I have had good results using colloidal silver in my cattery. At the first signs of running eyes, I use several drops- 3-5 times a day, directly into the eyes of the kittens. A week or less is all that I usually need to do and the virus is gone. If nasal symptoms appear, I put a drop in each nostril. I also put a dropper full into the cats water dish, especially in warm weather. It helps keep bacteria down and I believe, strengthens their immune system. What other product is so safe, yet kills virus, bacteria, fungus,yeasts & molds, without harmful side effects or built up resistance ????