That has to be the craziest thing I've ever heard. Who told you that? Healthy birds do not need antibiotics, not ever.
Giving antibiotics regularly is, to put is bluntly, just NUTS. Anyone who recommended that should be horsewhipped, IMO. Take them off that IMMEDIATELY.
It is probably cocci, which is common in chicks 4-8 weeks of age. Treat with CORID, the same med in medicated feed but at a higher concentration. Once they have cocci, the feed WILL NOT TREAT it. In fact, medicated feed does not guarantee they won't get it, either.
Coccidiosis is not caused by a bacteria, but a protozoan.
Corid is preferred over Sulmet. Sulmet is harder on their intestines, can actually make the bleeding continue longer, and is not effective against all types of cocci. Corid is concentrated amprolium, same med as in the chick starter, but at a higher dosage.
Prime cocci time is 4-8 weeks of age, but by age of 12 weeks, they are usually immune to the oocysts in the soil that cause it.
Cocci is very common and highly treatable if signs are caught early and Corid administered. If you plan to have chicks around, you need to keep a bottle of Corid on hand, however, the best preventative for cocci is to give chicks a dustbath with soil in the brooder the first week of life.
Broody hen-raised chicks rarely, if ever, get cocci. They pick in mom's poop (she's immune) and get bits of soil the first week of life while out with mom.
OK will get that med. I try to keep the things I need or might need on hand. I don't know how these chicks were hatched. but I expect from eggs. Yep, I know what Cocci are. I am wondering if the man I bought them from keeps his on the Tetra because I found out he was getting a lot of chicks at an auction in Delaware and bringing them in state. He did however get these for me out of PA. I found out about the auction after the fact.He does also raise chicks from his own flock. I will no longer be getting chicks from him but now I have to find someone that will sell me some chicks or chickens to either ship day olds or live close enough to pick up. I am burning all of the old bedding and will be burning everything they have been around and chloroxing everything that I don't burn, every day until they are well or have passed. No more dead so far today. Keeping my fingers crossed.
I normally would not have done such a thing as to start them on meds as a preventative measure, but I was getting "info from an established poultry breeder". Have also always heard to start them on med feed when they are young. These chicks aren't but about 2 weeks old! I went back and checked to make sure of their age.
Didn't get this from here...no access to anywhere there have been or are any other birds or any other animals for that matter. I always take care of baby chicks first and my chickens 2nd. That way I don't carry anything from the outside to the inside.