Cat eye and colds

Question
I adopted a cat from my local animal shelter on April 19th.  There had been a respiratory infection going around so when I noticed his eye leaking and he sounded like he was snoring and was sneezing I took him into my local vet.  This was around April 21-22nd.  She gave me some drops for his eye (Gentocin)and told me the cold should resolve itself.  Neither one has cleared up yet.  His eye seems  to be ok as long as I am still putting the drops in but as soon I stop it starts leaking again within a day.  The sneezing did seem to clear up and so did the snoring but I noticed it has started to get worse again.  I have another cat and she has not displayed any of these symptoms.  Could this really be a cold and an eye infection from the cold (this is what my vet told me) if my other cat after almost 2 months of exposure has not caught it?  If so should his repiratory infection not be cleared up already?  I need to know what to do.

Answer
This is most likely due to a herpes virus infection, which is one thing we do vaccinate against.  Many cats from shelters have herpes-related URIs as they often show up during periods of stress.  I would recommend a course of oral antibiotics as most likely there is secondary bacterial infection causing the sneezing and eye infection.  If your cat is cooperative, you can also give 500 mg of L-Lysine twice a day and 100 mg of Ester C twice a day...the lysine helps stop replication of herpes and Ester C helps the immune system.