We got the call in about when we'll be doing therapeutic riding for the boys. Instead of a morning, we'll be trying an evening this time. On the one hand, that should be good in that I don't have to disrupt camp or other activities to take them to their riding. On the other, I do worry that they'll be worn out after the day and we'll be more likely to have tantrums and non-compliance.
They do like the riding. Nathan remembers his horse from last year: My Boy. From what I've seen, most of the children who are riding are using it for physical therapy, but there are a number of articles claiming benefits for children with autism who don't have physical disabilities. Animals are straightforward and consistent in their emotional responses, making them easier to relate to.
For my boys, I see this mostly as an exercise in compliance and communication. They are given tasks and must comply to earn their rewards. Admittedly, the horse becomes somewhat optional at that point, but they enjoy it and it gets them outside. I always enjoyed horseback riding as a child and the cost is reasonable for a summer of lessons. It's something fun they can look forward to each year.