I wouldn't. If it's viral it will do no good and lead to antibiotic resistance in the future. Keep in mind that if it's a respiratory infection, antibiotics might work but the birds will likely become carriers for life. And stress may cause them to have another episode.
Have you posted about your sick chickens? In this category, at the top there is a series of sticky notes- they have links to several helpful sites and threads, as well as guidelines for helping us help you identify the problem.
I did post yesterday. Its only the one what I think to be rooster. He is just over 5 weeks and its leaking from his butt. Its smells like urine and it ends up all over his backside and belly. He was yelping when he pooped, but that has seemed to stop. He is eating, but only chick starter, he wont eat yogurt. I give him some olive oil and water mixed, and used to prepH on his vent because it was really swollen. He seems fine otherwise, but the leaking just wont stop. I noticed his vent was a little irritated Thursday, and by Staurday he was leaking bad so I brought him in and put him back under heat. I guess I am just wondering if there is more I should be doing, I feel bad.
I would not use antibiotics unless I knew what I was dealing with. I think at this time your best bet would be taking him to a vet I have no idea what could be causing this issue with a 5 week old chick.
It sounds a lot like vent gleet. May be a yeast infection, and probably systemic. Antibiotics are unlikely to help, although probiotics may. You should find a thread on treatment if you search.
Try mixing a little buttermilk in the starter feed instead of yogurt. Stay away from antibiotics especially for a 5 week old chick...too harsh and will cause more stress on its system.
Well I "think" he/she is going to be ok. It stopped leaking, but I am pretty sure it was really constipated. Once I got enough oil in em and some prepH to take down the sweeling. It pooped the biggest pile I have ever seen for such a little bird. Thanks for the help!