Perhaps unsurprisingly, this is related to a terrible homeopathy study [Hill et al., The Veterinary Record 164:364-370], this time on the treatment of skin conditions in dogs. It's another example of homeopaths continuing to do small, badly designed studies, when plenty of large and properly conducted studies, and systematic reviews and meta-analyses of those studies, show that homeopathy doesn't work. The letter I am involved in is one of three letters that were published criticising the study: they can be found, with the author's reply, at The Veterinary Record 164: 634-636 [apologies for the lack of links: there's no DOI for these that I can find]. There is also an excellent discussion of the paper, and some of the responses to it, over at JREF.
The design in this study is truly extraordinary. Initially, 20 dogs with skin problems were recruited to the study. All were treated with individualised remedies by a homeopath. In 15 cases, the dog owners reported no improvement. In 5 cases, the owners reported a significant improvement. Not looking good for homeopathy so far. Still, the five improved dogs were said to have responded well to homeopathy, and went on to phase 2, which was a proper randomised and blinded placebo-controlled trial. Unfortunately, one dog had to be euthanased before the trial could happen, and another dog's skin problems had resolved completely after the first stage, leaving only three dogs in phase 2. Supposedly, those dogs did better with homeopathy than with placebo, thus justifying, as ever, "further research".
This is possibly the easiest study to criticise that I've ever seen. Put simply, the first phase lacks a control group, so improvements cannot be attributed to homeopathy. There is simply no evidence that the five dogs recruited to phase 2 actually responded to homeopathy, rather than just improved spontaneously. Then the second phase of the trial includes only three dogs. There is no way to interpret the results of such a tiny, underpowered study. Those are the main problems, but there are others. For example, all the dogs were on some kind of conventional medication, so that cannot be ruled out as contributing to any improvement.
The only reasonable conclusion from the study is that there is no strong evidence that homeopathy did anything for the dogs in the trial. But the paper concludes that the improvement seen in the five dogs (which again cannot be attributed to homeopathy on the basis of this study) is enough to justify further research. No doubt the paper will also be spammed all over the internet by the likes of Dana Ullman, as proof positive that homeopathy works. Hopefully the letter I'm a co-author on, along with the two other letters critical of the study that were published, will go some way to addressing that. The signs are not good, though. The original Hill et al. paper included the statement that "Different homeopathic remedies and different
dilutions of the same remedy have been distinguished from each other using Raman and infrared spectroscopy, even though all should contain nothing but water", with a reference to "Rao and others, 2007" [In fact, Rao et al. did not even claim that infrared spectroscopy showed any difference]. Regular readers will know that Rao and colleagues did nothing of the sort, and that to describe their paper as "discredited" would be something of an understatement. In the world of homeopathy, discredited papers never die. They are just recycled for use with audiences who don't know that they've been discredited. I suspect that this one will be no different.
As an aside, my favourite part of this study is that "constitutional signs" of each of the dogs, as used by the homeopath to pick a remedy, are listed [Table 2 of the paper]. For dog number 16, these are listed as:
Desires chicken; oranges aggravate
A clairvoyant dog! And this was published in a respected veterinary journal.