I have a feral cat that is not totally tame yet…meaning I cannot pick her up or pet her for very long. Well, she ended up having a conjunctivitis episode. I did not know she had this until recently. This happened on a weekend about a month ago. She was miserable. I was quite upset because I could not put drops in her eyes, which is the usual medication for this and I could not catch her to take her to the vet. So I did some research on the Internet and found that l-Lysine given orally can help this. It may take longer, but it does work. So, this is what I did. I bought the l-Lysine capsules (500 mg) and mixed the contents of one of these in wet cat food and fed it to her at least once a day. The original article I found suggested this be done twice a day. I could not find that article again but I did post some things below as a start for anyone else who may have a cat that they cannot give eye drops. I spoke with my vet about it and he said you could do this. But, since I am not a vet or doctor, etc., so please check with your vet before you try something like this with your cat. It did seem to work for my cat. After about 3 days of this at least once a day, she was much better. I gave it to her for a week once a day and she was over it. So far it has not come back but I am ready for it when and if it does.
Here is one link to a site that gives you some info on this: