I have been covering the application of the American College of Veterinary Botanical Medicine (ACVBM) for recognition as a specialty in several posts throughout the year (1, 2). My conclusion is that this recognition is not justified for several reasons:
- There is very little high-quality or reliable scientific evidence to support the use of herbal products in veterinary patients.
- Herbal prescribing is dominated by Chinese Medicine, Ayurveda, and other unscientific folk belief systems, and those proponents who take a more scientific approach are a small minority generally unwilling to reject the claims or methods of alternative herbal medicine.
- Herbal products are unregulated, inconsistent and unpredictable in their chemical composition, frequently contaminated with toxins or even undisclosed pharmaceutical drugs, and almost none have been properly tested for safety or efficacy. There is ample evidence of serious harm to human patients from herbal products. The ACVBM supports industry self-regulation rather than the kind of government oversight accepted as necessary for pharmaceutical medicines without any sound reason for doing so.
- The majority of the leadership of the ACVBM are dedicated proponents of alternative medicine, not only for herbal products but homeopathy, acupuncture, energy medicine, and many other unproven or pseudoscientific practices. Many have said clear and troubling things that display a contempt for science and science-based medicine and a desire to use the appearance of scientific methods to gain acceptance for alternative practices. This makes it very likely that approval of the ACVBM as a specialty board would serve as a Trojan horse for the legitimization of other alternative therapies.
- The potential of herbal medicines would be better explored from a rigorously scientific approach involving specialists in pharmacology, toxicology, nutrition, epidemiology, and other existing medical specialties.
The ACVBM has just released a revised version of their application. While I haven’t exhaustively compared this to previous versions, a couple of sections caught my interest because they directly address some of my concerns and also because they further illustrate the perspective of the group regarding the key issues of science and evidence.
Some material has been added to emphasize why the ACVBM should be a separate specialty college rather than investigating herbal treatments under the auspices of existing specialties.
Veterinary botanical medicine is a distinct discipline that differs in substance, methodology and philosophy from conventional veterinary medicine.
I will briefly comment on some of the specific arguments made to justify this claim.
While many conventional drugs are derived from plants, a veterinarian who prescribes botanical medicine is using whole herbs in preference to isolated active constituents. The whole herb or extracted herb is complex, containing hundreds of constituents that have complex actions…Veterinary herbalists are aware of differences in plant chemistry that may result from the plant’s origins.
The first half of this statement is certainly correct. Whole plants and herbal combinations are chemically very complex. This is usually identified as an advantage (as will be seen below), but it is actually one of the reasons herbal medicine is problematic. The consistency, efficacy, and safety of such complex combinations with variable ratios of different compounds that depend on multiple factors makes it very difficult to accurately predict the effects of such remedies. Herbalists claim to have specialized expertise in doing so, but when investigated these claims amount only to a belief that personal clinical experience or folk medicine traditions are reliable information, which is manifestly untrue more often than not.
That the whole plant is more therapeutic than a constituent is a fundamental principle of botanical medicine supported by research.
Well, the first half of this statement is true as well, but the second half is not. Herbalists believe whole plants to be better than isolated compounds (also known as medicine), but they have in no way proven this through research. There are studies that show combinations of plant chemicals to be more effective in some uses than each used separately. Most of this is experimental research rather than clinical studies, which is important since the use of such combinations in actual patients is significantly more complex and uncertain.
The idea that combinations of chemicals may have greater effect than the same chemicals used separately is not all that surprising or unique to herbal medicine. Combination regimes of chemotherapy are often more effective than single-drug treatment. And some infections require multiple antibiotics given together to address all the pathogenic organisms involved. However, this does not prove some kind of general principle that combinations are always safer or more effective than single agents. It is equally likely that combinations may have greater toxicity (as if often the case when conventional medicines are used in combination), and sometimes they may interfere with one another. The fact that the compounds occur naturally together in a plant is no reason to imagine we can assume they are better as medicine when given together.
