I have 22 birds that are 9 weeks old and I first noticed 2 weeks ago that there were a few (who I have no idea) that had blood in their poop. I had them vaccinated (Merck's) but did not put them on a medicated feed as little chicks. So 2 weeks ago I put them onto a medicated feed thinking it would maybe fix this issue. I am still seeing a couple of poops a day that have blood in them - is this normal? What is it indicative of? When they were 3 weeks old I fed them some earthworms but only did twice before I found out that they can carry gape worm (which from what I had read can affect their respiratory system). Suggestions much appreciated.