The first had it only in one eye it seems almost cleared up. Then my EE showed in one and now both. Better safe than the other..I would give for 7-10 days. You have had 2 birds come down with it several days apart so it may be traveling accross your birds with a 3-4 day incubation period. 7-10 days should be enough to kill the bug and break the cycle.
I shop around. Even from the company I listed, there are other brands of the same generic drugs that are more expensive. Thats why I posted pictures of the ones I order.
Tylan is often recommended for resp diseases in chickens. I personally dont stock it as I use others that are cheaper and I feel as effective - but thats anecdotal and had no statistical merit.
My chickens are 7500 miles away so I have to treat them remotely. I find that the above cures most things.
It is important to make up fresh solution each day. Try not to make up too much at a time as wasted antbiotic filled water is bad for nature as it increases the speed at which resistance to the antibiotic develops.
Some drugs are listed as restricted in Ca. This means that they can only be used as directed. Any drugs listed on the jeffers site can be bought withour prescription.
I dont eat eggs while on antibiotics withholding period but I do incubate them.