Good question. I wasn't sure if it was like human antibiotics, where once you start something you need to finish it so they don't build a resistance. I also didn't know if CORID had any other helpful use in treating worms.
It is the same feed they have been on for two years - Dumor Laying crumbles. We also have been mixing in DE into their feed too over the last two weeks to address the potential worm problem.
I have 26 birds (3 Guinneas, 2 ducks, 1 turkey, 2 roosters, and 20 assorted hens). Their coop at night is a 20'x20' barn room w/perches. They free range during the day. They have been losing weight (except the turkey and ducks) significantly over the last 1-2 months. Breastbone is prominent...