I had 3 chicks die the night before last night. When I found them they all had signs of blood coming from their rectum. I took the 5 other chicks out immediately and put them in a safe place until I could figure this out. All of them are about 4-5 weeks old and all of them have a bloody discharge coming from their rectum and all are lethargic. I looked into the cause and came up with coccidia. I went and bought corid and put a teaspoon of it in their water. They are still alive this morning and showing some signs of improvement. My question is; am I giving them enough of the corid? Am I treating the correct disease. What should I do about all the other chickens and young hens that are in close proximity of their pen? Also there are ducks out with them and I know the medicine is not good for the ducks. Some good advice is needed and appreciated. Thank you in advance.