AFAIK, sugar pills don't work on dogs because they have no expectation that they'll do anything except taste sweet.
No argument about that, I was specifically addressing his claim that there were studies showing that this particular treatment was "proven, effective, and virtually without side effects..." This may be true, but the fact is that there are other treatments which have no possible physical impact which meet the same standard.
Seren walking and standing better is a lot harder to dismiss even if the science seems dubious. It could be his imagination again but that's less likely than with his own knee.
It could easily be Mike's imagination/wishful thinking. It might be entirely unrelated improvements, possibly even caused by some kind of increased physical manipulation of the joint to apply the light. Or it could be that the light treatment is legitimately working.
I'm not making claims either way about the effectiveness of the treatment, although I do tend to agree with Nick that if a particular wavelength is effective at promoting healing or reducing pain, simply being in sunlight or other broad-spectrum light source seems like should theoretically give the same kind of benefit. Potentially far greater benefits if there are other wavelengths that have undiscovered benefits.