I always stay close to mine if I decide to take him out for a photo shoot, and make sure to check him for any parasites after. I also check to make sure that there isn't any predatory birds in the area, and only keep it to a few minutes. Other than that, have fun with it! A word of warning, when Paarthurnax felt grass for the first time, he was actually sort of afraid of it, and got really stressed out when it poked him. Took a few tries but after a while he got used to it and stretched out to explore. Just keep a close eye on them and you should be fine, though, and don't over stress them in the sunlight.