Homeopathy is a popular but a very controversial treatment. The scientific studies demonstrate that homeopathy is pretty much useless for humans: all of its benefits are no more than “placebo effect” (1).
What is placebo?
Placebo is a substance that is not medicine (sugar pills, plain water etc.) but that a patient who is taking it believes is medicine. Because of it, patient experiences the improvement in their health. This improvement results from expectations and patient’s psychology and is unrelated to placebo itself.
Placebo cannot cure any diseases, because it has no therapeutic effects or benefits, but believing it does, can relieve the symptoms temporary.
The benefits observed in alternative medicine are due to “placebo effect”. Homeopathy is essentially a type of placebo.
Homeopaths do not limit themselves with human patients; they also believe homeopathy has a lot of to offer for animals too.
A branch of homeopathy that treats animals, called veterinary homeopathy.
It is not hard to understand why: Homeopathy promises no side effects, in contrast to real medications. For people who are conditioned to fear chemicals, homeopathy stands out as more “natural”, less risky type of medicine.
The research of veterinary homeopathy is limited, but some of studies claim that homeopathy is effective for a wide variety of conditions in pets and livestock (3, 4).
If benefits of homeopathy for humans are due to placebo, are animals also capable to experience “placebo effect”?
Apparently, placebo hypothesis is not sufficient to explain the benefits of homeopathy for animals (5). Animals are unaware that medication is given to them, and if they do, they do not respond similarly to humans. Animals have no expectations that given medication will make any difference for them.
Animals are not susceptible to “placebo effect”. For this reason, animal studies are more useful than human studies in answering the question of whether homeopathic remedies have specific effects compared with a placebo (5).
Homeopathy is a two century old belief system. It is based on principle that “like cures like” or “similitude”. For example, hay fever is treated with diluted onion preparation that supposedly causes similar symptoms to hay fever like sneezing, or watery eyes. Homeopaths also believe that diluting the original substance many times does not make it ineffective. In contrary it gets stronger. Homeopathic treatments are so diluted, that not a single molecule of the original substance is left (2).
The mechanism by which homeopathic dilution works is explained by “water memory”, that water somehow retains a memory of substances it previously contained.
“Like cures like”, high dilution and “water memory” are not supported by science. From scientific and logical point of view, these principles are nonsense, so there is no reason why homeopathy would work. This is why homeopathy is called as pseudoscience - fake science, a discipline not based on science.
Of course, nothing prevents homeopaths to gain some credibility by trying to appear “scientific”. Homeopaths own scientific journals (example: Homeopathy, published by Elsevier) whose main purpose is to defend homeopathy. Furthermore most of research on homeopathy is done by homeopaths and is published mainly in alternative medicine journals. This is where most of so called positive evidence for homeopathy comes from.
Homeopaths and their supporters do not want to do the real science and test their ideas properly. They only favor positive evidence even when it’s weak. They, of course, forget and avoid the evidence that conflicts with their views (6).
When well-designed studies demonstrate homeopathy does not work, the homeopathic belief system remains unshaken. Homeopathic beliefs are never challenged. Faced with negative evidence and criticism from skeptics, homeopaths demand more research and funds, hoping to produce another positive study that finally “will prove homeopathy truly works”.
Homeopathy receives some generous funding. For example, National Health Service (NHS) in United Kingdom spent £4 million on homeopathy annually (7). These funds could be given for better treatments. Fortunately, NHS started to listen to scientists and even considers banning homeopathy altogether (8). NHS does not recommend homeopathy for any health conditions, because there is no scientific evidence proving that homeopathy has any effect (9).
Veterinary Homeopathy: no evidence
Science is an important tool to separate nonsense from the truth. Of course, it does not mean that every study is good. The great number of scientific studies are false, biased and flawed (10).
Smaller and lower quality, biased studies are in favor of veterinary homeopathy (1, 19). However, systematic review (11) found that homeopathic studies were badly designed, sometimes missing important information and vague. Moreover they had obvious biases and vested interests. In short, these studies contained nothing reliable and failed to provide convincing evidence that homeopathy has any effect for animals (11).
Meta-analysis conducted by two homeopath researchers admitted that studies on animals were indeed very poor quality, rendering them useless (12).
When evidence was taken from larger, higher quality studies, homeopathy showed absolutely no benefit (1, 11). It was no different from placebo.
Homeopaths may sometimes be lucky and obtain false-positive evidence just by chance (6), especially if they try this many times. It does not mean that such evidence offers any hope for homeopathy. There are many other factors that could be confused with positive effects attributed to homeopathy (18).
Some diseases improve with time without any treatment (natural healing), some animals could be misdiagnosed and humans who treat these animals may
If homeopathy is a lie, why so many people swear that it helped for their pets?
It’s again a placebo effect - not in animals, but in their owners and veterinarians.
