Excessive eye tearing in dogs, also called epiphora, is the result of an overflow of tears from the dog's eyes. In certain breeds of dogs (e.g. poodles, spaniels, malteses, pugs, etc.), eye tearing is a natural condition. The bronze staining of the hairs around the dog's eyes is due to a compound in the tears called porphyrin.
More often than not, eye tearing is of cosmetic concern, although it can also be a sign of ocular pain. For example, if there is a corneal ulcer or inflammation of the eyeball, excessive tearing can occur. Excessive tearing can also result when aberrant hairs touch the eyes or the tear film. A misplaced hair can act like a wick and draw tears onto the face. There can also be a problem with the tear drainage apparatus. For example, the lower eyelids or tear wells may be too shallow, causing tears to spill over. The tear ducts may also become blocked and unable to properly drain away the tears.
If your pet experiences excessive tearing, you should have your veterinarian carefully examine his or her eyes to make sure that the problem is not simply a cosmetic one. If your veterinarian finds no medical basis for the excessive tearing, you can try several of the over-the-counter tear stain-removal products. You may need to try more than one type before getting results. Usually, wiping the face twice daily with a wet face cloth is sufficient.