Placebo effect in pets

[thaiboxerken]

Alt med advocates spout that their methodology works on pets and claim that it cannot be placebo because animals aren't smart enough to know that they are being treated or what the treatment is supposed to do. I am skeptical of such a claim. It's my opinion that pets may simply appear to be relieved of symptoms simply because they are being payed attention to more and that they are still suffering. Are there any scientific studies that validate that animals are susceptible to placebo effect?

Google is riddled with all kinds of alt med nonsense when I try to look it up.

 

[Goshawk]

I would have said that the classic placebo effect was impossible in animals. What I usually understand as the placebo effect is when you tell the patient that the medication will make him feel better--and it does. Since you can't tell a dog that the medicine will make him feel better, there can be no placebo effect in him.

So how do the alt.med people tell their dogs that the pill will help?

 

[geni]

Alt med advocates spout that their methodology works on pets and claim that it cannot be placebo because animals aren't smart enough to know that they are being treated or what the treatment is supposed to do. I am skeptical of such a claim. It's my opinion that pets may simply appear to be relieved of symptoms simply because they are being payed attention to more and that they are still suffering. Are there any scientific studies that validate that animals are susceptible to placebo effect?

Google is riddled with all kinds of alt med nonsense when I try to look it up.

Your problem here is observer bias.

 

[H3LL]

Wouldn't it be the vet' doing the examination that is experiencing an indirect placebo effect without double-blind tests?

He/she is expecting a known treated animal to improve (consciously or subconsciously).

 

[Dr. Imago]

Wouldn't it be the vet' doing the examination that is experiencing an indirect placebo effect...

Umm... yeah... it's called observer bias . (as geni already pointed out)

These are not new, mysterious conundrums of experimental science that no one has ever thought of before. Once you double-blind a study to control for such things, strangely the reported treatment effect disappears, often to the protestation, frustration and complete confusion to homeopathers, as they throw up their hands and make such silly excuses as "you can't test homeopathy by conventional means" and "treatments have to be 'individualized' or they are meaningless..."



-TT

 

[epepke]

Wouldn't it be the vet' doing the examination that is experiencing an indirect placebo effect without double-blind tests?

Well, do you notice that these treatments that are claimed to work and are claimed to be immune from the placebo effect, are

1) Related to pain, and
2) Done on animals that have been bred to be able to reflect and/or mimic the emotions of humans?

If someone showed me a good study of acupuncture on a cow, say, that make whatever it is cows get actually go away in an objectively testable way, then I'd be a lot more impressed than if Tricky Woo's owner says that she's feeling better.

 

[geni]

Umm... yeah... it's called observer bias . (as geni already pointed out)

The fractionaly longer article the brainyencylopedia article is taken from:
http://en.wikipedia.org/wiki/Observer_bias

 

[Benguin]

Surely animals are intelligent enough to respond to elevated care and attention? Certainly every one I've ever had to take to a vet (or bring a vet to) has demonstrated such a visible intense dislike of the experience as to suggest they were not completely ignorant.

If a dog or cat has got as far as connecting its owner's visible concern at its demeanour leading to a session with a vet's rectal thermometer and a week or two of being forcefeed vile-tasting pills it wouldn't be unreasonable for them to figure out they better stop moping about. Sounds to me like Pavlov answered that one.

I know it is not exactly placebo, but the idea is there!

Whilst placebo is relevant here as a possible factor to be eliminated, the main thing that homeos (and other alt meddlers) miss is that most creatures recover from most conditions most of the time. Regular medicine might speed it up a bit, reduce discomfort or reduce the risks of complications, but in general we just get better in a few hours, days or weeks.

Placebo is merely describing a phenomenon where people appear to recover quicker or show less symptoms when they are lead to believe they are getting treatment. GPs (many years ago) would routinely prescribe placebos to pill-popping hypochondriacs, partly justified by the fact they wouldn't be so stressed by their fear of imminent death if they had a pill swallowing regime. I'm not sure this happens anymore.