The principle of synergism may turn out to be true in many, some, or only few cases, but these need to be validated through clinical research. The assumption that this is true stems from pre-scientific folk beliefs about “natural” remedies or religious notions that God has provided for the needs of human beings by packaging remedies for our ills in nature. These beliefs have not been validated scientifically despite the claims to the contrary. Many interesting hypotheses are advanced in the application for how herbal combinations could potentially be more effective or safer than isolated compounds, but these are just hypotheses, not the established fact claimed in the document.
The application goes on to respond to concerns about the use of folk myth and pre-scientific tradition rather than science in the use of herbal remedies. The ACVBM is clearly trying to mitigate the impression that herbalists rely primarily on “traditional knowledge” rather than science in their practice.
The ACVBM differentiates themselves by interest in the rich knowledge base of traditional botanical medicine use and ethnobotany combined with modern scientific, chemical, toxicological, pharmacological clinical application and research in a practice that could be appropriately termed rationale phytotherapy to distinguish from colleagues who may only embrace traditional findings or who may eschew scientific findings. This is an evidence-based system that encourages in vitro and in vivo studies to explain mechanisms of action, pathophysiology, pharmacokinetics and bioavailability as well as efficacy of botanical medicines.
This is the application of plant based medicine (supported by science and/or traditional use) to conventional diagnosis, multiple diagnoses and complex cases and to address individual signs and problem lists; or for prevention of disease by protecting organ health and /or optimizing animal health through actions not available with conventional drugs.
I certainly believe that the best hope for making effective use of the potential in plant compounds as medicines is in a strong scientific approach, one that views traditional use only as a weak foundation for hypotheses to test, not as a sufficient basis for clinical practice. I am, however, not convinced that the ACVBM as a whole truly embraces this view. I have investigated the public statements are claims of the members of the Organizing Committee in detail, and I have followed many of them for years. A couple seems genuinely interested in bringing scientific rigor to the field. Most, however, have been quite consistent in expressing the view that science is useful only when is supports their beliefs, derived primarily from personal experience and tradition, and that scientific invalidation of anything they “know” already is nearly impossible. Science is more of a marketing tool, to convince the skeptics, not a path to testing and questioning their own views rigorously and sincerely. There are hints of this even in this document, despite efforts to suggest agreement with the view than science is necessary and tradition merely a jumping-off point.
Veterinarians using botanical medicine have a patient centered approach, whereby the botanical medicines are selected based on the individual signs and pathophysiology as well as the diagnosis. So that two dogs with diabetes for example, may be treated with two different sets of botanical medicines.
What they don’t say here is that this “individualization” is not based on scientifically established knowledge but folk tradition, personal experience, and gut feelings.
The document also discusses various sources of information in detail, with an obvious effort to rationalize the role of tradition and personal experience in the absence of significant reliable scientific evidence. This is not inherently mistaken, since the same sources of information are used in conventional medicine, and we always have to balance the availability of information against its reliability. Personal experience is easy to find but highly unreliable. Consistent, high-quality clinical research is a lot better but a lot harder to come by.
Traditional use-
The bewildering variety of ethnoveterinary practices, ethnobotanical uses and folk practices around the world coupled with confounding aspects of cultural, placebo and other non-specific effects make reliable conclusions from any one tradition difficult. Frequently however, traditional use informs research and pharmacological activity is often found to be closely correlated. There are recurring themes in traditional medicine and persistent therapeutic approaches consistent with the use of “archetypal” chemical groups within plants.
Contrary to the implications here, traditional folk practices do not consistently or accurately predict the pharmacology or clinical effects of plant chemicals. The vast majority of traditional herbal uses have not been tested. Many of these, however, make absolutely no sense and so are unlikely to be a productive foundation for research. The idea of sympathetic magic, that if things which have superficial similarities these can predict deeper connections with therapeutic value, is clearly nonsense. Plants that may resemble a penis in some people’s eyes do not consistently turn out to be aphrodisiacs. Plants that are wrinkled like the brain or lobed like the lungs or that otherwise have some subjective superficial similarity to an organ in the body do not turn out to be plants with medical value for treating diseases of those organs, despite many folk medicine traditions holding this belief.
