There is plenty of debate on medicated vs non-medicated starter feed, I'm not here to argue with anyone that uses it and feels it works for them. I choose not to use it, and it was a considered decision. I have had outbreaks of coccidiosis and know full well what is at stake. I have Corid and sulfa on hand always, just in case especially when raising chicks. My concerns with medicated are 1. introducing a thiamine deficiency in growing chicks (amprolium inhibits thiamine uptake) 2.
Possible interference in the natural immunity being built 3. A reluctance on my part to medicate when there may be no reason 4. Medicated feed is a
very low preventative dose and you can still have outbreaks and have to treat anyway.
Rather than medicate as a preventive measure I inoculate naturally by providing access to dirt from my yard in a dish in the brooder from day 1. They build immunity by being exposed to small amounts of coccidia in numbers low enough they can fight off and not get sick. I have been doing it this way for years, and my outbreak incidence is way, way down. I haven't had an outbreak in nearly 5 years now. If you do feed medicated feed, your personal choice, they still need to be exposed to the soil for the same reason, so they can build immunity, the medication just
hopefully keeps the numbers low enough that they can fight it off. Just a slightly different way of reaching the same goal. Regardless of which way you go, if you have ever dealt with an outbreak it's good sense to have treatment on hand always so that you can start right away if someone shows symptoms. Hope that makes sense, this is an article probably better said than I:
https://www.heritageacresmarket.com/medicated-feed/