Eye discharge, flattening of the fur around the eyes.  Drooling down the chin and chest.  Unable to eat normally/lack of appetite.  Pawing at the mouth.  Quidding (dropping food from the mouth when eating).  Weight-loss.  Constipation.

Possible Causes

Genetic causes and/or unsuitable diet.  Poor husbandry.  Possibly the biggest killer of domestic chinchillas.