Hi mochamoo
I think adding L-Lysine to your cats food would be the best option. It stops the symptoms as long as it is used every day, I use it for my cats just as an immunity booster & have read about it helping with the herpes virus. I think I got mine from iherb, found it on the net as really you need just the L-Lysine as I have been informed some of them can contain other things harmful to cats. The product from iherb is a powder & has nothing else in it so it is safe for cats. Here is the link
iHerb.com - Vitamins, Supplements & Natural Health Products look under L for the L-Lysine under now foods think there it is the 1LB in powder form. Hope this helps you