I had pinkeye once. I opened up a minocycline capsule and mixed the yellow powder with a few tablespoons of water and put a single drop of it in my eye. It cleared up over night!I am taking a goat to the vet today,, dealing with what I think is Pinkeye but I want to be certain
Disclaimer: proper medical attention was not available to me at that time so maybe your vet has better stuff. Minocycline has no shortage of side effects (even when properly used), many are serious, but it sure worked well for me.