Left hind unsoundness

I tacked him up and started with my usual long walk warmup, which went fine. When I went to trot, he was lame on his left hind. Despite the fact that he was ears up and ready to go, I stopped and got off and untacked him. What a good sport he is to volunteer to keep going.

I checked his leg for heat and didn’t find anything. I used a hoof testers and got a slight response in the heel. I suspect he is brewing up an abscess. I turned him out, as my vet recommends movement to help keep things circulating and I have had good luck with that. I will give him a check tomorrow and see what is up and let you know. He is eating fine and seems completely emotionally unaffected.