I belive the withdrawl time for terramycin is 4 days. After that, you can eat the eggs. If it is a coccocidant like amprol, then there is no withdrawl time.
For future note. If they are just sneezing, and you don't know the cause, giving antibiotics (that only affect bacteria and do NOTHING for virusus or irritants of respiatory system) can give you and the world more problems in the future. If you know it is a bacteria causing the problem, do it, else, don't.
The over use and incomplete dosages of antibiotics is why there are so many resistant strains of bacteria we can't kill anymore. Antibiotics kill the weak bacteria and if a few strong ones live, can overpopulate and cause a stain that can't be battled. This resistance will lie in the transferable genes of the bacteria and it can trade it with prevously susceptable bacteria. So in effect, you can innocently breed hundreds of bacterium that you cant do anything about when they take over your immune system. On a large scale, something like 2/3 of hospital patients die of secondary infections due to resistant strains of bacteria.