Hi there! Excessive tearing (epiphora) in cats isn't normal. Cats can have an occasional bout of discharge, but chronic excessive tearing points to a problem with the lacrimal (tear) ducts.
Overtearing can be caused by blocked tear ducts, insufficient draining (common in Persians and Himalayans), abnormally small duct openeings, or scarring of the ducts due to conjunctivitis in the past. Also epiphora can result if there is injury or irritation to the cornea, keratitis, conjunctivitis, and a few other eye issues.
Typically, epiphora is a clear or reddish/rsut colored drainage, whereas an infection would be greenish, yellowish or whitish discharge. With any eye problem, we always suggest a veterinarian looks at your animal's eye because some of these eye issues, if left untreated, will lead to vision loss. So, I would definitely consider seeing a vet about this if if were my cat. There may end up being no treatment necessary, but it is always best to be safe instead of sorry.
I am including a couple of links for your information:
http://www.petplace.com/cats/epiphora-in-cats/page1.aspx
http://www.gopetsamerica.com/dog-health/eye-problems.aspx
Best of luck!
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