I took a stool sample to the vets office this am to have her check for worms since the girl's laying is starting to pick up and I would rather throw out 12 eggs now instead of 25 eggs in a month or two if they need to be wormed. The sample I took came back positive for Coccidosis which is quite confusing to me. My flock has either been vaccinated or broody raised outside and the sample was from a 2 year old hen I know was vaccinated at the hatchery. Not a single bird is sick, I just did a poop board cleaning and don't see any sign of blood. I know there are different strains of Coccidosis, does the vaccine not cover all that a chicken might have? Corid is on order. Also, is Corid okay for my duck?