My chicks are 2 weeks old, and they were pooping blood this morning. there was lots of it so not just one chick. However thid afternoon I come down with some SulMet in hand, and they have eaten food as per usual, there looks to be NO fresh bloody stools, and they're lively. What do i do? I believe they have gotten a shot of vitamins already, before I got them 2 days ago.