All 5 cats have been to the vet this week. All 5 have an URI infection. I just spent $300 for everything from my Vet. All 5 cat got the Convenia shot and a recommendation to keep them on the "Lysine" regular diet. I have bought the 1 pound size on the internet for cheap. I am worried about other money issues as I am not rich here. My cats are from 8-15 years old. What are your thoughts?