American Holistic Veterinary Medical Association (AHVMA) encourages members to skirt national accreditation standards for continuing education by forming state organizations that are affiliated with state veterinary medical associations, and thus automatically eligible for continuing education credit regardless of the nature of the content. This is a transparent “end run” around the national standards set by RACE.

And now the AVH has gone a step further, filing a lawsuit against the American Association of Veterinary State Boards (AAVSB), the parent organization of RACE. The only details I have been able to find concerning the lawsuit are from the AVH press release, which obviously is not an impartial source of information. But whatever the details of the suit, using the courts as a way to force a professional standards body to accept as legitimate a pseudoscience like homeopathy is clearly inconsistent with the very philosophy of real science. It is also, unfortunately, a savvy political move.

I have written extensively about the relationship of the courts to medical licensing and standards of practice. The hard reality is that the courts are not always as concerned about the scientific truth concerning a practice like homeopathy as they are about issues such as the prerogatives and limitations of government regulatory bodies, fairness of competition in the “marketplace” of medicine, and other non-scientific issues. While it would seem obvious that the RACE is under no obligation to certify as scientifically legitimate a clearly unscientific practice like homeopathy, in reality the  issues of “breach of contract and fraud” cited in the press release may or may not be seen as legitimate, and more important, by the courts.

If this lawsuit succeeds, it will have potentially serious implications for the quality of veterinary medicine. The acceptance of homeopathic continuing education courses as valid for maintaining one’s veterinary license could have a direct impact simply by encouraging the practice of homeopathy, which has never been proven to be an effective therapy for any condition. But this is probably the least significant concern, given that most veterinarians recognize the lack of real evidence to justify using homeopathy, and therefore most don’t use it.

More concerning, however, is the intimidating effect a ruling in favor of the AVH would have on state boards and other organizations which set standards for veterinary medicine. The antitrust lawsuit by chiropractors against the AMA essentially deterred the AMA from officially challenging the legitimacy of any other alternative therapy. A ruling for the AVH could convince AASVB and other organizations that it is not worth it to try and maintain any scientific standards in the face of pressure from veterinarians or clients who believe in unscientific approaches. RACE accreditation for training in psychic animal communication, veterinary astrology, crystal therapy, and so on would be just as reasonable as accreditation for homeopathic education, and just as bad for the quality and reputation of veterinary medicine.

The RACE position against granting legitimacy to the pseudoscience of homeopathy is a refreshing exception to the general lack of rigorous, science-based standards applied to alternative veterinary medical approaches generally by professional and regulatory organizations. If it is undone by the use of litigation, it will be a sad comment on the ability of the veterinary profession to continue to honestly promote itself as a legitimate branch of scientific medicine. And, despite claims by homeopaths, it will be a sad day for our patients and our clients, who will be even more easily sold useless nonsense as if it were legitimate medicine.

Posted in Homeopathy, Law, Regulation, and Politics | 6 Comments

Evidence-Based Medicine Works Better

Posted on April 27, 2011 by skeptvet

There are a lot of theoretical arguments in favor of science-based and evidence-based medicine and against the alternatives of opinion-based, tradition-based, or faith-based medicine, and I have discussed many of these (for example, Medical Cognition, Spiraling Empiricism, the Dunning-Kruger Effect, and a host of reasons why clinical judgment is unreliable). However, the bottom line that I always come back to is that evidence-based medicine works! This is evident from the simple and obvious story of medical history, which illustrates the dramatic and unprecedented improvement in the length and quality of human life that science and its application to sanitation, nutrition, and medicine have brought us. But it is also evident in a more quantifiable way in a new study which found that the adoption of consistent, evidence-based standards of care for hospital patients with heart disease resulted in a marked improvement in both short and long-term survival.

