After symptoms of lethargy and open mouth breathing, I took my 5 month old rooster to the vet. After 3 days, 2 of them on oxygen, and treatments for a possible respiratory condition or parasite, maybe gapeworm, I'm picking him up tonight. He is much improved, eating again and doing a minimal amount of open mouth breathing (which concerns me). When I took him in they said he had a 50/50 chance of surviving. I started the 5 hens on Strike III as a precation. They all show no symptoms. I have a 7 day supply of oral antibiotic to give the rooster. The vet said they still don't know if it was respiratory or parasite and only to keep an eye on the rest of the flock. Others have told me to put antibiotic in the water as a preventative. Vet says no. Also says I don't need to isolate the rooster now. I will carefully watch the flock. Should I give them all antibiotics in water? Should I listen to the vet? It's a new vet for me. I'm a new chicken owner so I'm not feeling as comfortable as I would with my other pets. I appreciate any feedback. BTW this "free" rooster has become quite expensive.