A case report recently appeared in the Journal of the American Animal Hospital Association (online only edition) describing the complete resolution of nasal aspergillosis (a fungal infection) in a dog following the use of an ultradilute homeopathic remedy. So what does this mean? Is this evidence for a clinical effect from homeopathy? Is it justification for further research? Is it justification to start giving these remedies to dogs with aspergillosis along with, or instead of conventional treatment?
Epstein, S. Hardy, R. Clinical Resolution of Nasal Aspergillosis Following Therapy with a Homeopathic Remedy in a Dog. Journal American Animal hospital Association 2011;47:e110-e115.
To begin with, a case report is the least useful form of published evidence. It is essentially an anecdote, though with more detail than the usual testimonials and anecdotes used to advertise unproven therapies. It is a story told about a single individual patient, with no attempt to control for the biases that make all anecdotes of very limited usefulness in figuring out whether a medical treatment works or not. Case reports are useful for identifying new observations that might or might not ultimately lead to useful conclusions based on more formal investigation. What they cannot do is prove any particular hypothesis. So on the most basic level, this case report is not evidence that homeopathy is an effective therapy for nasal aspergillosis, or anything else.
The conclusion of the paper, and the conclusion almost always drawn from such case reports, is that further study is needed to determine if the apparent association between the treatment and the outcome (in this case, the apparent resolution of the disease) is a true association or a coincidence, and if there might be a causal relationship between treatment and response. However, there is ample reason, both within this case report and in other evidence and information available to us, to argue that no further study is in fact justified by this report.
The case against homeopathy in general has been exhaustively made many times (e.g. 1, 2, 3). In brief, the theory of like-cures-like and potentization by dilution and succussion are inconsistent with the well-established fundamental principles that underlie all of the rest of chemistry, physics, and medicine, and there is no evidence that suggests these principles might be true despite this inconsistency. Decades of research has failed to establish any consistent benefit from homeopathy greater than placebo. So for this case report to be taken as evidence that homeopathy cured this patient requires, essentially, that it be seen as a miracle that defies established science. It is not simply an extension of previously documented theory and evidence, but a narrative akin to the healing miracle stories told in support of religious claims. If it is true, it represents a fundamental change in how we understand reality.
The alternative, which seems far more plausible to me, is that this dog experienced a resolution of his disease, or at least his symptoms, that was either spontaneous or aided by the conventional therapy he had received prior to being given the homeopathic remedy. Spontaneous resolution of nasal aspergillosis in dogs has not been reported in the literature. However, other kinds of aspergillosis have been demonstrated to go away without treatment, including invasive pulmonary aspergillosis in humans, and aspergillus granulomas in humans. And in my own practice, I have seen presumed spontaneous resolution of nasal aspergillosis in a dog. The patient, a middle-aged golden retriever, had been having nosebleeds for several weeks when he was brought to see me. Rhinoscopy with biopsy and culture ultimately confirmed invasive nasal aspergillosis. The owners declined treatment due to the cost, and after a couple months the nosebleeds ceased. The dog never had any further nasal symptoms and died of an unrelated disease several years later. I know one other veterinarian with a similar story of a dog whose symptoms went away with no anti-fungal treatment.
I doubt if the authors of the current report with consider spontaneous resolution as an alternative explanation for the result seen in their case even had these two cases been published, but it is a far more plausible explanation than that homeopathy cured the patient. The only way to know for certain, of course, would be to compare homeopathic treatment with no treatment to see if those cases treated only with homeopathy recovered any more often than those not treated at all. However, this would be unethical since spontaneous resolution is likely rare, the disease is serious, and there are established effective conventional therapies available. I would argue that even comparing homeopathy with conventional treatment would be unethical since there is no sound, plausible case to be made that homeopathy has any benefit, and using it exclusively would amount to not treating the patients at all.
That leaves using homeopathy as a “complementary” or “integrative” therapy along with conventional treatment as the only ethical option. Again, there is no reason to think it would increase the chances of success for conventional therapy, but such a study could be rigorously and ethically done. If it turned out homeopathy significantly improved the outcome in a properly designed and conducted study, it would indeed be miraculous and require skeptics such as myself to re-evaluate the whole method of homeopathy. This is certainly a reason for practitioners of homeopathy to seek such a study.
For myself, I think the limited resources available for clinical research in veterinary medicine could be better spent on more plausible approaches, but I see no reason such a study should not be attempted if proponents of homeopathy are willing to fund it. But given the paradigm-changing nature of a positive result, the quality of the research would need to be extraordinary (e.g. independently replicated double-blinded, randomized, controlled trials). Such studies have never before succeeded in proving the benefits of homeopathy, so I would not expect this case to be different.
Unfortunately, if such studies are never done, or if they are done and no benefit from homeopathic treatment is found, this case report will continue to be cited as a justification for trying homeopathy on dogs with nasal aspergillosis. The appearance of an anecdote in a journal doesn’t make it any more valuable as evidence, but it makes the story far more valuable as marketing. The American Holistic Veterinary Medical Association (AHVMA) has exhorted its members to publish such case reports for exactly this reason. In fact, a previous report of homeopathic treatment for nasal aspergillosis by the same author is specifically cited as an example of the kind of report needed to promote CAVM. That case was published in the AHVMA journal because mainstream journals declined to publish it due to limitations in the quality of the information gathered and provided.
The emphasis in this effort is clearly not identifying whether or not CAVM methods work but convincing mainstream veterinarians that they do, which presumably practitioners of these methods already know from personal experience despite the absence of supportive scientific evidence. This is a classic example of scientific publication used as marketing rather than as a genuine effort to figure out whether therapies actually are effective or not. Below is an excerpt from a paper in the AHVMA journal encouraging CAVM practitioners to publish case reports (emphasis added).
The Research committee of the AHVMA has recently been reactivated with the purpose of increasing the amount of published material, which can be used by veterinarians and other interested parties to demonstrate effective clinical uses of CAVM, as well as, to assist legislative and regulatory bodies such as state boards in properly evaluating consumer complaints and legislative requirements regarding CAVM practitioners and practices. (AHVMA 2006a) This committee is working to increase the number of high-quality, useful pieces of literature, which can be used to establish the validity and applicability of CAVM, and sees this as an important action at this time. It is hoped that competent CAVM clinicians and researchers will use EBVM to document their successes. Establishing proper scientific literature and making it more readily available allows for more interested parties to learn about many of the miraculous results seen in CAVM practice. (AHVMA 2006b) Doing such actions allows for the expansion of knowledge, the expansion of CAVM acceptability and for the improvement of our profession;”
Case reporting is one way that CAVM practitioners can record their results publicly so that others can benefit from their labors. We know that investigator bias can affect research results and quantum physics has clearly demonstrated that the observer can affect the results of phenomena in the physical universe. This effect can lead to positive results that are not repeatable by others, as well as negation of procedures due to improper environment….
Critics of CAVM are quick to point out the lack of double-blind randomized studies in our field, often without recognizing the situation present in conventional veterinary practice. In many situations, this type of study is not readily applicable to CAVM processes as therapy is individualized to each specific patient’s particular situation. As an example, homeopathic cases are not easily studied in this manner, while acupuncture and herbal medicine can be.
CAVM procedures do work. We all see this daily. Because of the increasingly cooperative efforts by board certified referral practices and CAVM practitioners, it is hoped that such barriers to publication will be minimized in the future as more and more cases are occurring which have excellent conventional and alternative documentation. Case reports have been perceived to be less important in the present environment of scientific literature as they form a lower level of scientific evidence. However, case reports are an important area of scientific enquiry and one that is entirely appropriate for the CAVM community.