The study was conducted in Sweden and involved a national database that covers almost all hospitals in the country. It included records for over 67,000 patients treated over a 12-year period for a particular kind of abnormal heart rhythm associated with a heart attacked. The study demonstrated that specific evidence-based practices, including surgical procedures and the use of new medications, gradually increased over the course of the study. Along with this, in-hospital complications decreased, and survival improved markedly at 30 days, 1 year, and 12 years after the heart attack. Looked at another way, this translates into an average of almost 3 years longer survival for a patient treated at the end of the study, with more evidence-based methods, than at the beginning of the study.

For all the confidence we have in our judgment and experience, and those of our mentors, and all the optimistic promises made for ideas justified by tradition and anecdote, the bottom line is that the slow, laborious, rigorous process of basing our treatments on ever-changing scientific evidence simply works better.

Posted in General | 1 Comment

Is Surgery Really Necessary for Dogs with Ruptured Cruciate Ligaments

Posted on April 25, 2011 by skeptvet

In a recent article concerning an herbal product used for treatment of a dog with a ruptured cranial cruciate ligament (the equivalent of the “ACL” in humans), I stated, “Surgery is the treatment of choice for a ruptured cruciate ligament. Weight loss, physical therapy, and possibly medications are all helpful and important, but without surgery a large dog will have permanent instability in the knee and will develop progressive arthritis.” One of my regular readers challenged this statement and referred to evidence in humans suggesting that surgical therapy was no better than non-surgical therapy in treating this disease. This stimulated me to look into my assumption that surgery was superior to medical management for large dogs and see whether or not the evidence supports this claim.

Following the usual approach I take in evaluating a proposed therapy, I will look at the plausibility of the intervention first. A great deal has been written about the biomechanics of the canine knee and all the factors that may play a role in cruciate ligament ruptures (e.g. 1, 2, 3, 4, 5, 6, 7, 8). The bottom line of all this is that ruptures of the ligament are caused by multiple interacting factors including breed (and hence genetic influences), size, the structure of the canine knee, and activity. The various surgical procedures recommended for this disease are all rational and plausible based on a detailed understanding of the basic biomechanics of the disease.

There have also been many studies looking at the effect of various surgical procedures in animal models of the disease, usually laboratory dogs with ligaments that have been deliberately damaged. While this sort of model does not replicate all the features of naturally occurring disease, it can provide some clue as to whether the surgical therapies are likely to be effective. These sorts of studies, often used as models for arthritis in general, show clearly that severe joint disease and marked dysfunction results over time without surgical treatment of a ruptured cruciate ligament (e.g. 9, 10, 11, 12, 13, 14, 15)

There is extensive clinical research in humans concerning whether surgical repair of cruciate ligament rupture is necessary. I am quite skeptical of the applicability of this research to the same question in dogs since the biomechanics of the canine knee are quite different from those of the human knee. Also, conservative management for humans includes exercise restriction, physical therapy, and often immobilization of the knee with a brace, all of which are challenging and not often used in dogs with ruptured cruciate ligaments. However, the basic anatomy and pathophysiology of arthritis are quite similar, so research in humans may have some value in answering the question for dogs.

The results of clinical trials in humans are mixed. One Cochrane Review examining older surgical techniques found they were generally superior to conservative management. Some studies have found no advantage to surgical management, but these are not large or methodologically robust trials. It appears that both conservative and surgical management can have good outcomes, but the differences depend on the patient population (age, nature of injury, activity level, compliance with treatment, etc) and the specific therapy employed, so not incontrovertible conclusion can be made as to whether surgery or conservative management is superior overall.

There are a many studies looking at the outcome of surgical treatment of cruciate ruptures in dogs. Overall, they find good outcomes in the range of 70-80% or more of patients returning to normal or near normal function (e.g. 16, 17, 18, 19). Comparisons of different methods of surgical repair do not support the clear superiority of one method. However, there are few studies directly comparing surgical and non-surgical treatment in dogs. The best of these, published in 1984, compared outcomes of non-surgical treatment in dogs weighing more or less than 15kg (about 30lbs). For the dogs over 15kg, only 19% were normal (7%) or improved (12%)  years after their injury, and all had clear evidence of severe arthritis in the affected knee. For dogs weighing less than 15kg, almost 86% were normal (75%) or improved (11), and while all of these had evidence of moderate arthritis, it did not seem to affect the function of most of these dogs. Other less rigorous studies have the same general findings (20, Paatsama S: Ligament Injuries of the Canine Stifle Joint: A Clinical and Experimental Study. Master’s thesis, Helsinki, 1952) 

