Injured horses tend to be rather stoic. Smokey, however has a flair for the dramatic. To be quite honest, I prefer it that way. The earlier we become aware of a problem, the sooner action to prevent further injury can be taken, and treatement can begin.
My non-veterinary opinion, based upon experience, is that he sprained a tendon or ligament in his fetlock. He had a marked limp when he walked, and was avoiding placing weight on it. There was heat and swelling in the fetlock, two of the more common symptoms of inflammation. I kept him penned up in his shelter for two days after first noting the problem. On Saturday morning I noted that The affected leg was beginning to stock up. Stocking up is a phenomenon that sometimes occurs in a horse's legs due to inactivity. It is the result of blood and lymphatic fluid pooling up in the joint, thus swelling up. To combat this I hand walked him for nearly an hour on Saturday, after running cold water over the joint. While the leg was still swollen, he was no longer limping when he walked, and was bright eyed as he followed me up and down the path.
On Sunday, our farrier stopped by, as we wanted to rule out a possible hoof abscess, a condition to which Smokey is prone. Smokey has his winter pads on, so the possibility of an abscess is not obvious to the naked eye. Not the case this time. Since he is no longer limping, and to combat the stocking up, he is no longer cooped up, and is free to roam his paddock. I checked on him this evening, and things were neither better, nor worse. These injuries generally just require time to heal.
Note to self: I've been spraying DMSO on the injury, to promote blood flow to the area. After spraying it this evening, I absent mindedly ran my bare hand down the leg. Immediately realizing my mistake, I rinsed my hand in the water bucket. Too late. My hand was tingling, and I had the taste of it in my mouth. There are just some things that I must periodically relearn.