Not much time to ride this weekend due to work constraints. But I did move the grullo to the front pasture to let him stretch his legs and so I could see him move. He seemed perfectly fine while walking and trotting, and immediately trotted over to investigate the mare next door and across the fence. He couldn't get into too much trouble, though, because the fence is sturdy and the top is an electric hot wire.
In the evening, after my work day was done, I went to fetch him from the pasture to bring him to his stall for the evening. On my way, the mare next door was brought in by her owners for feeding. This worked up the grullo, who proceeded to run full speed along the fence line. And this is where it got fun. He ran at full out and then stopped on his hind end mere feet before the fence in a sliding stop! He did this twice. It was an impressive sight.
After this display, he calmly walked over to me, and I haltered him with no fuss.
But this is why I bought this horse; this is what I was hoping for. He has athleticism that my other horses don't possess. If he can do that stop at will, it will be my challenge to get that same stop from him under saddle.
Oh, and I think he's over his soreness from earlier this week. If I can get done early tomorrow, there might be some work for him in the evening.