Along with many in the veterinary profession, I have been following the concerns about diet-associated heart disease in dogs since 2018. A type of severe disease known as dilated cardiomyopathy (DCM) has been reported in dogs not previously thought prone to developing this malady, and it has been associated with the feeding of certain diets. These include grain-free diets, diets with exotic protein sources, and diets produced by small-scale or “boutique” manufacturers. Collectively, these foods have been referred to in some scientific papers as “BEG” diets.
I also recently wrote an article for Veterinary Practice News on the subject critically evaluating a narrative literature review that seemed to dismiss concerns about BEG diets and DCM. Unfortunately, this review had a number of limitations, including selective reporting of relevant findings and an undisclosed conflict of interest. Some of the authors are employees of a company which produces grain-free diets and which is actively campaigning against the idea that these diets could have negative health effects. BSM, the research group behind the review, has also accepted grant funding from a manufacturer of ingredients for grain-free diets for further research into the subject, which raises concerns about the risk of funding bias.
My most recent conclusion on the subject was this:
The scientific issue, meaning the potential causal relationship between various nutritional factors and DCM, is unresolved. Further research will be needed to confirm or refute hypotheses about any causal role of pulses, exotic protein sources, and boutique pet foods in this disease. As new research is published, however, reviewers and readers should take into account the role of financial considerations of the conclusions of various stakeholders, and the relevance of these impacts to the potential for bias in the conduct and analysis of the research.
This conference included a statement from an official of the FDA Center for Veterinary Medicine (CVM), presentations by several pet food manufacturers and representatives of industry, reports from members of the BSM research group responsible for the review article I mentioned earlier, and other research presentations. Some of the abstracts and presentations are available on the conference web site while others are not. None of the presentations refer to published, peer-reviewed research.
Not surprisingly, representatives of industry and BSM were highly critical of the hypothesis that diet might be associated with DCM in dogs, and they provided arguments and limited unpublished data to contradict this hypothesis. Other researchers provided similarly unpublished data showing that dogs with DCM who were fed BEG diets recovered from the disease with diet change and supplementation of the amino acid taurine, data which supports the hypothesized causal relationship between these diets and DCM. The FDA official was studiously neutral on the scientific question, trying to explain the role of the agency in monitoring pet food safety and keeping the public informed while not unnecessarily interfering with the interests of the pet food industry.
None of the information presented at the conference establishes a definitive answer to the role of diet in DCM, and the question requires further research to answer. However, several manufacturers have since made public statements egregiously misrepresenting the state of the science and the position of the FDA. Champion Pet Foods, for example, issued this deceptive press release:
FDA Provides Clarity About Canine Heart Disease and Diet- Evidence Finds No Causal Relationship to Grain-Free Food
BOULDER, COLORADO, November 5, 2020 – The U.S. Food and Drug Administration (FDA) issued an update this week that concluded there is no scientific evidence that a grain-free diet causes canine dilated cardiomyopathy (DCM). The agency outlined the multiple potential factors that can, alone or in combination, contribute to dogs developing this rare and scientifically complex disease. The agency concluded that there is nothing inherently unsafe about a grain-free diet. This is good news for pet lovers everywhere who, for years, have seen their dogs thrive on grain-free diets for healthy and wholesome nutrition.
Historically, DCM has been primarily linked to genetic predisposition in certain breeds, but in the context of these atypical cases, emerging science appears to indicate that non-hereditary DCM is a complex medical condition that may be affected by the interplay of multiple factors such as genetics, underlying medical conditions, and diet.
FDA has not taken regulatory action against or declared any specific pet food products unsafe or definitively linked to DCM. As the scientific community looks further into the role that diet may play in these cases, we hope to explore additional avenues about ingredient levels, nutrient bioavailability, ingredient sourcing, and diet processing to determine if there are any common factors. We have asked pet food manufacturers to share diet formulation information, which could substantially benefit our understanding of the role of diet.
FDA sees this as an ongoing, collaborative, multidisciplinary scientific venture… to assess the available information and fill data gaps to determine what factors may contribute to the development of non-hereditary DCM.
Other industry organizations have issued similar statements implying that the FDA has concluded there is no causal relationship between DCM and diet, when in reality the agency has merely left the question open for further study.
Science inherently involves controversy. It functions best as a process focused on challenging and striving to prove hypotheses wrong. By its very nature, the scientific method requires criticizing the research of other scientists in order to expose bias and error in hypotheses and research methods. Unfortunately, this necessary level of controversy is unnecessarily exacerbated by the influence of ego, reputation, career goals, and money on how individual defend or attack scientific hypotheses and data. The issue of diet and DCM illustrates both the inevitable and the unnecessary conflict involved in the assessment of new ideas by the scientific community.
The core question, whether certain diets or ingredients or methods of formulation have a causal role in DCM and how, precisely, this might work remains unanswered. Those researchers hypothesizing a causal relationship and investigating this idea have always been careful to point out that the data is not yet clear nor definitive. The FDA has also been clear that they are responsible for informing the public of and investigating potential risks, but the agency has made no firm conclusion on the role of diet in DCM.
While it is understandable that critics of this hypothesis would try to undermine the arguments and evidence put forward by proponents, it is unfortunate when this is done in a disingenuous or outright misleading way. And though, undoubtedly, these critics have a genuine skepticism of the hypothesis based on the limited evidence available, the role of financial bias cannot be ignored. The publication of concerns that grain-free diets might lead to DCM, and the word-of-mouth among breed groups and pet owners with firsthand experience of this disease, have significantly affected sales of these diets. It would be naïve to imagine that manufacturers of BEG diets are unaffected in their opinions by this fact.
I have been following the research literature investigating the use of pheromones to manage behavior problems in dogs and cats since my first post of the subject in 2010. Here is a rough timeline of my conclusions over that period:
2010- Pheromone Therapy for Dogs and Cats: What’s the Evidence? “The limitations in the quality of the evidence mean we cannot definitively declare that pheromone therapy doesn’t work. What we can say is that based on the best evidence to date, it does not appear to have a benefit. Further study is certainly reasonable, but as always I question the wisdom and the ethics of widespread sale and use of products which, despite years of testing, don’t seem to have much evidence that they work.“
2010- Does the Pheromone DAP Reduce Stress in Dogs Having Surgery? “It is possible that purified or synthetic pheromones may ultimately have a role to play in treating behavioral problems in dogs and cats, or in otherwise ameliorating the stresses associated with illness and medical care. But the products currently on the market, and widely used, have so far not done a very impressive job of proving their value. Harmless? Probably. But also perfect candidate for placebo-by-proxy effects, making owners and veterinarians feel better rather than our patients.”
