So they do still have the Tylan 50 available? About a year ago, I was looking for it and could only find the 200. I looked at Elanco's site (it's their product) and they only had Tylan 200 injectable listed. The only Tylan 50 they show is a premix. I'll have to look around again and see if I can find it... hate to buy it online because you don't know what kind of expiration date you will get.
Though I will note that the one time I treated a pea, we were in the middle of a blizzard, temps were dropping like a rock, and my Tylan 50 was expired. I don't even know why I still had the stuff there, it expired in Mar 2004 and this was Nov 2008. I had only had the peas for a week, and the poor thing was obviously in distress. I knew that it was going to be days before we were dug out from the blizzard, so I used the very expired Tylan. One dose, it took about 1.5 days for the swelling to go completely but it did fine. Then I contacted the seller who was honest and informed me that her peas were all having sinus problems, too. She did offer to take them back, I declined. Now that I am raising turkeys again, I'll need to look at having the peas tested for mycoplasma.