And systems which are arbitrary and unconnected with scientific reality are not good predictors of the medical value of plants used in those systems. Chinese medicine, for example, emphasizes the balance of imaginary forces, such as Heat, Wind, Damp, etc. Other systems, such as Western Humoral Medicine and the related Indian Ayurvedic approach, also emphasize balancing various forces to achieve or restore health. However, the forces involved are imaginary constructs that don’t correlate to physical reality. Most of the specific practices based on these theories don’t work, which is why thousands of years of using these ideas to guide medicine accomplished almost nothing in terms of improving health or fighting disease. The fact that the systems have similar concepts doesn’t make relying on the concepts, or the interventions derived from them, any more effective.
Collective clinical experience over decades-
There is also the clinical experience of veterinary practitioners to consider- thousands of educated veterinary practitioners worldwide prescribe herbal medicines in their work. This has advantages of being in a modern veterinary context. Veterinary practitioners of botanical medicine have written texts and taught other veterinarians to achieve repeatable results within the botanical framework.
Clinical experience is often the basis for treatment decisions in medicine. It is widely recognized in science-based medicine to be a shaky and unreliable foundation for decision-making compared to controlled scientific research, but often we lack research evidence to fully inform all the care we give. Unfortunately, we all tend to rely too much on experience, and it is common for clinicians to continue employing practices that seem effective to them based on their experience even when better scientific evidence has shown them not to work.
As a community, alternative medicine proponents are even less amenable to abandoning disproven methods than the science-based medicine community. The reverence for tradition and the relatively greater lack of research evidence to support alternative practices leads to a greater trust in experience even than conventional clinicians. Certainly, there are individuals who are committed to a rigorously scientific approach to herbal medicine. However, many of the leaders of the ACVBM have repeated expressed the view that science is predominantly a way of proving to others what they already know to be true from their own experience, rather than honestly testing their beliefs. Science does not yet support the claim here that herbal practitioners can achieve “repeatable results,” and unfortunately it is unlikely that the leaders of this group will change their minds and give up practices they believe to be effective even if good research evidence shows this.
The available published literature on phytochemistry and preclinical pharmacology (that frequently involve animal models exploiting mice, rats, rabbits and less so cats and dogs) of plant extracts is prolific. There are peer-reviewed journals devoted to the subject. Researchers have no doubt that nature is still the preeminent synthetic chemist and that in plants there are infinite reserves of fascinating constituents with actual and potential effects on health and disease. As such information accumulates it is often easier to better understand traditional uses of plants.
They do not however provide confirmation of a clinical effect; experience in practice is that the effect of the whole plant is rarely predicated on the effects of its parts. However such studies help to provide a rationale for the mechanisms of action of a herb.
For once, I agree completely. The bulk of research evidence concerning plant compounds is pre-clinical basic lab research. There is a lot that suggests these compounds may have significant medical value when used in the right way for the right problems. However, this kind of research does not justify the extensive use of herbal remedies in actual patients, which is precisely what the ACVBM is not only recommending but suggesting should be viewed as a legitimate medical specialty.
There are few well conducted placebo controlled double blind clinical trials on the effects of herbs in veterinary medicine. These are expensive to conduct and present methodological and logistical challenges. However, the evidence is accumulating in human medicine and rising in veterinary medicine.
Again, first half true, second half merely opinion. The overwhelming majority of the medical use of herbs in humans has not been proven in clinical trials to be safe or effective. Even some of the most widely used and promising herbal interventions that have been studied for decades, such as St. John’s Wort, have failed to show benefits that outweigh the risks. There is no repeatable, high-quality clinical trial evidence for any herbal prescribing in veterinary species. Such research must be conducted before we can even know if herbal medicine is useful, much less before we can call it a medical specialty.
No single source can absolutely confirm that herbs are a rational treatment strategy.Therefore, it is appreciated that herbs have been dismissed by many in the profession as the refuge of the uncritical. However, when all the sources of information come together and are integrated with pharmacological insights, something important happens; unique treatment strategies for treating notoriously difficult clinical problems become possible and the desire of the ACVBM is for animals to benefit from the efforts of this group to further develop the field.
Pure faith here. All of the evidence sources taken together suggest that some herbal products might be useful for some conditions in some cases, and these are worth testing. Nothing here shows convincingly that any herbal practice is dramatically effective or that herbal medicine has advanced to the point where it should be a medical specialty on a par with oncology, internal medicine, or other specialty areas in which the level of research evidence is dramatically higher.
