Hi and welcome to HCM,
is caused due to less clearence of saliva and is called sialorhea, Increased salivation can have number of reasons like mouth ulcers,upper respiratory tract
infections, tonsillitis , pharyngitis
, oral mucosistis, nasal drip and allergies, mercury toxicity, medicines like rabeprazole
, neurological disorders of leads to drooling of saliva .
According to the underlying cause and diagnosis, exact treatment can be done.
Fowl smelling saliva indicates infections like retro pharyngeal or tonsillar abscess or accumulation of bacterial plaque and calculus in the mouth. so i suggest you to consult a physician for clinical examination and exact treatment.
Maintain good oral hygiene
, atropine sulphate helps in reducing salivation but can be used only under medical supervision. take care.