What causes my dog’s tear stains?

A dog’s tear stains can relate to many factors — blocked nasolacrimal ducts, a greasy or high-salt diet, eye problems, and ear infections among them. Judge the cause from the actual situation and apply targeted treatment. If the diet is greasy or high in salt, switch to a light, low-salt diet promptly. If the tear ducts are blocked, have them cleared. If stains recur frequently, take the dog to a veterinary clinic for a thorough work-up.