What is wrong with my cats? They are sneezing and the one is weezing/coughing.?

Hi I have 2 cats and they are both sneezing. The 13 year old cat is the one that is weezing and kind of coughing... She also wont eat... she will lick at her canned food a little and sip the teeniest bit of water. I am mostly worried about her. The other cat is eating good still. I took them both to the vet and he said its a virus and it will pass. He couldnt give me anything for them. I had them run a bunch of blood tests on the older cat and they all came back good he said. He did say something about giving them l-lysine. I think I will try do that soon. The vet just said it was a virus... and didnt tell me what they could have or anything. Is he right or should I get a second opinion? Please help... thanks.