 

[H3LL]

Umm... yeah... it's called observer bias . (as geni already pointed out)

Sorry. Geni's post wasn't there when I opened the thread, and I didn't update before my reply.

It's a bad habit of mine. I open all the new threads that are interesting and it takes a while to get around to some.

I'll try to remember to update more often.

 

[Badly Shaved Monkey]

Just to reiterate, I think it is almost all observer bias. I think "placebo effect" as a positive aid to recovery is probably a very small factor in recovery from real physical diseases (which is what vets deal with a lot more than their medical GP colleagues).

I think "placebo effect" is cited over-frequently as a sop to both altmeddler practitioners and their patients to avoid calling either of them fools or frauds.

Ironically I used to have greater belief in the likely role of a genuine placebo effect before I started dealing and debating directly with homeopaths and their ilk. The sheer level of lies and misrepresentations and the frequency of case histories in which coincidental recovery is clearly the most likely explanation has forced me to the "fools and frauds" interpretation much more firmly than I would have accepted a couple of years ago.

Truly the woos are their own worst enemies in this regard. Ask yourselves, would you have a higher regard for the woos we debate with if they honestly answered criticism without lies and dissembling.

As a slightly interesting side topic, in double blind trials of NSAIDs on animals it is found that owers' assesments tend to have a better correlation with the objective effect than do the vets'. This is assumed to be because the owner has a wider range of clues and more exposure to the animal than the vet in a 5-10minute exam. The upshot of that is listen to the owner they are likely to be more right than you are on average, but never forget that placebo repsonse rates of up to 50% are seen in NSAID trials in animals so both vet and owner is pretty hopeless really, which is why, pace Bach/bwv11 and his ignorant cohorts you have to place reliance on trial data not your own biased clinical observation in many cases.

 

[Benguin]

What's that bit about homeopaths' shoes in your sig line mean?

 

[Badly Shaved Monkey]

What's that bit about homeopaths' shoes in your sig line mean?

It's a refernec to the fact that on their boards I have walked in their shoes quite a bit in order to see things from their viewpoint, as per the original proverb, but, as per the joke derived from the proverb, I have taken those shoes and kept them leaving them floundering.

Sorry, I'd forgotten that Aves just don't have the same amount of crinkly neocortex as we do and sometimes they don't get jokes.

 

[Benguin]

Sorry, I'd forgotten that Aves just don't have the same amount of crinkly neocortex as we do and sometimes they don't get jokes.

You've been hanging around the woos too much and developed a homeopathic sense of humour ...

 

[Badly Shaved Monkey]

You've been hanging around the woos too much and developed a homeopathic sense of humour ...

Hey, you calling my humour plain water? I thought it was highly potentised.

 

[Rolfe]

As a slightly interesting side topic, in double blind trials of NSAIDs on animals it is found that owers' assesments tend to have a better correlation with the objective effect than do the vets'. This is assumed to be because the owner has a wider range of clues and more exposure to the animal than the vet in a 5-10minute exam.

At a slight tangent to this, I refer to a paper on a woo-arthritis preparation published in the Vet Rec some months ago. It turned out that the only thing the stuff actually did was make the patients smell peculiar.

This seems to have screwed the blinding of the trial, and much more so for the vets (who had exposure to the whole range of the patients and could observe that some smelled and some didn't, and draw the obvious conclusions) than for the owners (who only had exposure to their own animal and wouldn't necessarily have connected the smell with the snake-oil). Final results - subjective assessments of the vets, just significant at p<0.05; subjective assessments of the owners, not significant, but according to the authors, nearly made it; objective measurements from force plate studies, absolutely no effect.

I find it's actually easier to impose observer bias on animals, where they can't tell you directly how they feel, and an extra observer is interposed in the system.

