I would try to think of other "exhilarating" things he can do that don't involve pressure on his ankle. Depending on what your funds are like, riding a motorcycle, a hot air balloon ride, etc. For my husband's birthday, I got him a day of flying a helicopter from Xperience Days http://www.xperiencedays.com

There are tons of "experience" gifts you can get him. Driving a race car, flying a plane. Check out the site. I think I spent about $100 on the helicopter thing. He was completely blown away and couldn't believe I actually thought of something like that or that something like that even existed. They send you a cool black gift box to present the gift in.

But there must be a lot of less expensive things he can do more than just once. ATV, motorcycle, 4x4 with a jeep or whatever ... depending on if you have any of these things or know anyone who does. And assuming these are things he can do with his injury.

Also, go to events as a spectator. Mountain bike events, motorcross events. Find things to go to that he might get a thrill just watching. Maybe something he's never done before, but might like. A monster truck rally or whatever might float his boat.

I like the ideas of ways he can play with the dog.

A camping trip?

You have tons of great suggestions. (Oh, and the first I thought of, of course ... was the first thing someone else said. ... Seriously, that's the best gift EVER for a guy!!! And that's free!)