2016-Evidence Update: Pheromone Therapy for Stress in Cats “The results were pretty clear. While the clinic environment is generally more stressful than the home (reflected in differences in heart rate and respiratory rate), cats tolerate being handled and restrained in an unfamiliar environment better than in their own home (reflected in behavioral differences). In neither environment did the pheromone make any difference in the cats’ responses compared with placebo. The authors concluded that the pheromone had no influence on the markers of stress evaluated in this study.
Given the consistency of results across a number of studies, it is pretty clear at this point that pheromone products are unlikely to have any beneficial effects for dogs and cats.”
As usual, no single study should be taken as the definitive answer to any medical question. However, in light of the fact that pheromones have been in use and studied extensively for decades and strong, consistent evidence of significant benefits has not been seen, this study strengthens the argument that these products do not, in fact, provide such benefits.”
2018-Pheromone’s Therapeutic Use in Animals “It is clear that pheromones play an important role in the regulation of mammalian behavior, so it is plausible that they might have therapeutic value in managing problematic or pathologic behaviors. However, there is little published preclinical evidence on the composition or effects of natural pheromones or synthetic analogues, and what is available comes from proprietary or commercial sources.
Results of clinical studies of these products are mixed. Consistent, replicable evidence of clinically significant effects is not available. No evidence of any harm from pheromone products has been published, and while adverse events seem unlikely, no study has been conducted specifically to look for them.
Available pheromone products are likely safe, but it is unclear what, if any, clinical benefits they may provide for any of the variety of indications for which they are commonly recommended.”
All in all, the evidence for clinical use of pheromones in dogs and cats has not strengthened significantly in the last decade. A new study has been published which purports to support one benefit for dog and cat pheromones, but as is all too common in veterinary research, it has a critical flaw that renders its conclusions unreliable.
This study looked at the potential use of both dog and cat commercial pheromone products in reducing undesirable behaviors and promoting desirable ones in households with dogs and cats living together. The authors created a list of such behaviors and a survey instrument for owners to rate their view of the relationship between their dogs and cats. The study then recruited owners, online and through veterinary practices, who felt that there was room for improvement in the relationship between their dogs and cats to test the effects of dog and cat pheromone diffusers.
The owners spent two weeks scoring the behaviors between their dogs and cats. They were then randomly assigned a diffuser emitting either a cat pheromone or a dog pheromone, and they continued scoring these behaviors for an additional four weeks. The owners and investigators didn’t know which type of diffuser each group was using. The results showed a significant increase in desirable behaviors and a significant decrease in undesirable behaviors between the baseline and test period for both pheromones, with no difference between the dog and cat products.
Have you spotted the flaw yet? That’s right, there was no placebo control. Both groups got what they believed to be a device to improve their pets’ behaviors, and both groups saw such improvement. This is the perfect design for eliciting a caregiver placebo effect, but it is not a reliable way of testing the efficacy of a behavioral treatment.
This omission of a routine, standard aspect to any clinical trial is so glaring, it would be hard to imagine the investigators didn’t deliberately choose to omit it. Certainly, the authors were aware that this design could simply be an illustration of a placebo effect, because they address the issue in their discussion:
“There are two obvious possible interpretations of the absence of a significant difference between the treatment groups in these outcomes: either both groups were subject to a similar placebo effect; or both diffuser products were similarly effective.“
Unfortunately, their response to this problem is unconvincing. They choose to simply assert, without evidence, that the effect seen was too large to be explained by placebo effects. There was also some suggestion in the data that cats responded more to cat pheromone and dogs more to dog pheromone, which the authors also feel argues against the results being due to placebo effects. However, these post-hoc explanations are just speculation, and it is mystifying that the authors would choose not to include the most basic bias control technique for any clinical study.
Bias, of course, is always an issue in any research study, which is why controls such as placebo groups and blinding are so critical. This study had several potential sources of bias beyond the cognitive biases that could have led to an owner placebo effect. The company selling the products tested had some financial relationship to the study, providing their products for free and paying for the study to be made available as an open-access publication. One of the authors, Dr. Mills, has been a committed advocate of pheromone therapy for many years. While I don’t doubt this is based on his sincere believe in the scientific case for these products, it is well-established that research groups consistently pursuing validation of a particular hypothesis tend to have deep unconscious and conscious biases in favor of that hypothesis. Research from such sources merits careful critical appraisal, particularly when essential bias control tools are not employed.
Bottom Line This study, unfortunately, does little to clarify the potential value of dog and cat pheromones for behavior problems due to the glaring lack of a placebo group and other potential sources of uncontrolled bias. It is disappointing that despite decades of commercial sale and clinical use of pheromone products, we are still lacking robust, replicated, convincing scientific evidence of their effectiveness.
While there are likely no direct risks to using such products, I see numerous pet owners and veterinarians turn to them before pursuing appropriate behavioral or pharmacologic therapy for serious behavioral problems. The false impression that these are treatments with solid scientific support does cause indirect harm by delaying or replacing other therapies. Our pets deserve the best treatment possible, and this is always the treatment supported by the strongest evidence. So far, pheromones do not meet this standard.
I recently had a chance to chat with Jonathan Jarry and Dr. Christopher Labos on the Body of Evidence Podcast. We covered a wide range of subjects, touching on both evidence-based pet care and alternative medicine. Check it out here!
2:24 Evidence-based veterinary medicine
4:49 Extrapolating from human clinical trials
7:31 Do vets change their mind?
10:07 Acupuncture, homeopathy and chiropractic in the animal world
14:34 Pets and vaccines
17:25 A very special guest appearance
18:00 How to talk to vaccine hesitant pet owners
20:45 The cost of veterinary care
27:52 Raw food diets
32:04 The word “zoopharmacognosy”
32:52 What should dogs and cats eat
37:57 What should dogs and cats NOT eat
40:28 CBD supplements
42:51 Declawing cats
44:17 Inside cat or outside cat
46:02 Supplements to change urine pH
46:40 Feline injection-site sarcomas
49:23 Cranberry supplements
50:35 New pet parents, take it all with a grain of salt
I have spent many years fighting pseudoscience and trying to explain how science works, why it is of value, and what its role should be in decisions making, on both personal and public-policy levels. I can’t say as I’ve seen evidence that the message is getting to those who need to understand it. Pseudoscience thrives, and the rejection of science and scientific expertise is growing and spreading. From homeopathy to vaccine refusal to the anti-science clown show that is the federal government’s COVID-19 response, science seems to be losing and opinion, ignorance, denialism, and self-delusion seem to be winning. I’ll keep fighting, because what choice is there? But I fear the Age of Endarkenement is here, and the U.S. is it’s epicenter.
