Dog owners are familiar with their pets’ expressive faces, which seem to show a wide range of emotions. A part of these expressions is the feature we interpret as eyebrows. However, dogs do not have eyebrows in the same way humans do, and something else is behind these communicative facial movements.
The Anatomy of a Dog’s Eyebrows
Dogs do not have eyebrows consisting of fine strips of hair like humans. What people perceive as eyebrows on a dog is one of two features. Some dogs have distinct patches of colored fur above their eyes, called “pips,” which create the illusion of an eyebrow through color contrast. Other dogs have a prominent brow ridge with specialized muscles.
A specific muscle, the levator anguli oculi medialis (LAOM), is present in domestic dogs but not their wolf ancestors. This muscle allows dogs to raise the inner portion of their brow, creating the classic “puppy-dog eyes” expression.
The Purpose of Eyebrow Expressions
The purpose of these eyebrow-like features and their movements is communication with humans. The inner brow raise makes a dog’s eyes appear larger and more infant-like. This expression can trigger a nurturing response in humans, which may have given dogs who produced the movement a selection advantage during domestication. This suggests that expressive brows evolved to facilitate the dog-human bond.
Research supports this theory, with one study finding that shelter dogs who made this movement more often were adopted more quickly. The expression also mimics one associated with sadness in humans, which may enhance the desire to provide care.
Dog Breeds Known for Their Eyebrows
Certain dog breeds are known for their distinct eyebrows, which fall into two main categories. The first includes breeds with specific color markings that give the appearance of eyebrows. Rottweilers and Doberman Pinschers are prime examples, with tan or rust-colored “pips” that stand out against their black coats. Bernese Mountain Dogs also have these markings as part of their tricolor pattern.
The second category includes breeds with bushy or wiry hair that forms a physical, textured eyebrow. Schnauzers are famous for their bushy brows that contribute to their wise and comical look. Many terrier breeds, such as the Scottish Terrier and Airedale Terrier, also have these brows as part of a wiry coat that originally protected their faces.