Silas had hookworms!
He was at the vet yesterday to get fixed and they discovered them. If he had gone without medication for another week he would be dead! It's all fixed now, thank goodness, and he should be gaining lots of weight in the next few days and weeks. The boy is down with him now, and he comes home this coming Sunday.
I went to Target today and bought him a bunch of stuff, but not nearly as much as I wanted to! I can tell that this is going to get very expensive, very fast.