At least I can say I’m not alone in this. The following is an open-access editorial from the New England Journal of Medicine which expresses very succinctly how we as a nation have failed miserably at managing COVID-19, despite all of our wealth, infrastructure, and scientific expertise. The failure is one of leadership, but I would go further and suggest it is a failure of our society or culture as a whole. The anti-science loons now dominating the government are avatars of the Zeitgeist, of the society from which they have emerged. They embody the problem, but they did not create it. If after all failures of the response to COVID-19, and hundreds of thousands of deaths, 30-40% of Americans still support the administration, then the rejection of science is not a personal failing but a societal one.
Covid-19 has created a crisis throughout the world. This crisis has produced a test of leadership. With no good options to combat a novel pathogen, countries were forced to make hard choices about how to respond. Here in the United States, our leaders have failed that test. They have taken a crisis and turned it into a tragedy.
The magnitude of this failure is astonishing. According to the Johns Hopkins Center for Systems Science and Engineering,1 the United States leads the world in Covid-19 cases and in deaths due to the disease, far exceeding the numbers in much larger countries, such as China. The death rate in this country is more than double that of Canada, exceeds that of Japan, a country with a vulnerable and elderly population, by a factor of almost 50, and even dwarfs the rates in lower-middle-income countries, such as Vietnam, by a factor of almost 2000. Covid-19 is an overwhelming challenge, and many factors contribute to its severity. But the one we can control is how we behave. And in the United States we have consistently behaved poorly.
We know that we could have done better. China, faced with the first outbreak, chose strict quarantine and isolation after an initial delay. These measures were severe but effective, essentially eliminating transmission at the point where the outbreak began and reducing the death rate to a reported 3 per million, as compared with more than 500 per million in the United States. Countries that had far more exchange with China, such as Singapore and South Korea, began intensive testing early, along with aggressive contact tracing and appropriate isolation, and have had relatively small outbreaks. And New Zealand has used these same measures, together with its geographic advantages, to come close to eliminating the disease, something that has allowed that country to limit the time of closure and to largely reopen society to a prepandemic level. In general, not only have many democracies done better than the United States, but they have also outperformed us by orders of magnitude.
Why has the United States handled this pandemic so badly? We have failed at almost every step. We had ample warning, but when the disease first arrived, we were incapable of testing effectively and couldn’t provide even the most basic personal protective equipment to health care workers and the general public. And we continue to be way behind the curve in testing. While the absolute numbers of tests have increased substantially, the more useful metric is the number of tests performed per infected person, a rate that puts us far down the international list, below such places as Kazakhstan, Zimbabwe, and Ethiopia, countries that cannot boast the biomedical infrastructure or the manufacturing capacity that we have.2 Moreover, a lack of emphasis on developing capacity has meant that U.S. test results are often long delayed, rendering the results useless for disease control.
Although we tend to focus on technology, most of the interventions that have large effects are not complicated. The United States instituted quarantine and isolation measures late and inconsistently, often without any effort to enforce them, after the disease had spread substantially in many communities. Our rules on social distancing have in many places been lackadaisical at best, with loosening of restrictions long before adequate disease control had been achieved. And in much of the country, people simply don’t wear masks, largely because our leaders have stated outright that masks are political tools rather than effective infection control measures. The government has appropriately invested heavily in vaccine development, but its rhetoric has politicized the development process and led to growing public distrust.
The United States came into this crisis with enormous advantages. Along with tremendous manufacturing capacity, we have a biomedical research system that is the envy of the world. We have enormous expertise in public health, health policy, and basic biology and have consistently been able to turn that expertise into new therapies and preventive measures. And much of that national expertise resides in government institutions. Yet our leaders have largely chosen to ignore and even denigrate experts.
The response of our nation’s leaders has been consistently inadequate. The federal government has largely abandoned disease control to the states. Governors have varied in their responses, not so much by party as by competence. But whatever their competence, governors do not have the tools that Washington controls. Instead of using those tools, the federal government has undermined them. The Centers for Disease Control and Prevention, which was the world’s leading disease response organization, has been eviscerated and has suffered dramatic testing and policy failures. The National Institutes of Health have played a key role in vaccine development but have been excluded from much crucial government decision making. And the Food and Drug Administration has been shamefully politicized,3 appearing to respond to pressure from the administration rather than scientific evidence. Our current leaders have undercut trust in science and in government,4causing damage that will certainly outlast them. Instead of relying on expertise, the administration has turned to uninformed “opinion leaders” and charlatans who obscure the truth and facilitate the promulgation of outright lies.
Let’s be clear about the cost of not taking even simple measures. An outbreak that has disproportionately affected communities of color has exacerbated the tensions associated with inequality. Many of our children are missing school at critical times in their social and intellectual development. The hard work of health care professionals, who have put their lives on the line, has not been used wisely. Our current leadership takes pride in the economy, but while most of the world has opened up to some extent, the United States still suffers from disease rates that have prevented many businesses from reopening, with a resultant loss of hundreds of billions of dollars and millions of jobs. And more than 200,000 Americans have died. Some deaths from Covid-19 were unavoidable. But, although it is impossible to project the precise number of additional American lives lost because of weak and inappropriate government policies, it is at least in the tens of thousands in a pandemic that has already killed more Americans than any conflict since World War II.
Anyone else who recklessly squandered lives and money in this way would be suffering legal consequences. Our leaders have largely claimed immunity for their actions. But this election gives us the power to render judgment. Reasonable people will certainly disagree about the many political positions taken by candidates. But truth is neither liberal nor conservative. When it comes to the response to the largest public health crisis of our time, our current political leaders have demonstrated that they are dangerously incompetent. We should not abet them and enable the deaths of thousands more Americans by allowing them to keep their jobs.
Veterinary medicine is ostensibly a science-based profession. The Veterinarian’s Oath taken by veterinary graduates in North America begins, “I solemnly swear to use my scientific knowledge and skills for the benefit of society.”1 The centrality of science and scientific evidence is similarly acknowledged in statements of principles and ethics by veterinary organizations around the world.2–4
Modern veterinary practice relies on science to develop the tests and treatments we use and guide their application. Scientific research has enabled tremendous improvements in human and animal well-being, and it is indisputably the most effective means of understanding the natural world we have.