It even has a name - “caregiver placebo” (13). What is “caregiver placebo”? A caretaker and veterinarian perceive the treatment being more effective than it really is. In one randomized, double-blinded study, dogs with osteoarthritis were given real medication and other dogs got a fake medication (placebo). Dog owners and veterinarians were asked to evaluate the treatment in 6 month period. About half of owners and veterinarians believed that treatment was successful. However tests showed that the dog’s health was the same as before the treatment (13).
Why Homeopathy is harmful and unethical
Humans are really bad at guessing how animals feel. For example, it’s very difficult to understand when a cat has a pain (14). Take this for example: a cat has recently had a surgery. The wound becomes infected and causes a great amount of pain. Caretaker decides to treat such a cat with homeopathy, instead of antibiotics and painkillers. As homeopathic treatment progresses, cat owner becomes optimistic and feels that her cat is getting a better. However, a cat suffers.
“Homeopathy makes people feel better about their pets’ health without actually making the pets feel better”, says Brennen McKenzie (15), a veterinarian and skeptic.
But homeopathy has no side effects, what is the harm then?
Animals have no choices when comes to their health treatments. Choosing homeopathy is the same as “doing nothing”, because homeopathy is not a medicine. Homeopathy equals to no treatment and carry with it related risks (16).
Homeopathy may delay recovery and deprive the animal of adequate therapy. In some serious conditions, homeopathy could be even deadly, because animal was denied the effective treatment that could save its life (17).
Using homeopathy and other unproven treatments on animals is irresponsible. Useless treatments may cause unnecessary suffering to animals. Even if humans allow themselves be fooled by placebo, it is unethical to force the same unproven therapies on animals. Animals deserve the real medicine - science based medicine.
The veterinary homeopathy research is flawed and should not be trusted.
The studies show, the homeopathy is no better than placebo. It follows, that homeopathy does not work both for humans and animals.
For sake of animal welfare, animals should not be given ineffective treatments. Veterinarians should actively reject homeopathy and promote only evidence based veterinary medicine.
(1) Shang, A., Huwiler-Müntener, K., Nartey, L., Jüni, P., Dörig, S., Sterne, J. A., ... & Egger, M. (2005). Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy.The Lancet, 366(9487), 726-732.
(2) Işıl Arican, Homeopati nedir? : Tavşanın suyunun suyu, 12/06/2012
(3) Bonamin, L. V., & Endler, P. C. (2010). Animal models for studying homeopathy and high dilutions: conceptual critical review. Homeopathy, 99(1), 37-50.
(4) Mathie, R. T., Hansen, L., Elliott, M. F., & Hoare, J. (2007). Outcomes from homeopathic prescribing in veterinary practice: a prospective, research-targeted, pilot study. Homeopathy, 96(1), 27-34.
(5) Hektoen, L. (2005). Review of the current involvement of homeopathy in veterinary practice and research. The Veterinary Record, 157(8), 224-229.
(6) Smith, K. (2012). Homeopathy is unscientific and unethical. Bioethics, 26(9), 508-512
(7) Fisher P., Ernst E.. Should doctors recommend homeopathy? BMJ 2015; 351:h3735
(8) Homeopathy 'could be blacklisted' by James Gallagher (BBC), 13 November, 2015
(9) NHS Choices - Homeopathy, http://www.nhs.uk/Conditions/homeopathy/Pages/Introduction.aspx
(10) Ioannidis, J. P. (2005). Why most published research findings are false. Chance, 18(4), 40-47.
(11) Mathie, R. T., & Clausen, J. (2015). Veterinary homeopathy: Systematic review of medical conditions studied by randomised trials controlled by other than placebo. BMC veterinary research, 11(1), 236.
(12) Mathie, R. T., & Clausen, J. (2015). Veterinary homeopathy: meta-analysis of randomised placebo-controlled trials. Homeopathy, 104(1), 3-8.
(13) Conzemius, M. G., & Evans, R. B. (2012). Caregiver placebo effect for dogs with lameness from osteoarthritis. Journal of the American Veterinary Medical Association, 241(10), 1314-1319.
(14) Robertson, S. A., & Lascelles, B. D. X. (2010). Long-Term pain in cats How much do we know about this important welfare issue?. Journal of feline medicine and surgery, 12(3), 188-199.
(15) Brennen McKenzie, Alternative medicine and placebo effects - for pets? 10/9/2014, randi.org
(16) Shaw, D. M. (2010). Homeopathy is where the harm is: five unethical effects of funding unscientific ‘remedies’. Journal of medical ethics, 36(3), 130-131.(17) De Verdier, K., Ohagen, P., & Alenius, S. (2003). No effect of a homeopathic preparation on neonatal calf diarrhoea in a randomised double-blind, placebo-controlled clinical trial. Acta Vet Scand, 44(1-2), 97-101.
(18) Rijnberk, A., & Ramey, D. W. (2007). The end of veterinary homeopathy. Australian veterinary journal, 85(12), 513-516.
(19) Ernst, E. (2013). Homeopathy: A Critique of current clinical Research. Skeptical Inquirer, 36(6).