I read an article on alternative medicine for animals, and since many alternative treatments have not been conclusively proven to have benefits beyond the placebo effect, I wondered: Does the placebo effect apply to animals?
After all, anyone who has ever tried to give a pet medication would agree that they have no idea that you are trying to help them.
Hardly an expert opinion here, but I would be willing to bet lots of money that the answer is “no”. Placebos work on psychology; you think you’re being given something that’s going to help you. The power of suggestion. As you point out, animals don’t know what you’re giving them is supposed to help them. So how can they react to the power of suggestion?
I definitely second the non-expert opinion! The Placebo Effect only works when the patient is aware that some benefit is supposed to be derived from the treatment. An animal has no such awareness of this effect, hence the use of a placebo would affect the animal in no way.
Just reiterating here…
Regards…
There is axually a more interesting side to this question.
Obviously, animals don’t have the same conceptions about pills and elixirs that humans do, but it would be interesting to conduct controlled experiments to see if the placebo effect might operate in situations that animals DO seem to understand as “beneficial.”
For instance, many animals lick their wounds. What if a prosthetic “fake wound” made of that animal’s hair and blood were applied OVER a real wound, so that the animal only BELEIVES they are licking their wound, when in fact they are licking the prosthetic. Would there be an improvement in healing over other non-licked wounds anyway?
There may be other testable situations where animals “believe” they are doing something beneficial, which could be replaced by neutral behaviors unbeknownst to the animal.
Interesting…
Well, you’re right, this might make an interesting experiment. But I’m going to stand by my original non-expert opinion and bet lots of money that it doesn’t make a difference. Placebos are used on people when the doctor believes there isn’t really any illness (if they thought the person really was sick, they’d give them the proper medication, of course). I wouldn’t think it would be possible for an illness to be “in an animal’s head”.
As for your example… I assume the reason an animal instinctually licks its wounds is to clean it out. If the wound is covered, even if the animal * thinks* it’s cleaning out the wound, it’s not getting the benifits of actually doing it. Like I said, experimentation could prove me wrong, but I’m standing by my opinion.
I also think that saliva actually has a beneficial effect on wounds other than just the cleansing properties. As in human saliva, there are enzymes and beneficial bacteria which aid in the healing process. Taking away this benefit would, in my non-expert opinion, hinder the animals healing process. However, animals are very intuitive. It’s possible that the Placebo Effect could be “taught” to an animal, but I don’t think it is a naturally occurring event.
Regards…
In people this is called The Hawthorn Effect.
As I recall, it says that simply measuring people makes them more efficient workers.
This occurred when they tried to find the optimum light levels at a GE facility. When they raised the levels, the efficiency improved. When they lowered it, it also improved.
People just liked being studied.
The same effect could apply to animals. They would like the attention of getting a pill, and feel perkier.
There’s another sense of the placebo effect however, namely, that people with REAL illnesses also show some improvement (over that shown by no-treatment controls) if they believe they are receiving treatment, whether or not they axually are.
This would be the sense I would be testing; not whether or not an animal’s imagined illness could be cured by a placebo, but whether or not an animal’s real injury would show improvement if they BELIEVED they were licking their wounds (even though they weren’t), as opposed to controls who were not allowed to lick their wounds at all.
There was a book written about this titled,IIRC, “Management and the Worker.” In effect, this was the first of the “management guru” books and it created quite a stir. Up until the landmark study of light levels versus productivity was done, managers typically regarded workers as necessary evils and treated them as sub-human. The study did not reveal that people like to be studied, it revealed that people like to be treated as if they are of some value. The fact that “management” suddenly exhibited an interest in “labor” was sufficient to bring about an increase in productivity. Intensifying the interest resulted in even more gains in productivity. This seems self-evident today but when the book was published, it had the light of a revelation. It is still worth reading.
The answer is … yes. Okay, technically the placebo works on the pet owner. Interpretation of the animal’s wellbeing is largely based on what the owner thinks. How the owner responds to the pet affects the animal’s self-perception. So if the owner (or others who are in relationship to the animal) change their reactions based on their own estimation of the effect of the placebo, this can affect the animal’s wellbeing, which can affect disease process. The owner’s reaction causing the animal’s reaction is the placebo treatment (just as the individual’s expectation is the placebo treatment in human placebo reactions).