Unfortunately, the role of science as a source of knowledge, in healthcare and many other domains, is too often controversial. The scientific approach is sometimes threatening to people committed to other ways of validating their beliefs, whether organized philosophical or religious traditions or simply our individual life experiences. Also, the tools for manipulating nature that scientific knowledge allows us to develop can be misused or harmful, and negative views of some of these tools can lead people to view science and technology in general with suspicion or mistrust.
Mistrust of science and disdain for scientific expertise, especially when applied to public policy, has become depressingly widespread in our society. Too many people have become convinced that either scientists cannot be trusted or that every individual can become a self-taught expert in any subject with sufficient motivation and an internet connection. As a result, scientific expertise has lost much of its influence in the public sphere. This has grave consequences.
The resurgence of preventable infectious disease due to declining vaccination has been the most prominent example of this for years.5–11 However, the current COVID-19 pandemic has taken pride of place as the clearest and most brutal example of the consequences of anti-scientific attitudes and behavior. Tens of thousands of people have experience illness and death unnecessarily due to the refusal of their neighbors and their governments to heed the expertise of health scientists and take appropriate measures to prepare, prevent, and respond to a pandemic. Voices expressing doubt and contempt towards science have gone from the fringes to the center of society, with devastating consequences.
Prominent anti-scientific beliefs that have hampered our ability to deal with COVID-19 include claims that-12–15
The virus and pandemic are mere hoaxes
The virus was manufactured or released deliberately
The morbidity and mortality rates have been intentionally exaggerated
Facemasks are useless or even cause harm to one’s health
Unproven or disproven treatments can prevent or cure COVID-19, from hydroxychloroquine to oleander extract, homeopathy to herbal remedies
The rejection of the scientific approach to COVID has been so severe that up to 50% of people surveyed in some countries have already decided they will not accept a coronavirus vaccine when one is developed.16–18 Public health officials fighting the pandemic have been threated, and many have had to accept bodyguards or have simply left their jobs.19–21
As members of a scientific profession, veterinarians ought to be somewhat resistant to such anti-scientific views and beliefs. Any sufficiently large group, of course, is bound to have a few outliers—individuals whose commitment to some ideology or belief system another outweighs their scientific training. However, outright anti-scientific views, about COVID-19 and other health issues, should have difficulty taking root in members of a healthcare profession such as ours. Shouldn’t they?
Unfortunately, such views have long been present in veterinary medicine. A small but passionate subset of veterinarians routinely denounce scientific veterinary medicine as worthless or actively harmful and promote alternative approaches for diagnosing and treating disease. (see these articles for all too many examples- 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) These vets not only rely on untested, unproven, or demonstrably useless methods such as homeopathy, energy medicine, esoteric diets, herbal remedies, and many others, but they promote these by claiming the vaccines, medicine, foods, and other interventions developed and supported by scientific research cause disease more than prevent or treat it.22,23
It is easy to dismiss such claims as mere differences of opinion, or to write off such individuals as outliers. They are not numerous, and even most other proponents of the same alternative therapies don’t go so far in rejecting science and scientific approaches. However, these individuals are one end of a continuum of anti-scientific thinking that has led us to the crisis we face today.
This is illustrated quite clearly in the promotion of myths and misinformation about COVID-19 by some vets. (see the specific examples quoted below) Members of our profession are publicly calling the pandemic a hoax, suggesting that the rates of illness and death are exaggerated, blaming Wi-Fi or Bill Gates for COVID, and denouncing masks or any potential vaccine while promoting unproven or disproven therapies for COVID-19, including homeopathy, ozone, exotic diets, herbal remedies and others.24–32 Nearly all of these individuals have a history of disparaging science-based veterinary medicine and promoting alternative therapies. The association is not accidental but a reflection of a world view that mistrusts and misconstrues science and that privileges personal experience, historical tradition, intuition, and revelation over empirical research as methods for understanding health and disease and the effects of our interventions.
There is room for plenty of difference of opinion in veterinary medicine. The evidence is far from strong enough to define a clear standard of care for most situations. And novel or untested treatments deserve to be carefully and fairly evaluated scientifically. The use of as yet unproven therapies can be completely appropriate and consistent with a science-based perspective when the evidence is incomplete and the need is great enough. Evidence-based medicine can be a pretty big tent.
However, there is real knowledge, actual facts about the disease we treat and the methods we use, and this comes from science. Personal experience and anecdote are useful as generators of hypotheses and to help us when we have no better source of knowledge, but they are deeply unreliable and prone to bias. When there is high-quality scientific evidence available, we must be prepared to abandon beliefs and practices that contradict that evidence. Clinging to our experiences and intuitions and habits in the face of better sources of knowledge is an abdication of our responsibilities as members of a science-based profession.
Promoting pseudoscience and attacking real science is not brave or a sign of independence or critical thinking. It is counterproductive and dangerous, as the current COVID crisis illustrates. Anti-scientific views, such as antivaccine ideology and promotion of disproven or pseudoscientific therapies are not mere curiosities or legitimate differences of opinion–they are a direct attack on the scientific approach, and we are now seeing that this has consequences. As a profession based on science, we have a responsibility to resist the encroachment of such views and adhere to the scientific approach, which has more than proven its value.
