Many people wonder whether dogs possess structures similar to human lips, given their unique facial expressions and eating habits. While dogs do have structures around their mouths that serve analogous purposes, these are distinctly different from human lips in their anatomy and function. Understanding these differences provides insight into how dogs interact with their environment and communicate.
Understanding Canine Mouth Anatomy
The structures often referred to as a dog’s “lips” are scientifically known as flews. These are the loose, fleshy folds of skin that hang over a dog’s teeth and gums. While the lower lip is typically just called the lower lip, the upper lip is commonly referred to as the flews. The appearance of these flews varies significantly across dog breeds, with some breeds like Bloodhounds, Basset Hounds, and Saint Bernards having particularly prominent, pendulous flews.
Dog flews are composed of more rigid muscle tissue compared to the soft, pliable tissue of human lips. They form a sort of seal around the mouth and are connected to the gums. Some dogs also feature internal folds or ridges within their flews, known as ruga, which play a part in their oral functions.
The Many Roles of a Dog’s Mouth Structures
A dog’s flews perform several functions. They help dogs hold and manipulate food, gripping it to prevent slippage during chewing and aiding in the channeling of saliva for digestion. These structures also contribute to a dog’s ability to drink, helping to create suction for efficient lapping of water.
Beyond eating and drinking, flews serve as a protective barrier for the teeth and gums, shielding them from dirt, debris, and potential injury. They also play a role in canine communication and expression. Dogs use their flews to convey emotions, from a relaxed, slightly parted mouth indicating contentment to pulling them back in a snarl as a warning sign. For certain breeds, such as scent hounds, flews assist in trapping and concentrating scent particles from the environment, enhancing their tracking abilities.
How Dog Mouths Differ from Human Lips
The structures of a dog’s mouth diverge from human lips in several ways. Unlike human lips, which feature a distinct, often reddish vermilion border, dog flews typically blend in color with the surrounding fur and lack this sharp demarcation. This absence is due to structural differences in the skin and underlying tissues.
Human lips possess fine motor control that allows for complex actions like pouting, puckering, or articulating speech sounds. Dog flews, by contrast, lack this level of dexterity and are not adapted for such nuanced movements. While dogs can convey expressions, they cannot form words or make the precise movements humans use for speech. These differences highlight the evolutionary paths of each species, where human lips developed for intricate vocalization and expression, while canine mouth structures evolved for functions like protection, food manipulation, and scent detection.