Animals and the Placebo Effect(s)…..
If asked (or poked by a stick perhaps), most skeptics would likely be able to quickly rattle off a personal top ten list of the silliest pseudoscientific beliefs that they have encountered. There would probably be much variation between theses lists, with perhaps a few universal standards, because many skeptics specialize. My particular area of interest/specialty is irrational thinking as it applies to the practice of medicine.
As a pediatrician who specializes in hospital based care, I see more than my fair share of it. In the early days of my medical career, my already skeptical mindset was further influenced by encounters with patients suffering great harm at the hands of unproven and unscientific therapies. One child, barely able to breathe through a swollen airway by the time she was brought to our facility, was having her rapidly enlarging abscess treated by the unblocking of her stagnant chi. Ironically, she may have responded to being needled had they been a larger and inserted into the growing pocket of pus in the back of her throat. Another young patient, also having great difficulty breathing but due to an asthma flare, was failing to respond to the correction of a fictitious misalignment of her spine.
More recently I’ve dealt with the inappropriate use of hyperbaric oxygen therapy in a disabled child, and risky chelation to remove non-existant toxic heavy metals in a child with an autoimmune condition effecting their kidneys. And almost daily my life is complicated by the well-meaning but just as nutty use of antibiotics to treat what amounts to parental/practitioner anxiety, an indication for which I’m fairly certain there is no FDA approval. Science-based medicine is what I do, or at least what I strive for on a daily basis, so my list is heavily weighted towards beliefs common in both users and pushers of unproven practices.
High on my personal list is the belief that animals are immune to the placebo effect, and that the anecdotally successful use of an alternative remedy in an animal proves that it works for that very reason. This belief is frequently touted by pushers of therapies that have failed to demonstrate effectiveness in well-designed studies that incorporate a placebo control group. And it is often credulously repeated by woefully unprepared, or maybe just uninterested, journalists in the many puff alternative medicine pieces churned out each year. A wonderful example, for educational purposes, is this January 25th article in The Bulletin, an online news source for central Oregon, on the expansion of alternative therapies into the care of animals.
The piece establishes the mood with the ubiquitous anecdote/testimonial, in this case the terrific success of acupuncture in treating a dog’s chronic inflammatory bowel syndrome. The owner reveals that the therapy is working but clarifies that after more than a year of acupuncture, a restricted diet and unspecified herbs, “she’s definitely improved.” Sounds great, right. Well, not exactly. With a reasonable understanding of the placebo effect, anecdotes such as this are more easily seen for what they are: unblinded and uncontrolled studies involving one subject. In other words, absolutely meaningless.
We’ll get back to placebo in the context of treating animals in a minute, but first I’d like to touch on a few of the standard canards presented in this article as if chiseled in marble facts. The author makes several unlikely assumptions and outright false statements, the most glaring of which being that homeopathy involves the use of small doses of natural substances and that alternative medical care of pets is both holistic and individualized.
On first glance to those uninitiated in the reality bending wackiness of alternative medicine, and in particular homeopathy, this may seem like a reasonable thing to say. Homeopathy does involve small doses of various substances in the supposed remedies, although what is meant by the term natural is, as usual, unclear. Both poison ivy and snake venom are used in homeopathic remedies, and are both quite natural, but most folks would probably wince at the thought of ingesting them. But wince though one might, there is nothing to fear because homeopathic doses involve such “small” doses as to render them undetectable and unable to have any effect, beneficial or otherwise. Homeopathic remedies are inert and no decent study has shown them to be effective for any condition. Belief in homeopathy is akin to belief in magic. In fact, ask the next homeopath you bump into how they can tell the difference between a vial of tap water and a vial of deadly rattlesnake venom diluted to the point where no molecules of the substance can mathematically be expected to be found. Sit back and enjoy the show.
The claim by practitioners of alternative medicine that they are “holistic” or that they practice individualized medicine is subterfuge. Many people are impressed by such statements, and they have opened the door to our most premiere academic institutions for some pretty ridiculous stuff, but they are integral in a rather clever ploy by proponents to establish a false dichotomy between the many disparate alternative medicine entities and conventional medicine. They are always meant to imply that those evil, big pharma worshiping regular docs just treat symptoms and don’t care about the patient as an individual with a multitude of biopsychosocial factors effecting their outcome. Ironically, it is the alternative medicine woo flingers that almost universally cling to a single cause for all ailments. The single cause changes, depending on the particular form of quackery, but it still boils down to a complete and utter lack of individualization. Every patient, regardless of symptoms, has unbalanced chi to an acupuncturist. Every problem is caused by subluxations in a chiropractor’s office. To some it is all about nutritional deficiencies, while others blame unnamed toxins that must be removed from the body. Is all illness caused by liver flukes, as was proposed by Hulda Clark, or is it acidosis? Or yeast? Depends on who you ask I guess.
