I just had thermography done on my horse and it was very interesting and informative. Generally, the horse needs to be at rest and out of the weather (sun and wind) for a while so their body temperature equalizes. This would be for detecting general/underlying issues. An experienced operator is very helpful for interpretation. I do think it could help with saddle fit questions if you did a baseline scan, then light exercise without the saddle, then with a rider mounted in the saddle.
I’ve tried the Bemer on myself and noticed zero difference. I have used PEMF on my horse (couldn’t afford it for me and her!) and a friend has used it on herself and her horse and we both feel differences were noticed in both horses and human. In particular, I noticed specific differences in my horse’s reactivity to the treatment between 2 different treatments that were quite informative. I don’t think the Bemer is really strong enough for a large mammal such as a horse. There is also more research supporting the effectiveness of PEMF, in my opinion. I am actually considering purchasing one because there is no local provider and I think it would be worth the investment.