It's 2024 and people think that medicated chicken feed has antibiotics in it. Guess what? It doesn't, it just has amprolium (Corid) which is most definitely not an antibiotic.
Amprolium/Corid is a thiamine analog and works to break the life cycle of coccidia by causing malnutrition via vitamin deficiency. This why if you're also supplementing your chickens with electrolytes it basically nullifies the medicated feed since the chicken is drinking more thiamine (also known as vitamin B) that feeds the coccidia. So if your feeding medicated feed to chicks don't give them vitamins in the water.
I see people sometimes feeding chickens sick with respiratory infections or other ailments medicated feed but the only benefit to feeding medicated feed in this instance is that chick starter is more nutrient dense then other feeds which can be helpful for a sick bird but it's not treating the respiratory infection.
It can also be problematic when fed to certain breeds that require more thiamine in their diet during the rearing process the most common being Leghorns and Silkies. It's not uncommon for medicated feed to contribute to wry neck in these breeds which can get immediately better when switched off medicated feed and giving these affected birds vitamin supplements.