Conclusion
As is almost always the case, the evidence is not of the highest possible quality or unequivocal, but this does not exempt us from having to draw conclusions and make recommendations to our clients. My interpretation of the available evidence is that overall, cruciate ligament disease causes significant arthritis and loss of function when untreated. For most dogs under 15kg, conservative management (primarily restricted activity for 3-6 weeks, achieving and maintaining and appropriate body weight, and possibly physical therapy and pain medication) can achieve acceptable comfort and function. In larger dogs, significant arthritis is inevitable and dysfunction is extremely likely without surgical treatment. No single surgical technique is clearly superior, so the choice of specific surgery should be determined by the judgment of the individual surgeon and the needs of the owner.

Posted in Science-Based Veterinary Medicine | 226 Comments

Milk Thistle in Dogs and Cats

Posted on April 20, 2011 by skeptvet

Milk thistle is an herbal product that is widely recommended and used by veterinarians. Like glucosamine, it is a supplement which has leapt over the gap between alternative and conventional medicine. Unfortunately, like glucosamine, this acceptance has come about on the basis of pretty weak evidence.

The active ingredient is a cluster of compounds called silymarin. There has been extensive in vitro research on silymarin, and it has a wide range of potentially useful effects. It appears to interfere with pro-inflammatory chemicals, functions as an anti-oxidant, and may interfere with the metabolism of some chemicals into toxic compounds in the liver. It also has some activity which could be potentially harmful, including interfering with the metabolism of a number of drugs and stimulating the effects of hormones like estrogen. As usual, these laboratory findings indicate the possibility of useful clinical effects, but most compounds that have these sorts of potentially useful effects in test tubes don’t work out to be good medicines.

The primary uses of silymarin in humans are to protect against or treat liver damage from toxins and infectious diseases, to improve the condition of diabetics, and to protect the kidneys from toxins. Some of these uses are based on traditional folklore, but as usual there are many traditional uses no longer recommended and for which there is not yet scientific support, including disease of the spleen, uterine disease, malaria treatment, appetite stimulation, stimulation of lactation, and others. In dogs and cats the primary use of for non-specific “support” of the liver regardless of the specific disease.

In humans, clinical trial evidence is mixed. A couple of studies have suggested it reduces insulin resistance in diabetic and may lower blood lipid levels. A Cochrane review of 13 studies including 915 people “could not demonstrate significant effects of milk thistle on mortality or complications of liver disease in patients with alcoholic and/or hepatitis B or C liver disease.” High quality trials were negative, and low quality trials suggested a benefit.

Very little research exists in dogs and cats. A small study of 20 cats given acetaminophen, a known liver toxin, found that those given a single oral dose of silymarin did not show the elevation of liver enzyme levels seen in those not given the compound. A similar study of dogs found some differences in elevations of kidney values between those that got silymarin and those that didn’t following exposure to a kidney toxin, though there was not a completely consistent pattern.

A study done in 1978 showed that dogs given a toxic mushroom compound orally and then given silymarin intravenously did not show the increase in liver values that was seen in control dogs. Another in 1984 found that 30% of the control dogs died whereas none of the dogs given IV silymarin along with the mushroom toxin died, and the livers from the treated dogs did not appear damaged by the toxin.

As far as risks, there appear to be few. Nausea, diarrhea, and other gastrointestinal effects are sometimes seen, and allergic reactions have been reported in humans.

So overall, the in vitro and laboratory animal evidence indicates it is plausible that milk thistle extract might have beneficial effects, though harmful effects in some situations could be expected as well. In humans, the clinical trials show weak evidence for benefit in diabetics and inconsistent but generally negative evidence for benefit in alcoholic or hepatitis-associated liver disease. Very little experimental, and apparently no high quality or controlled clinical research exists in dogs and cats. What there is suggests a benefit is possible. But we must bear in mind that preliminary, low-quality trials of milk thistle in humans looked promising but were not supported by subsequent better quality trials.

