I have gotten my dog cold laser therapy for her allergies and auto immune disease. I've also seen it done on dogs for hip dysplasia and arthritis, epilepsy, other allergy dogs, and on dogs post surgery to speed up healing.
On every other dog that I either witnessed personally or read the testimonies of (which were about 20 in all) it worked moderate to very well. In my dog, it did not work. She had 4 weeks of treatment.
I felt the laser myself and it feels like nothing at all. The vet, tech, or you if you feel comfortable, will hold the laser on the area of the dog that needs healing and on the thyroid gland in allergy, autoimmune disease, and epilepsy cases.
The laser will sound when it's finished, and it's a pretty fast process. You start off with 3x a week, then 2x a week, then once a week.
In some lit I've read on the internet, although my vet disagreed with it, it can "backfire" because the cells are stimulated too much. I believe this was the case with my dog but it's hard to say. She did get worse in 4 weeks, but that might have happened anyway.
BTW my dog's case was very hard to treat. She had severe auto immune diseases that responded to nothing except glandular therapy. My dog's cost was if I spent $200 then I would have unlimited treatments, I think it was $30 for one treatment I want to say.