Probably has less effect than on humans, where the effect is first-person. However, my sister the vet has seen utterly miraculous results from owner prayer (or even vet prayer) when all other treatments have failed. Barring divine intervention (which I won’t say isn’t happening or helping, but that’s a different discussion), the owner’s deep belief in the effectiveness of the prayer changes something about how they relate to the animal, and the animal improves - not just in the eye of the owner (‘he’s still limping terribly, and whimpers when he moves, but he is clearly much happier’), but also in clinical details (‘dog no longer has seizures’ or ‘dog regains function of limb despite existing nerve damage’).
As far as I know, giving a placebo to the animal to change the owner’s behavior isn’t a standard of practice. However, I’d be surprised if it wasn’t done periodically anyway - treating (or at least managing) the owner is kind of part of the job.
I would call it the “Clever Hans” effect. There was a horse (in the 1800’s?) that could do arithmetic. If you asked a question he would stomp his hooves a number of times to signal the answer. Upon investigation it was found that the horse could not do arithmetic if it could not see his owner and he could not answer any problem that his owner did not know.
The horse was reacting to subtle (unintentional, by all accounts) body language of his owner. As the horse started to clop out the answer the owner would tense up in anticipation. As soon as the horse got the correct answer the owner would relax and the horse took this as a signal to stop clopping.
My point is that if you give an animal something that you believe will help it, it will clue in to your relief and believe that something is being done.
However, in most cases it is probably simple cases of confirmation bias. After all, most dowsers believe that they can find water.
Hey, that’s really cool! I hadn’t thought of that. I’d considered posting the same question as the OP but talked myself out of it. Just goes to show that there are no stupid questions!
So when they’re testing drugs for animals, do they do double-blind studies?
re: double-blind studies in animals
I have no idea. I doubt it, because the handlers are either general staff (who won’t know the details of what the treatment is supposed to do) or trained clinicians, who probably don’t expect a massive improvement in any particular case, but are looking for what the optimal dose/schedule/efficacy is. They aren’t looking for ‘any’ improvement, they are looking for ‘what kind’ of improvement. So I’d think that there would be less transfer of observer perspective to the animal.
The other thing that I recall is about side-effects (antiplacebo effect?). Dogs who have chemo don’t have as horrible side effects as humans, because they don’t know that the chemo is toxic. To test that it isn’t the animal system that is different, some cancer centers have tested what happens if you don’t tell people that the chemo is highly toxic… and sure enough, the more the people think of the chemo as helpful and non-toxic, the lower their level of side-effects. Dogs whose owners think of chemo as deadly-toxic have more negative side-effects, though again, part of that is the owner’s interpretation, separate from the actual symptoms.
…is the placebo effect different in animals.
Dummy treatments can have an effect on animals, and yes, they do perform double-blind studies on veterinary medicines and procedures.
Many lab animals react positively to being handled. This can actually affect survival rates. Tests done on rats, dogs, cats, and monkeys can be affected by how interaction the subjects have with humans.
Think about it. If you were a dog, and you were in the control group, and you got fed and watered regularly but stayed in your cage 24/7, wouldn’t you tend to do worse than a dog that got some treatment that involved getting you out of that stupid cage?
There was a famous psychology experiment in which the lab technicians were told that one group of rats was smarter than another, even though the two groups were exactly the same. Lo and behold, the “smart” group turned out to run the mazes better, merely because of the increased attention from their handlers. (Apologies for the lack of a cite; if anyone is interested I can find it.)
I believe “double-blind” experiments are standard even for animals exactly because of this kind of effect.
KeithB has the “Clever Hans” story pretty much correct, but IIRC it was in the early 1900s, not 1800s. But Hans apparently could do the trick even if the owner was absent, as long as he could see the questioner, and the questioner himself knew the answer. If these conditions weren’t met, Hans couldn’t do the trick. It was theorized that he was picking up very subtle body language on the part of the questioner, but I don’t believe the exact clues Hans was using were definitely established (but it probably was tensing up just as Hans reached the right number).
Thanks, guys, I learned something!
(clinical training does not preclude human nature, I guess…)