When I see an ill child in the hospital, I take a complete history. Rather than just throwing drugs or surgery at a symptom, I probe for information regarding prior illnesses, the medications a patient is on or has been on, their diet, family history, social history, etc, etc. I perform a physical exam. I then ask the questions that inevitably arise from my exam findings. Knowledge obtained from any one of these areas can effect the treatment options for the patient’s condition. I often am aided by social workers and medical managers that work diligently to ensure that my patients can obtain the help they need, by dietitians who focus on assisting patients in meeting nutritional goals, and by various therapists that provide valued assessment of and treatment for patients with respiratory, physical, occupational, or speech/feeding related adversities. There are psychologists and child life specialists that are available to attend to the emotional wellbeing of my patients and even their families as well. I could see ten 6-week-old male infants with bronchiolitis in a row and they might each require a different approach to their treatment based on the above factors. This way of approaching patient care goes on day in and day out in hospitals and doctors offices around the world. Naturally some are better than others, and there are some abysmal physicians that tackle patient care in ways no better than the average naturopath, throwing prescriptions of zithromax at every runny nose, but there are constant attempts by the profession to weed out bad practices such as this. The same cannot be said for practitioners of alternative medicine.
Now back to the issue of placebo and its supposed lack of effectiveness on man’s best friend. It is common to make the error of thinking that placebo is a single entity, that it is some kind of mind-over-matter effect stemming from the expectation of the patient. If that were the case, then I would agree that animals are not susceptible to placebo. But, as tends to be the case, reality is much more complicated than the fantasy world concocted by the true believer. Instead of simply being mind-over-matter, the placebo effect consists of a number of different components, some of which are pure artifact, which can lead to the appearance of a true improvement. Among these components is the tendency for symptoms to regress to the mean, which is probably the largest component of any placebo effect and the most likely reason why Maggie’s owner believes that she has responded to acupuncture. People tend to seek care for themselves or for their loved ones, pets included, when symptoms are at their peak. Other components of placebo include investment justification, novel or complicated therapy effects, or simply the desire to please an authority figure to name just a few. None of these have anything to do with an actual physiologic effect from the intervention and they only require the pet owner and veterinarian’s biased and subjective personal experience and time.
It is easy to imagine how a dog lover might interpret their pet’s behavior differently secondary to a placebo effect. It usually takes the dog a whole week to get over a flare of his inflammatory bowel disease with conventional therapy, one might say, but with acupuncture it only takes 7 days. It’s all in how you spin it and how your remember it. Human memory, while arguably better than a dog’s, is notoriously poor when it comes to recalling details over long periods of time. In addition to pet owners and the potential for their biased evaluations, it is equally easy to see how an animal might act differently because of how their owner interacts with them. Maggie might actually act more energetic and appear to be feeling better simply because his owner is paying more attention to him in anticipation of a positive therapeutic result. Perhaps other changes, such as the mentioned dietary restrictions, might have lead to positive changes in behavior that do not stem from acupuncture. The owner also mentions using herbal remedies in addition to the acupuncture. Herbs, like all drugs, have the potential to impact the physiology of the person or animal ingesting them. Many pharmaceutical agents used today were derived from the plant world. It is more likely, though still not very probable, that the dog was given an herb which led to a clinical benefit rather than acupuncture having a specific effect.
It boils down to the fact that anecdotes such as this simply cannot be trusted. We don’t know what would have happened if the acupuncture had not been tried. We also don’t know what would have happened if conventional therapy had been tried. Perhaps Maggie, instead of having merely improved, would be symptom free and far better off. Or, just maybe, acupuncture does work. That isn’t likely, since acupuncture has thus far failed to be shown effective for any condition, but my mind is always open to the possibility however slim it may be. But any reasonable person should require more evidence than this to consider any therapy beneficial. We have to employ, in addition to rational thinking, a means of being able to quickly weed out the implausible and hone in on treatments that are likely to work, and to avoid being fooled by our inherent biases. There is the reason why science-based medicine has led to such amazing advances over the past century or so and that is the scientific method.