A clinical trial comparing animals with naturally occurring liver disease treated identically except for receiving either milk thistle or a placebo would be quite useful. In the meantime, use of the compound is not unreasonable given the suggestive low-level evidence, but it is not much more than a hopeful shot in the dark at this point.

Posted in Herbs and Supplements | 29 Comments

Chamomile Tea for Arthritis in Dogs

Posted on April 19, 2011 by skeptvet

I recently had a case which illustrates alternative therapies commonly present themselves in my daily practice. A patient, an older large breed dog, came in for an annual exam. He was in good general health but moderately overweight, and the only complaint was gradually progressive weakness in his hind legs. This is common in large older dogs and is often due to arthritis in the spine or hind legs. In this case, the patient had been diagnosed with a ruptured cranial cruciate ligament years before. At that time he was unable to use the leg and surgery had been recommended.

Surgery is the treatment of choice for a ruptured cruciate ligament. Weight loss, physical therapy, and possibly medications are all helpful and important, but without surgery a large dog will have permanent instability in the knee and will develop progressive arthritis. The acute pain of a recent ligament rupture will change to the nagging, chronic pain of degenerative joint disease, and the patient will learn to compensate for the disability, but the joint will not be fully functional or comfortable without repair.

There are a variety of surgical procedures available, and the evidence is not definitive as to which is the best, though most work well. Sometimes surgery is not possible because of the cost or other conditions the patient may have, but in this case surgery was not performed because of a misconception generated in part by the use of an alternative herbal remedy.

A veterinarian who practices primarily alternative therapies (mostly TCM and acupuncture but an assortment of others as well) had recommended Sleepytime herbal tea for treatment of the dog’s presumed arthritis. The main ingredient, chamomile flowers, is sometimes recommended for reducing anxiety, soothing an upset stomach or skin ailments, though like most herbal products one can find a recommendation for using it in dozens of unrelated conditions. It is reported to have anti-inflammatory properties and is one of a number of herbal ingredients in some products marketed for arthritis in dogs.

So what’s the evidence for using chamomile for arthritis? None that I can find. The Desktop Guide to Complementary and Alternative Medicine: An Evidence-Based Approach states:

There is little convincing evidence to support the therapeutic effectiveness of chamomile extracts. Encouraging evidence is emerging for a specific combination preparation in patients with functional dyspepsia. Given the risk of allergic reactions and the few rigorous clinical trials that have been conducted, it is not entirely clear whether the potential benefits outweigh the possible risks.

Neither this resource, nor PubMed, nor the Natural Medicine Comprehensive Database list any clinical trials in any species for chamomile as a treatment for arthritis. There are a couple of in vitro studies which suggest it might interfere with some enzymes that are involved in inflammation, but that is a far cry from proof of any clinical benefit in dogs with degenerative joint disease.

Are there any risks? Probably few. I happen to really like Sleepytime tea for the taste, and it has been a popular herbal tea for decades. It certainly is unlikely to be a significant health risk when brewed and drunk in the ordinary way. Severe allergic reactions to chamomile extracts have been reported in humans, but these are not apparently common, and there is no data on whether this is an issue for dogs.

So once again, the remedy itself is probably harmless and probably useless. Then what’s the problem? Well, the owners of this dog believed it helped their pet. The lameness gradually decreased over weeks to months of time, as it would be expected to do without any treatment at all. The owners took this as evidence the therapy was working and that surgery or real medical therapy was not needed. So now the dog has progressive arthritis and decreased use of one of its legs due to a lack of appropriate treatment for a very treatable problem. And this is largely because of the owners misperception and misplaced faith in a useless therapy. Such is often the way seemingly benign interventions like this can do harm.

Posted in Herbs and Supplements | 10 Comments