He refused grain with that same soulful look that Loki gave me years ago after eating mountain laurel. He then walked in a circle and settled back down, with a slight grinding of his teeth. I was really starting to suspect tummy issues at this point. But just to see how bad it was, I brought out a couple of flakes of hay to see if that was more interesting. Yes, it was. Rex got up and joined the team for a chow-down on the hay, so I left him to it. His instinct was probably telling him to eat roughage to try to settle whatever was wrong. (A goat that won't eat at all is a goat that is sick.)
This morning, I checked Rex again. He was back to his spot in the barn, head up, cool nose, willing to get up when I asked but no more than that. His eyes were still a bit pale, but not deathly white. But this morning he also had a little evidence of diarrhea. Ah-ha. It is tummy trouble, and he's working on processing it... He nibbled on some hay while everyone else was chowing down on grain, but wasn't really interested. He was back in the barn before I was done refilling the water.
Just to help with my peace of mind and hopefully his tummy, we had a quality "conversation" over some activated charcoal. (He didn't like it just like Jared eats hot peppers - rubbing his nose all over the barn wall to get rid of it.) I left him some more hay to settle his rumen, and plan to keep giving him hay and not pushing grain on him.
I'll check on him again tonight, to see if his ankles are swelling or if his tummy is starting to slosh. Hopefully we've caught this before his rumen gets totally out of whack.