Can you post some photos of what he looks like now?
What looks like it's eating away at his beak?
If you are going ahead and giving Tylan, then it would be good to give him the correct dosage.
For Tylan50 give him 0.25ml per pound of weight orally, 3 times a day for 5 days.
I can tomorrow, its very dark out at the moment and thank you for the dosage. I've been giving him 0.25 ml if not a smaller dosage. I was very afraid of over dosing him. I plan on stopping the tylan all together because fowl pox isn't affected by it, and Im almost positive that is what he has.
As for the "eating away at his beak" its difficult to explain. Yesterday I had checked up on him in the morning, looking at his face, ect. I wet what looked to be like a scab on his beak, it had that yellowish tint and started to lightly move it off to put some of my wound care cream and a touch of vet rx but when it was sloshing away the "scab" had went deeper into his beak, like it kept going, but as soon as I saw it kept going, I stopped, I didnt want to do anything more. So I put the wound care on it, ect. Cleaned up everything around it so it wouldn't spread.
But I checked on him this morning and he's got another, scabish bump on the bottom of his beak, this also had a yellowish tint. I wet the scab, didnt pull it off and put the wound care and vet rx on it. As for his mouth, its looking better, tad bit of yellow still in there, he still, sometimes, creates "spit" which as I said before, isnt really supposed to happen. Other than the infection or whatever it is, he drinks, eats, crows and dances for me every time I take him out of the cage to treat him and feed him.