Many of the breeds that have an “up face” including persian cats often have more prominent eyes, and the eyelids tend to be stretched across the eyes which can cause the tear duct to be partially or completely blocked.
This the most common reason, but does not always apply to every dog. Allergies can cause excessive tearing, as well as inverted eyelids or eyelashes and is surgically correctable. Red eyes and or if there is any yellow or green discharge coming from the eyes is an indication that an eye infection is present and needs to be treated with an antibiotic.
Long hair can act as a wick also, drawing tears from the eyes. Putting your Shih Tzu’s hair in a top knot or trimming the hair around the eyes can help prevent the hair from acting as a wick.
If you are not familiar with pulling the hair up into a topknot or don’t know how, this website has an excellent instructions and illustrations on showing how to. Scroll down midway till you get to “Casual Shih Tzu Top Knots”
http://www.shihtzu-gulfcoast.com/grooming.htm There are products available that can remove the stains, and these work fairly well. Great care must be taken that you do
NOT get these products in the eyes as they can cause irritation
DrsFosterSmith has very good products and is a reputable company to order items from. If you are not comfortable ordering online, there is a toll free number in which you can call 24 / 7.
http://www.drsfostersmith.com/Product/prod_display.cfm?pcatid=584&rel=1Customer service
http://www.drsfostersmith.com/general.cfm?gid=314Or if you like, petsmart also has a product to remove stains called “tear clear by eight in one”
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