In most of these columns, I try to provide practical information and evidence regarding specific tests or treatments. However, I also have the underlying goal of promoting science-based medicine and pushing back against the lowering of standards of evidence and the acceptance of unscientific views and methods. Myths and misinformation about COVID coming from veterinarians who routinely promote these views and methods is a reminder that this work is needed, and that we all have to think critically and carefully about the central role of science in veterinary medicine, now and in more normal times.1
“While the all cause mortality rate for seniors rose, the normal incidence of child mortality dropped significantly from March 2020 when the lockdown started…’The extreme lockdown response has produced a natural experiment that actually calls into question the very actions—widespread, mandated vaccines for all??that the infectious disease and public health community have been pushing for years.’” Will Falconer, DVM
“COVID-19: pretty sure I had it. It’s why I’ve been self-isolating for the past two weeks… Oh, and I’m fine, thanks to a very common homeopathic remedy.” Will Falconer, DVM
“Masks don’t work, make things worse with hypoxia, requiring them is faciscm [sic] and mind control. Executive orders mandating mask wearing and encouraging governors to do the same!!!??? Hiding behind the “respectful” or “patriotic” thing for all of us to do??!!! I recall Hitler using the “patriotic” argument , regarding his feelings about eradicating certain races of people!!! What is respectful about agreeing to a mandated act of government that many of us on the other side STRONGLY feel, based on the ACTUAL SCIENCE, that there is NO to MINIMAL benefit in wearing masks, and in fact, more and more clinical experience in the human medical and dental specialties are showing THE HARM in such practices, not to mention MANY studies over many decades?? As well as what I have said that we KNOW that Covid 19 genetic material exposure(whether you call it a virus, exosome, or toxin) in those who crash in the emergency rooms is due to HYPOXIA( or low oxygen concentrations at the level of the lung cells where oxygen is exchanged), and which wearing masks for prolonged periods actually promotes and creates those conditions??!!! Children and other sensitive people are collapsing or dropping dead while wearing mandated or recommended masks while exercising??!!! Respect?? Patriotic?? I think not!!!! Because in my opinion, the “respect” of others or “patriotic” thing to do by succumbing to the fear promoting mandate of mask wearing, is only the dress rehearsal, and will only set you all up for the same arguments used when they want to mandate the unproven and likely unsafe vaccines on the way; Horderves before the main course, when the agenda of “To Serve Man” is finally achieved, where then it may be too late. That is clear as day to me. So the heck with using “respect” and “patriotism” as reasons we should ALL be mandated to wear masks outside our homes. It is SO sad to me that 70 percent of this country supports this type of mandate!! But then again, probably that same percentage believes in yearly vaccinations for your animals, year round heartworm medication and/or flea/tick pesticides on your animals, and will be the first in line to desperately roll up their sleeves when the vaccines come marching in. Fear and brainwashing go a long way when effectively utilized!!!!” Michael Dym, DVM
“SO sad that our disconnected society refused to look back at epidemics of the past, including the Spanish Flu of 1918 , and so many other epidemics where homeopathy outshined all of the allopathic interventions of the day. While the Covid-19 mantra now remains: Wear facial coverings/Social Distancing/ Wash hands, with closing prayer: “We are all in this together”… .. Soon to come as the mantra of outpatient medicine of the near future, at your local “Urgent Care” medical center…: Test, Vaccinate if negative, and chip(trace)…. Next in line please!!… Folks, allopathic veterinary high volume or shelter clinics have already been using this same mantra for decades, relative to Feline Leukemia Virus…, Test, Vaccinate If negative, and Microchip.., Next client please!!.. Maybe they have spoken with their cronies over at MARS and Banfield on how this model has paid off wonders. I wouldn’t be surprised..” Michael Dym, DVM
“The coronavirus pandemic is ramping up as more cases are being found every day. Since there is no vaccine to protect us from the disease and no drugs to treat it, conventional medicine is of little help right now. This is a situation for which we need to turn to holistic health concepts like those found in the Edgar Cayce readings. The readings are full of body, mind, and spirit ideas to optimize a person’s health.” Doug Knueven, DVM
Generally speaking, the Cayce readings recommend a diet that consists of 80% “alkaline-forming” foods and 20% “Acid-forming” foods. To aid assimilation food is to be eaten slowly and chewed well. “Bolting” food, or swallowing it by the use of liquids, is said to be a common cause of dis-ease. Equally important as what and how food is eaten is the consumer’s mood while eating. ‘… NEVER, under strain, when very tired, very excited, very mad, should the body take foods in the system …’ The Cayce readings give us sound advice on healthy eating. The closer we can stay to the Cayce nutrition program, the stronger we can keep our bodies.” Doug Knueven, DVM
“When you see the documentary, you’ll see one of our main subtemes of therapy is intravenous Vitamin-C in high doses,” said Dr. Goldstein. “I’ve been using that since the 1970s. It’s so effective against cancer and many other diseases maladies respond to it. The Shanghai Medical Association has released an expert consensus statement on the comprehensive treatment of Covid-19 where they endorse the use of high doses of intravenous Vitamin-C for the illness. Why aren’t we hearing about this in the United States?… I’ve treated tens of thousands of animals with intravenous vitamin C already and it’s finally but too slowly catching on. If I got infected by the Coronavirus, I’d be on intravenous vitamin C in a second. We usually use vitamin C on almost all our patients, so when they do surgery or any kind of procedure, we’ve always put vitamin C in the intravenous bag… The profession of veterinary medicine is subsidized by the drug companies and the food companies, and neither of them really promote health.” Marty Goldstein, DVM
1. American Veterinary Medical Association. Veterinarian’s Oath. https://www.avma.org/resources-tools/avma-policies/veterinarians-oath. Published 2010. Accessed August 23, 2020.
2. Federation of Veterinarians of Europe. European Veterinary Code of Conduct. Brussels; 2017. www.quartiergraphique.be. Accessed August 21, 2020.
3. Australian Veterinary Association. Improving animal welfare. https://www.ava.com.au/policy-advocacy/advocacy/improving-animal-welfare/. Published 2020. Accessed August 23, 2020.
4. RCVS Knowledge, Sense About Science. EVIDENCE-BASED VETERINARY MEDICINE MATTERS. London; 2019. https://wordpress-398250-1278369.cloudwaysapps.com/wp-content/uploads/2019/11/Evidence-based-veterinary-medicine-matters.pdf. Accessed August 23, 2020.
5. Wolfe RM, Sharp LK. Anti-vaccinationists past and present. BMJ. 2002;325(7361):430-432. doi:10.1136/BMJ.325.7361.430
6. Larson HJ, de Figueiredo A, Xiahong Z, et al. The State of Vaccine Confidence 2016: Global Insights Through a 67-Country Survey. EBioMedicine. 2016;12:295-301. doi:10.1016/j.ebiom.2016.08.042
7. Hussain A, Ali S, Ahmed M, Hussain S. The Anti-vaccination Movement: A Regression in Modern Medicine. Cureus. 2018;10(7):e2919. doi:10.7759/cureus.2919
8. Lengyel K. Anti-Vaccination Movement Going to the Dogs? Am Vet. August 2017.
9. Clifton J. Stop the Shots!?: Are Vaccinations Killing Our Pets? New York, NY: Foley Square Books; 2007.
10. Kluger J. Some Anti-Vaxxers Aren’t Getting Their Pets Vaccinated. Here’s Why That’s So Dangerous. Time.com. March 2019.
11. Duan N. Inside the World of Pet Anti-Vaxxers. The Awl.com. January 2018.
12. U.S. Food and Drug Administration. Fraudulent Coronavirus Disease 2019 (COVID-19) Products. https://www.fda.gov/consumers/health-fraud-scams/fraudulent-coronavirus-disease-2019-covid-19-products. Published 2020. Accessed August 23, 2020.
