I'm not totally new to chickens, I've had them nearly 2 years; however, this is my first time raising broilers. I got Cornish Crosses and they're 5 1/2 weeks old. I am raising them non-GMO/organic (but I did have to treat with amprollium once, for 5 days) as best as I can. Lately, I've noticed some of the chicks sneezing, so I've been giving them UP/ACV all week in their water, but they haven't been improving. Today, I noticed two seeming to struggle breathing, and one of them makes a pitiful squeaking noise every time it breathes and it's rather listless. My questions: 1. I've been told (& read the bottle) that Sulmet is okay to use for broilers as long as I wait at least 10 days after treating to butcher (which won't be a problem). I've also been told that Tylan may work better. Any opinions? Is Tylan okay to use on meat birds? 2. Do I treat just the ones I notice sneezing or should I just give the whole batch (25 chickens) the treatment? 3. How long do you think they'll last before treatment? Since it can't get any of the meds tonight or tomorrow. Thanks so much in advance!