How to keep a dog free of tear stains?

Tear stains may come from salty food, blocked nasolacrimal ducts, inverted lashes, eye infection or ear disease; see a vet for the cause. Switch to lower-salt food and increase water if the diet is salty. For blocked ducts or inverted lashes, surgery is the fix. Red, inflamed eyes need eye drops and anti-inflammatories, severe cases a vet. Ear mites or infection need treatment, and clean the ears often to avoid tear stains from facial-nerve pain.