The section on “philosophy” is especially interesting. A number of elements have been omitted, including the notion of non-physical spiritual or “energetic” forces involved in health and disease, which many of the leaders of the ACVBM have promoted elsewhere as integral to their practice. However, this section still shows some of the beliefs and assumptions behind herbalism which are problematic from the point of view of science.
The universal role of plants in the treatment of disease is exemplified by their use in all the major systems of traditional medicine and ethnomedicine irrespective of their underlying philosophical premise.
This may or may not be true, but it is irrelevant and an example of the appeal to popularity fallacy. Because something is widely practiced or believed has no bearing on whether it is true or should be accepted or adopted. The majority of pre-scientific folk medicine traditions also include specific religious or spiritual beliefs and practices, but that doesn’t mean these should be incorporated into science-based veterinary medicine.
The practitioner of botanical medicine regards the whole formula or whole extract as the “active ”component” in the therapeutic context.
The concept of polyvalent or multifaceted activity of the medicine is central to botanical medicine
-in the context of the advantage of chemical complexity -and even a single herbal extract is a natural multi agent medicine that can simultaneously target a range of desirable pharmacological effects.
The veterinary botanical practitioner prefers not just to prescribe chemically complex herbs, but often administers them in complex formulations, compared to conventional medicine preferring to prescribe a single drug. The practitioner chooses herbs or formulas for a cooperative or facilitating effect between the components to address therapeutic goals
Again, we see the commitment to the idea that plant chemicals are “natural” and that they are safer or more effective the more are mixed together in an herbal treatment, There is no compelling evidence for this belief, and it is contrary to much of the science of pharmacology that has led to so many medicine far more effective than any pre-scientific herbal treatment. There is a reason we take aspirin instead of chewing willow bark- the results is more predictable and effective. While there may be some combinations of herbal ingredients that work better or have fewer side effects when given together, this has to be proven for each by rigorous science, not simply accepted as fact based on traditional beliefs and unscientific theories.
Philosophically the veterinary botanical medicine practitioner practices conventional medicine but overlays that practice with the use of botanical medicines in a framework of botanical principles to expand their options for treatment of disease and optimizing health.
This is the standard claim of integrative medicine. It has a number of problems, which I’ve discussed in detail many times before. Basically, the addition of unproven or ineffective treatments to conventional scientific medicine doesn’t add value for the patient. Adding herbal medicine to conventional treatment will only help patients if those herbal treatments are shown to work. And any particular treatment that works should simply be part of medicine as a whole, not a separate category of “integrative medicine.”
If one is going to use alternative therapies, it is at least better not to use them as replacements for science-based medicine. However, even when practitioners of such therapies say this is what they do, there is reason to be skeptical. The same individuals often promote their treatments as safer and more effective than conventional medicine. If they believe this, wouldn’t they reach for these treatments first? Wouldn’t they likely tell their clients that their herbal treatments are better and safer, which would likely discourage these clients from pursuing conventional care? If they practice Chinese Medicine, as most of the members of the ACVBM leadership do, aren’t they going to evaluate patients and assign treatments based on the principles of this system? Since this is unscientific folk medicine, how is it compatible with a scientific approach to healthcare? The apparently simple claim that herbs aren’t meant to replace conventional treatment raises a lot of questions.
Practitioners appreciate traditional knowledge as just one potential source of information, when coupled with published research and clinical experience, herbs can be prescribed safely and effectively.
Of course, they recognize traditional folk knowledge as a reliable and important source of information, equal if not superior to scientific information about herbal remedies. This is a major danger of validating this approach as a specialty. It treats folk tradition as reliable knowledge, not merely speculations and beliefs that might or might not lead to useful insights and treatments. This attitude erodes the reliance on science that has supported all the tremendous progress in healthcare in the last 150 years and which has made us healthier that all the folk medicine of the preceding millennia.
The ACVBM also makes claims about the scientific basis of herbal medicine. I addressed some of these previously, and the updates to the application don’t add much to the previous discussion.
