Dogs drink by rapidly lapping water upwards with their tongues. The anatomy of the dog's mouth is specifically adapted for lapping, with the tongue forming a curled shape when extended out of the mouth. The lower jaw moves down as the tongue extends, creating a cavity that fills with water. The muscles of the tongue then rapidly snap the tongue back into the mouth, drawing water in with it. This repeated lapping motion creates a continuous flow of water into the dog's mouth, which is then gulped down.
The lapping motion of dogs is also aided by the unique shape of their tongue, which is covered in small, backward-facing spines or papillae. These spines help to create a seal around the water and prevent it from spilling out of the mouth.
In addition to lapping water from a bowl, dogs may also lap water from natural sources such as puddles, rivers, and streams. They may also lap up spilled drinks or other liquids.