neurogenic damage in epiphora
Imperforate lacrimal puncta are an infrequent cause of epiphora in young dogs. In foals, atresia of the nasal (distal) end of the nasolacrimal duct is a common cause of early epiphora and chronic conjunctivitis. In calves, multiple openings of the nasolacrimal duct may empty tears onto the lower eyelid and medial canthus, causing chronic dermatitis.