If a dog keeps swallowing saliva and licking its tongue, it may be caused by thirst. If the dog's body is dehydrated, the dog will swallow saliva and lick its tongue to keep the tip of its nose moist. At this time, it is recommended that the owner replenishes the dog's water as soon as possible, and should also provide the dog with sufficient water sources at ordinary times.

When a dog has an upset stomach, he will feel vomiting, accompanied by symptoms such as swallowing saliva, licking his tongue and nose, and similar symptoms of hiccups. It is recommended to consult a pet doctor in time.