Quack: Look, he's much better!
Owner: Well, maybe.....
Quack: Oh yes, look at that bright eye, and he's wagging his tail.
Owner: Isn't that marvellous!
Dog: I feel terrible, you freaking idiots!

BSM also has a few wonderful stories of filmed evidence of woos hailing the wonderful results when you could see that the dog could hardly hobble, or of the "after" trial being shown in circumstances so much more favourable than the "before" trial that a difference could hardly help being seen.

The trouble is, the two groups of woos support each other. The human woos say look, it has to work because it works on animals, and the veterinary woos say you can't criticise it because it's such an accepted part of human medicine.

Rolfe.

 

[TruthSeeker]

When I was a graduate student, many eons ago, I did animal research. The reasons for the control group include observer bias, of course. But there are also effects on the animal of simply being in a study.

For instance, being handled (lifted out of cage, put in test box) causes a stress response.

Having surgery, being pilled or injected can also have effects in terms of the hpa-axis, inflammatory responses and learning. So, if you are studying pain in animals stress and hpa-axis responses are known to give rise to stress-induced analgesia (both hormonally and opioid mediated). Surgery triggers anti-inflammatory responses. Each of these can look like less pain due to the active treatment, which is not the case.

So, we always included a "sham treatment" (I don't think it is called placebo in animal work) to control for these effects.

 

[Jeff Corey]

When I was a graduate student, many eons ago, I did animal research. The reasons for the control group include observer bias, of course. But there are also effects on the animal of simply being in a study.

For instance, being handled (lifted out of cage, put in test box) causes a stress response.

Having surgery, being pilled or injected can also have effects in terms of the hpa-axis, inflammatory responses and learning. So, if you are studying pain in animals stress and hpa-axis responses are known to give rise to stress-induced analgesia (both hormonally and opioid mediated). Surgery triggers anti-inflammatory responses. Each of these can look like less pain due to the active treatment, which is not the case.

So, we always included a "sham treatment" (I don't think it is called placebo in animal work) to control for these effects.

Me, too, also decades ago. My advisor had a big NIH grant to study fear reduction in rats by means of tranquilizers. Every experiment had a placebo contol group. Depending on the route of drug delivery, the controls got an injection of saline or a p. o. intubation.
I guess we were wrong to call it a placebo, at least in terms of the original meaning. The rats were clearly not "pleased".

 

[Dr. Imago]

Surely animals are intelligent enough to respond to elevated care and attention? Certainly every one I've ever had to take to a vet (or bring a vet to) has demonstrated such a visible intense dislike of the experience as to suggest they were not completely ignorant.

Well, then that would then become a textbook example of the Hawthorne effect. Whether this is actually possible in animals is unknown, but as you lay it out it seems plausible. Rolfe, BSM any studies?

-TT

 

[CFLarsen]

I find it's actually easier to impose observer bias on animals, where they can't tell you directly how they feel, and an extra observer is interposed in the system.

Precisely. And humans can be really bad at interpreting the signals.

E.g., most people think that a purring cat is a happy cat, even long-time cat owners. But cats can purr, even when they are in severe stress or pain.

 

[epepke]

Quack: Look, he's much better!
Owner: Well, maybe.....
Quack: Oh yes, look at that bright eye, and he's wagging his tail.
Owner: Isn't that marvellous!
Dog: I feel terrible, you freaking idiots!

Which, of course, is translates as "woof woof." Unfortunately, the proof of the impossibility of the Entscheidungsproblem is translated as "woof woof."

I had an old Dalmatian (since dead) whose hips stopped working. At times, she would shiver, and that was interpreted by a vet as an indication of pain. However, she would also attempt to leap and fall on her nether regions, which I imagine must have been excruciating, but she didn't shiver then. And she always tried it, no matter how bad she got.

The thing I most admire about good vets, at least, is trying to do medicine without a patient who can tell you in plain language what is wrong or where it hurts. It's also the thing I have the most contempt for in bad vets. their inability to do so.