The problem with the herpes virus family, as many humans with herpes know, is that it is the gift that keeps on giving. The immune system of humans and cats cannot clear the infection and rid the body of the virus. The virus lays dormant for periods of time and then starts reproducing causing flare-ups. Periodic “cold sores” on the lips of humans is a common herpes flare-up. In cats, seasonal sneezing and conjunctivitis coincide with seasonal changes in spring and fall or during stressful holiday periods like Christmas. Seasonal changes and stress result in an increase of corticosteroid hormone released into the blood, which suppresses immune function and promotes shedding of the latent herpes virus. It is during these periods of flare-ups that veterinarians recommend the use of L-Lysine to decrease viral reproduction and shedding.