Excessive tears in themselves are not a danger to a cat's health. However, it is important to determine the underlying cause of the tearing because some things that can cause the eyes to tear can also be irritating and painful.
Herpesvirus, Calici and Chlamydia are the three most common upper respiratory infections (URIs) in cats. This article includes an easy to use chart to help you determine which if these upper respiratory infections your cat might have.Â
Pyothorax is a bacterial infection that develops in the chest cavity of the cat and results in pus accumulating in the area between the lungs and the chest wall. It is can be fatal if not treated aggressively.