In 1799, British physician John Haygarth set out to debunk a claim that two expensive metal rods were able to draw out disease and make patients well again.

The device was called a Perkins Tractor. Haygarth secured two wooden rods made to look like the metal rods and did the same hocus pocus with them as the Perkins device over his patients with rheumatism. Eighty percent of his patients claimed they felt pain relief.

Haygarth published his findings, the first ever on the placebo effect, in a book titled, “On the Imagination as a Cause and as a Cure of Disorders of the Body.” While Haygarth discovered the effect, he did not call it the placebo effect. That didn’t happen until a paper published in 1920 coined the term in the prestigious British medical journal, the Lancet.

Years later, a paper published by a U.S. anesthesiologist, Henry K. Beecher, observed the “placebo effect,” in wounded World War II soldiers. He observed some of the severely wounded did just fine without morphine. He is credited with bringing the words into the clinical realm.

As a noun, “placebos,” became the central component of traditional double-blind clinical trials for new medications and procedures. A placebo is a harmless pill, medicine or procedure prescribed more for the psychological benefit to the patient than for any physiological effect.

Most simply, if one is evaluating a new drug, it must outperform a placebo in a clinical trial in order to be deemed effective. At least three groups with identical maladies are assigned to get the new drug, a placebo or nothing at all. Only the pharmacist making up the doses knows which of the two medications each participant gets, not the physician or nurse administering them. The results are tallied.

Yes, you might have noticed the word “procedure” in the definition above. Sham surgeries are still done in surgical and basic research with full consenting knowledge today.

Why is this in a pet column? Some people believe the placebo effect (getting better when literally nothing therapeutic is administered or done to the patient) does not happen in animals. People think this because ... well, people have that brain that allows that higher order processing to occur. So they surmise that because an animal can’t do that it can’t be “tricked,” into feeling well when it isn’t.

Research indicates otherwise. A 2003 study conducted at North Carolina State University’s College of Veterinary Medicine by veterinary neurologist Karen Munana used a small group of canine epilepsy patients. Those that received the actual anticonvulsant drug experienced 86 percent fewer seizures. Those that got the placebo … had 79 percent fewer seizures.

So what’s going on there? First guess is, some patients, human or animal, get better when nothing is done so there is a control group for which nothing is done.

There might be bias on the part of the owners. A transient “storm” of seizure activity makes owners anxious and they may seek out more treatments or more aggressive treatments, like new drug trials. The clinical situation meanwhile may pass on its own. There are several other theories to consider, too.

But another mechanism may be the laying on of hands — our hands in this case, that soothe and comfort the animal. The bottom line is that hands-on has value to both our species and theirs, despite being difficult to measure and apply with certainty.


Charlie Powell is the public information officer for the Washington State University College of Veterinary Medicine, which provides this column as a community service. For questions or concerns about animals you’d like to read about, email cpowell@vetmed.wsu.edu.

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