13. Ian Freckelton QC. COVID-19: Fear, quackery, false representations and the law. Int J Law Psychiatry. July 2020:101611. doi:10.1016/j.ijlp.2020.101611
14. Wikipedia. List of unproven methods against COVID-19. Wikipedia. https://en.wikipedia.org/wiki/List_of_unproven_methods_against_COVID-19. Published 2020.
15. The Coronavirus Collection: Fact-Checking COVID-19. Snopes.com. https://www.snopes.com/collections/new-coronavirus-collection/. Published 2020. Accessed August 23, 2020.
16. Hern A. Nearly one in six Britons would refuse Covid-19 vaccine – survey. The Guardian. July 6, 2020.
17. Cornwall W. Just 50% of Americans plan to get a COVID-19 vaccine. Here’s how to win over the rest. Science (80- ). June 2020. doi:10.1126/science.abd6018
18. Shannon Mullen O’Keefe. One in Three Americans Would Not Get COVID-19 Vaccine. Gallup. https://news.gallup.com/poll/317018/one-three-americans-not-covid-vaccine.aspx. Published 2020. Accessed August 23, 2020.
19. Jonathan E. Fielding, Public Health Institute. When the truth becomes the threat: Standing in Support of our Public Health Officials. https://www.phi.org/press/when-the-truth-becomes-the-threat-standing-in-support-of-our-public-health-officials/. Published 2020. Accessed August 23, 2020.
20. Mello MM, Greene JA, Sharfstein JM. Attacks on Public Health Officials During COVID-19. JAMA. August 2020. doi:10.1001/jama.2020.14423
21. Susan R. Bailey, American Medical Association. AMA statement on intimidation, threats toward public health officials. AMA Web Site. https://www.ama-assn.org/press-center/ama-statements/ama-statement-intimidation-threats-toward-public-health-officials. Published 2020. Accessed August 23, 2020.
22. SkeptVet.com. CAM Vets Attacking Conventional Veterinary Medicine |. https://skeptvet.com/Blog/2013/12/cam-vets-attacking-conventional-veterinary-medicine/. Published 2013. Accessed August 23, 2020.
23. SkeptVet.com. Anti-Medicine Vets: Should Rejection of Scientific Medicine Disqualify One from Practicing as a Licensed Veterinarian? |. http://skeptvet.com/Blog/2016/07/anti-medicine-vets-should-rejection-of-scientific-medicine-disqualify-one-from-practicing-as-a-licensed-veterinarian/. Published 2016. Accessed August 23, 2020.
24. Jordan P. Patricia Jordan Facebook Page. https://www.facebook.com/patricia.jordan.1217
25. Falconer W. Will Falconer Twitter Account. https://twitter.com/homeovet
26. Dym M. Michael Dym Facebook Page. 2020. https://www.facebook.com/michael.dym.9
27. Knueven D. The Coronavirus Pandemic and the Cayce Diet. Edgar Cayce’s A.R.E. https://www.edgarcayce.org/about-us/blog/blog-posts/the-coronavirus-pandemic-and-the-cayce-diet/. Published 2020. Accessed August 23, 2020.
28. Laffly T. It Just Takes Common Sense: Dr. Marty Goldstein on The Dog Doc. 2020. https://www.rogerebert.com/interviews/it-just-takes-common-sense-dr-marty-goldstein-on-the-dog-doc. Accessed August 23, 2020.
29. CBSN New York. Dr. Marty Goldstein On Dogs & Coronavirus. https://newyork.cbslocal.com/2020/03/20/dr-marty-goldstein-dogs-coronavirus-interview/. Published 2020. Accessed August 23, 2020.
30. Falconer W. COVID-19: Remedy of the Pandemic | Vital Animal® § The Natural Path. https://vitalanimal.com/covid-19-remedy-of-the-pandemic/. Published 2020. Accessed August 23, 2020.
31. U.S> Food and Drug Administration. Court Prohibits Dallas Wellness Center from Touting ‘Ozone Therapy’ as COVID-19 Treatment. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/press-releases/court-prohibits-dallas-wellness-center-touting-ozone-therapy-covid-19-treatment. Published 2020. Accessed August 23, 2020.
32. Gellman K, Roman M. COVID-19 – Main Street Animal Services of Hopkinton. http://www.mashvet.com/covid-19.html. Published 2020. Accessed August 23, 2020.
New Ideas in Science One of the most exciting aspects of science is the discovery and development of new ideas and insights that lead to new ways of understanding and manipulating the natural world. Theories that seem preposterous at first can turn out to revolutionize medicine and other science-based fields.
Sometimes, these theories are greeted with skepticism but eventually prove themselves. The idea that living organisms too small to see exist and can cause disease took centuries to catch on and be empirically validated, but it has led to many of the most dramatic successes in medicine, such as immunization, antibiotics, and doctors washing their hands between patients. The concept that gastric ulcers could be caused by a bacterial infection was greeted with great skepticism in the 1980s, but the first proponents of the idea were awarded the Nobel Prize for their work in 2005.1
Unfortunately, it also happens that some new ideas in medicine are adopted with great enthusiasm and put into practice only to prove dangerously mistaken. The treatment of mental illness by deliberate surgical damage to the frontal lobe (aka lobotomy) also overcame initial skepticism and led to a Nobel Prize. The procedure became common and was performed on tens of thousands of patients. It is now widely recognized as one of the greatest clinical and ethical failures in modern medicine.2
More recently, the idea that many diseases, and even normal aging, were caused by oxidative damage and that antioxidant supplements could prevent disease or retard aging was proposed in the 1990s and initially supported by laboratory and observational studies. To this day, marketing for human and pet foods often includes health claims for “powerful antioxidant” supplements and “superfoods” based on this hypothesis. Sadly, the early promise of this idea has not been fulfilled in real-world studies, which have found few benefits and unexpected dangers in the use of antioxidant supplements.3–11
It is impossible to know in advance which ideas in science will lead to great benefits and which will prove mistaken and lead to equally great harm. Knowing this, a rational strategy would be to approach promising new hypotheses cautiously. A careful, stepwise evaluation from in vitro research through high-quality clinical studies and systematic reviews should be undertaken before we enthusiastically employ new ideas or methods in clinical patients.
Such a cautious approach, unfortunately, often does not suit the human temperament or the psychological and economic incentives to turn hypotheses into therapies and products. In this column, I have written about promising veterinary treatments that have been embraced well in advance of reliable evidence for their benefits, from cannabis12,13 to cold laser14, probiotics15 to electromagnetic field therapies,16 and there are many others. Whether each of these will prove the next antibiotic or the next lobotomy remains to be seen, but the regulatory, economic, and cultural features of veterinary medicine seem to consistently encourage early adoption rather than a cautious, evidence-based approach.
