Many drugs and diseases are associated with excessive saliva production. In other cases, the weak muscles can also cause chronic drooling. The diseases associated with excessive salivation are: - Rabies - Amyotrophic lateral sclerosis - Cerebral palsy - Gastro-esophageal reflux disease - Parkinson’s disease - Macroglossia - Stroke - Intellectual disability - Poisoning Reference: https://www.webmd.com/oral-health/what-is-saliva Image via: https://dentaleducationhub.com/excessive-salivation-an-easy-and-instant-guide/