The ACVBM acknowledges the concerns regarding the scientific basis of veterinary botanical medicine. Where there are published scientific and clinical data supporting the overall safety and benefits of many plant medicines, the research might be dismissed as having methodological bias thus being of inferior quality to trials conducted on conventional drugs.
More accurately, the bulk of research on herbal treatments is pre-clinical, not evaluation of specific treatment approaches in specific groups of patients. The clinical research that does exist is methodologically weak and subject to bias compared with the research literature for conventional medicine. Therefore, very few of the day-to-day practices of herbal veterinarians are based on good science compared to those of conventional practitioners. This needs to be remedied before we can call herbal medicine a specialty.
However to be fair, this is also the case for clinical trials generally. for example in dogs and cats a review of clinical trials uncovered a need for more high-quality studies. And more recently a cross sectional study of veterinary randomised controlled trials of pharmaceutical interventions funded by different sources was examined and it was found that a failure to report primary outcomes, justify sample sizes and the reporting of multiple outcome measures was a common feature in all of the clinical trials. The authors suggested that findings may be affected by the source of the funding and that some RCT’s provide a weak evidence base and targeted strategies are needed to improve the quality of veterinary RTCs to ensure there is reliable evidence on which to base clinical decisions.
The evidence base for conventional veterinary medicine is far weaker and more limited than it should be. It is also far stronger than the evidence base for veterinary herbalism. And the limitations in the former don’t erase or mitigate the limitations in the latter. The focus should be on building better evidence, not on designating some of the least evidence-based practices as a board-certified specialty.
By increasing awareness, the ACVBM will help the profession as a whole practice botanical EBM. Evidence based medicine however includes not just research, but also incorporates the needs and biases of the client and patient; and the clinical experience of the practitioner; in veterinary botanical medicine this last item has been developed without official support from the veterinary profession and its regulatory bodies, yet is essential to safe and effective practice.
This is a bit of a mischaracterization of evidence-based medicine. It is a system for recognizing the strengths and weaknesses of different kinds of evidence and for making the integration of scientific research evidence into daily practice explicit and formal. Clinical experience is acknowledged as both indispensable and highly unreliable as a guide to the safety and efficacy of treatments.
The ACVBM generally privileges tradition and experience over scientific evidence by claiming that herbal therapies can be broadly described as safe and effective and worthy of specialty status in the absence of any robust body of clinical research literature. The very act of seeking specialty recognition first and then promising to do the research later shows the lack of understanding that such research is not just nice to have but a necessity if we are to have any real confidence in our treatments.
If the ACVBM wishes to advance EBM and make the profession as a whole more evidence based, they would do better to form and fund a vigorous research community doing high-quality research to validate their core beliefs (such as the superiority of whole-plant remedies and mixtures over isolated compounds) and the clinical effectiveness of their treatments. Once a strong body of evidence is available, integration of such methods and recognition as a specialty would make sense.
Bottom Line
There are some positive changes in this updated application. It is clearly an attempt to allay concerns expressed about the lack of evidence for herbal treatments, the reliance on folk wisdom and tradition to guide herbalism, and the lack of a good foundation for treating herbalism as a medical specialty rather than simply evaluating and using herbal remedies scientifically within the existing framework of science-based medicine.
However, the changes to the document do not alter the fundamental objections I raised at the beginning of this post. Ultimately, there is not yet sufficient scientific evidence to validate most of the claims made for herbal remedies. The ACVBM leadership consists predominantly of individuals who espouse unscientific approaches to health and diseases, such as Chinese Medicine, and who have demonstrated the belief that science serves not to test the truth of their beliefs but to aid in marketing them to the rest of the profession.
The best thing this group could do, for herbal medicine and for veterinary medicine as a whole, would be to stop seeking recognition and formal acceptance of their existing practices and beliefs but instead to commit to a rigorous and objective scientific evaluation of those beliefs and practices. The talent and resources spent lobbying and promoting herbalism would be far more valuable if used to test herbal treatments in objective, unbiased scientific studies. If they don’t work, then we’ll know and we can move on. If they do work, then we’ll know and we can make use of them. Either way, veterinary medicine and our patients will benefit. Recognizing unproven folk beliefs and practices as a medical specialty will not advance veterinary medicine or benefit our patients.
