Flushing the Tear Ducts
Flushing the tear ducts performs two functions that may reduce or remove tear staining: it clears out any bacterial build, and it stretches open ducts that are shallow, closed or unable to properly drain.
Antibiotics
Dampened facial hair can be a home to bacteria and yeast infections that will result in excessive tearing. Prescription antibiotics are needed in these instances.
Grooming
Use a moist cotton swab to loosen accumulated matter around the eyes, particularly in the corners. Trimming the hair near the eyes may also help as excessive tearing may be caused by eye irritation from long hair.
Fleas nestled around the eyes often cause excessive tearing as well.
Diet
Dogs should drink filtered water as water that is high in minerals can cause excessive tearing. Adding a small amount of vinegar to your dog's drinking water may also help.
Additionally, many food dyes induce tearing and are found in a long list of commercial dog foods.
Angels Eyes Tear Stain Remover
Angels Eyes, a commercial product that eliminates tearstains, functions by binding porphyrins to prevent them from reacting with light to create the reddish brown stain around the eyes. It is considered very safe, with no side effects even when overdosed.
While excessive tearing is a problem that small dog breeds commonly encounter, it can be treated and possibly solved by these treatments.