The Microbiome The latest example of a promising idea that is being turned into clinical tests and therapies well before this is justified by scientific evidence is the concept of the microbiome.17,18 The recognition that microorganisms can be beneficial, even necessary for a healthy organism is a legitimately revolutionary and exciting idea. While it is an exaggeration to say we each carry around more microbial than human cells,19,20 there is no doubt we harbor a complex ecosystem of bacterial, viruses, and fungi that influences our health.18
The very complexity of this system is one of the major reasons simplistic concepts of “good bacteria” and “bad bacteria” or of “balancing” the system with diet changes or supplements are unlikely to be fruitful. We have only begun to even identify the myriad organisms humans and our animal companions carry on and within us, and we have little idea what they are up to. Even crude taxonomic assessments of the microbiome reveal tremendous variation with age, geographic population, diet, and innumerable individual factors. We have a lot of work to do just understanding the composition and activity our microbiomes before we can hope to engineer them to prevent or treat disease.
Fecal Microbiome Testing Despite this, there is currently a plethora of products in human and veterinary medicine purporting to do just that. Companies such as Nom Nom Now21 and Animal Biome22 offer fecal microbiome testing for pets to “provide insight into their gut health,”22 “improve your pets’ gut and overall health,”22 and “to provide you with real insights on their unique needs [so] you can have the confidence you’re making the best choices to provide them a happy, healthy life.”21
These companies, not surprisingly, offer supplements, diets, and even fecal microbiome transplantation purportedly guided by the analysis they conduct.
In reality, there is no reliable research evidence showing that these tests provide accurate, actionable information about health or that they can be used to effectively guide dietary or healthcare choices. We lack not only clinical studies validating these specific marketing claims, but even the basic understanding of the determinants of an individual’s microbial ecology and the relationship of this to health and disease.
A few descriptive studies have provided information about the types of bacteria (other microbes are not routinely identified or studied) present in healthy dogs and cats.23 Other studies have compared the microbiota of individuals on different diets (e.g. cooked or raw, hydrolyzed)24–26 or evaluated the bacterial ecology of individuals with specific health conditions (e.g. IBD and acute or chronic diarrhea, obesity, etc.)27–30.
A Canine Dysbiosis Index (DI) has been developed which characterizes differences in fecal microbial organisms between healthy dogs and those with chronic enteropathies.31,32 Though this may eventually be clinically useful, the authors caution, “future studies will need to evaluate the clinical utility of the DI as an assessment tool for microbiota dysbiosis associated with CEs, and the usefulness of tracking microbiota over time and in response to treatment…microbiota is just one of several factors in the pathogenesis of the disease [and there is] overlap in the DI seen between healthy and diseased dogs.”31
These are all important preliminary steps towards a comprehensive and useful understanding of the microbiome, but they do not validate the claims often made for commercial fecal microbiome testing or treatment recommendations based on these tests.
The available research into the human microbiome is much more extensive than what is available for veterinary species. Here is what reviews of that evidence conclude:
The functionality of these microbial communities cannot be easily reduced to a simple summation of potential beneficial and harmful activities…While the premise behind individual microbiome testing is to inform personalized diagnosis and therapies, the current body of knowledge is not sufficient to allow for meaningful diagnoses…irrespective of what a company puts in their marketing material.33
“We are at the very beginning of understanding what one’s microbiome profile means for their susceptibility to or progression of disease…There are far more unknowns than knowns regarding the role of the microbiome and human health.”33
“Mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease.”34
Caveat Emptor While enthusiasm for new discoveries and hypotheses is a necessary part of scientific progress, the premature application of these to clinical patients can be harmful. Treatments based on fecal microbiome testing cannot be reliable when testing methods have not be validated and standardized and the clinical research showing clinical utility hasn’t yet been done. Rolling the dice on promising but unproven new ideas sometimes work out well, but the odds are greater that we will fail to help or even harm our patients if we take shortcuts in the scientific road to understanding.
1. Marshall B. A Brief History of the Discovery of Helicobacter pylori. In: Suzuki H, Warren R, Marshall B, eds. A Brief History of the Discovery of Helicobacter Pylori. Tokyo: Springer; 2016.
2. Gallen M. A brief reflection on the not-so-brief history of the lobotomy | British Columbia Medical Journal. BC Med J. 2017;59(6):302-304. https://www.bcmj.org/mds-be/brief-reflection-not-so-brief-history-lobotomy. Accessed February 17, 2020.
3. Yee C, Yang W, Hekimi S. The intrinsic apoptosis pathway mediates the pro-longevity response to mitochondrial ROS in C. elegans. Cell. 2014;157(4):897-909. doi:10.1016/j.cell.2014.02.055
4. Pizzino G, Irrera N, Cucinotta M, et al. Oxidative Stress: Harms and Benefits for Human Health. Oxid Med Cell Longev. 2017;2017:8416763. doi:10.1155/2017/8416763
5. Schürks M, Glynn RJ, Rist PM, Tzourio C, Kurth T. Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials. BMJ. 2010;341:c5702. doi:10.1136/BMJ.C5702
6. Moyer MW. The Myth of Antioxidants. Sci Am. 2013;308(2):62-67. doi:10.1038/scientificamerican0213-62
7. Pham-Huy LA, He H, Pham-Huy C. Free radicals, antioxidants in disease and health. Int J Biomed Sci. 2008;4(2):89-96. http://www.ncbi.nlm.nih.gov/pubmed/23675073. Accessed December 11, 2018.
8. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention. JAMA. 2007;297(8):842. doi:10.1001/jama.297.8.842
9. Bjelakovic G, Nikolova D, Gluud C. Antioxidant supplements and mortality. Curr Opin Clin Nutr Metab Care. 2013;17(1):1. doi:10.1097/MCO.0000000000000009
10. Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. In: Bjelakovic G, ed. Cochrane Database of Systematic Reviews. Chichester, UK: John Wiley & Sons, Ltd; 2008:CD007176. doi:10.1002/14651858.CD007176
11. Paulsen G, Cumming KT, Holden G, et al. Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial. J Physiol. 2014;592(8):1887-1901. doi:10.1113/jphysiol.2013.267419
