Homeopathy. Does the placebo effect work on cows too?
I think the correct answer for that is, as well as it does on people. British Assoc. of Homeopathic Veterinary Surgeons
<reads two articles from that site>
Right. The first article I read concerned using acorn extract to treat dogs and horses who were suffering from Cushings' disease. My issues with this trial:
1) Cushings disease can be nasty and causes a great deal of suffering. Conventional treatments exist. Why were these animals not given conventional treatment?
2) All the participants were "selected" for the trial. Why? Had they not responded to standard treatment? Were they healthy enough that they might not actually need conventional treatment (and therefore would have got better on their own)? Did the person making the referrals unconsciously (or even consciously) select animals who they thought might be more responsive to homeopathy? Were the owners of these animals more in favour of homeopathic treatment and therefore have been more suggestible to viewing improvements?
3) The trial had no controls - the results were not compared to a similar group of sufferers who were (a) not treated, (b) treated with the conventional methods, and (c) treated with a placebo. This means we can't even begin to criticise the lack of double-blinding, since the experiment was so poorly designed!
4) The concept of reverting to the norm isn't discussed properly - the writer notes that most of the cases showed improvement, but that some then had spontaneous relapses which were treated successfuly, but completely fails to miss the point that the animals may have spontaneously recovered in the first place, regardless of treatment! The use of controls would have covered this.
5) Not all the animals were clinically proven to have been suffering from Cushing's in the first place - a third of the dogs only had "classic symptoms" but no blood tests had been run. "Classic symptoms" can be the same as severe eczema, so some of these dogs could have been suffering an allergic reaction which recovered completely independantly to the homeopathy.
6) There are more, but I'm bored of this paper now.
The second study concerned the treatment of dogs suffering dermatitis. This one only has the summary, but even that tells us what a poor study it is - twenty dogs were treated homeopathically. The owners of fifteen dogs saw no improvement, and the owners of five dogs said theythought that the homeopathic treatment had caused improvements. These five dogs then went through to a "double blind" trial where they were treated either with a placebo or a homeopathic remedy. One dog died, one got better before trials started, and the results of the remaining three showed that the owners were able to distinguish between the homeopathy and placebo.
Let's just say:
1) Selection methods for phase two of the trial, and
2) Sample size.
That leaves everyone to make up their own mind ;-)
Yup, I've made mine up!