12. McKenzie BA. Cannabis-based remebdies: No reliable clinical research evidence. Vet Pract News. August 2017:38.
13. McKenzie B. A conclusion on cannabis? Vet Pract News. July 2019:26-27.
14. McKenzie BA. Uses, Evidence, and Safety of Laser Therapy. Vet Pract News. August 2018:32-33.
15. McKenzie BA. Probiotics and today’s pets. Vet Pract News. January 2018:30-31.
16. McKenzie B. Do pulsed electromagnetic field devices offer any benefit? Vet Pract News. January 2020:30-31.
17. Allaband C, McDonald D, Vázquez-Baeza Y, et al. Microbiome 101: Studying, Analyzing, and Interpreting Gut Microbiome Data for Clinicians. Clin Gastroenterol Hepatol. 2019;17(2):218-230. doi:10.1016/j.cgh.2018.09.017
18. Knight R, Callewaert C, Marotz C, et al. The Microbiome and Human Biology. Annu Rev Genomics Hum Genet. 2017;18:65-86. doi:10.1146/annurev-genom-083115-022438
19. Sender R, Fuchs S, Milo R. Are We Really Vastly Outnumbered? Revisiting the Ratio of Bacterial to Host Cells in Humans. Cell. 2016;164(3):337-340. doi:10.1016/j.cell.2016.01.013
20. Sender R, Fuchs S, Milo R. Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLOS Biol. 2016;14(8):e1002533. doi:10.1371/journal.pbio.1002533
21. NomNomNow Microbiome – Everybody poops. https://www.nomnomnow.com/site/products/microbiome/. Published 2018. Accessed February 17, 2020.
22. Microbiome Products Restore Pet Gut Health | AnimalBiome. https://www.animalbiome.com/how-it-works. Published 2019. Accessed February 17, 2020.
23. Deng P, Swanson KS. Gut microbiota of humans, dogs and cats: current knowledge and future opportunities and challenges. Br J Nutr. 2015;113 Suppl:S6-17. doi:10.1017/S0007114514002943
24. JS S, E O, JB H, et al. Effects of a hydrolyzed protein diet and metronidazole on the fecal microbiome and metabolome in healthy dogs. J Vet Intern Med. 2016;30(4):1455.
25. Schmidt M, Unterer S, Suchodolski JS, et al. The fecal microbiome and metabolome differs between dogs fed Bones and Raw Food (BARF) diets and dogs fed commercial diets. Loor JJ, ed. PLoS One. 2018;13(8):e0201279. doi:10.1371/journal.pone.0201279
26. Sandri M, Dal Monego S, Conte G, Sgorlon S, Stefanon B. Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs. BMC Vet Res. 2016;13(1):65. doi:10.1186/s12917-017-0981-z
27. Handl S, German AJ, Holden SL, et al. Faecal microbiota in lean and obese dogs. FEMS Microbiol Ecol. 2013;84(2):332-343. doi:10.1111/1574-6941.12067
28. Minamoto Y, Otoni CC, Steelman SM, et al. Alteration of the fecal microbiota and serum metabolite profiles in dogs with idiopathic inflammatory bowel disease. Gut Microbes. 2015;6(1):33-47. doi:10.1080/19490976.2014.997612
29. Kalenyak K, Isaiah A, Heilmann RM, Suchodolski JS, Burgener IA. Comparison of the intestinal mucosal microbiota in dogs diagnosed with idiopathic inflammatory bowel disease and dogs with food-responsive diarrhea before and after treatment. FEMS Microbiol Ecol. 2018;94(2). doi:10.1093/femsec/fix173
30. Suchodolski JS, Markel ME, Garcia-Mazcorro JF, et al. The fecal microbiome in dogs with acute diarrhea and idiopathic inflammatory bowel disease. PLoS One. 2012;7(12):e51907. doi:10.1371/journal.pone.0051907
31. AlShawaqfeh MK, Wajid B, Minamoto Y, et al. A dysbiosis index to assess microbial changes in fecal samples of dogs with chronic inflammatory enteropathy. FEMS Microbiol Ecol. 2017;93(11). doi:10.1093/femsec/fix136
32. Suchodolski JS. Diagnosis and interpretation of intestinal dysbiosis in dogs and cats. Vet J. 2016;215:30-37. doi:10.1016/J.TVJL.2016.04.011
33. Staley C, Kaiser T, Khoruts A. Clinician Guide to Microbiome Testing. Dig Dis Sci. 2018;63(12):3167-3177. doi:10.1007/s10620-018-5299-6
34. McBurney MI, Davis C, Fraser CM, et al. Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions. J Nutr. 2019;149(11):1882-1895. doi:10.1093/jn/nxz154
I have been trying to keep up with the clinical trial literature evaluating cannabis (primarily CBD) in veterinary patients. There is a lot of research happening right now, so it is challenging to keep current even on this limited subset of studies, but fortunately I know some folks who are much more involved with CBD research and can pass along new evidence as it gets published. So far, clinical trials show promising results for treatment of arthritis pain in dogs and not so promising results in one study evaluating CBD for treatment of canine epilepsy. Another small study looking at treatment of arthritis in dogs (along with some lab animal and human effects) has recently been published which strengthens the case for use of CBD in these patients.
This study included a relatively small number of dogs (20) divided into 4 groups: placebo, two different doses of plain CBD, and a type of CBD packaged chemically into little globules called liposomes, which can influence how some drugs are absorbed and distributed in the body. The study used subjective assessment of arthritis symptoms by both veterinarians and owners, and both groups were blinded to the treatment each dog received.
The study found statistically significant, and potentially clinically meaningful improvements in most measures for the high-dose and liposomal CBD and no improvement for the low-dose CBD or placebo. The lack of a placebo effect is always a bit of a concern since such an effect is usually seen in pain studies in dogs, and the absence of a caregiver placebo can be a sign of a methodological problem in a study. However, the apparent dose-response, with greater improvement seen at higher dose, is a good sign since this is commonly seen with most pharmaceutical effects. There were no signs of adverse effects or abnormal changes in blood tests.
The non-clinical measures in mice also showed some changes in modulators of inflammation which support a plausible mechanism for clinical effects, a necessary step in building an overall picture of the value of any drug therapy.
While this is a small study, and no single trial is sufficient to make a definitive judgment, this is good quality evidence which is consistent with other existing studies, and it strengthens the case for CBD as a potential treatment in dogs with arthritis. All of the usual caveats apply- this doesn’t support any of the hundreds of other claims for CBD; many over-the-counter CBD products have uncertain ingredients and poor quality control, so even if CBD has real benefits they may not be seen with poorly regulated products; there is stronger evidence for the benefits and potential risks of NSAIDs, and these are still a first-line treatment for arthritis in appropriate cases, along with weight management and other existing strategies. On the whole, though, the evidence is getting better and better, and the value of CBD for dogs with arthritis seems likely to be quite high.