Wild Dogs Have Muscles for ‘Puppy Eyes,’ Suggesting the Cute Expression Did Not Evolve Just for Humans

Puppy-dog eyes are irresistible. Many dogs have mastered this iconic, sad-sweet expression, which they use to look up at their human owners while begging for treats or asking to hop onto the furniture.

But pet dogs are not the only canines capable of pleading with their eyes, new research suggests. African wild dogs (Lycaon pictus), also known as painted dogs, have the same well-developed muscles around their eyes as their domesticated cousins do, according to a recent study.

The study focused on African wild dogs, highly social animals that live and hunt in packs on the African savanna. These creatures weigh between 40 and 79 pounds, and they have large, rounded ears that stick straight up. Their painted dog nickname comes from their distinctive fur, which grows with splotches of black, brown, tan, and white.

Researchers dissected a deceased adult male African wild dog and found well-developed facial and ear muscles, as well as the two types of eye muscles responsible for creating puppy-dog eyes. These muscles were similar in size to those found in domestic dogs.

The discovery challenges the idea that puppy-dog eyes evolved solely for human communication, as African wild dogs likely use their eye muscles to make facial expressions as a form of silent communication with each other while hunting on the savanna.

Further research is needed to explore how other wild canines, such as foxes and Asian wolves, use their facial muscles in communication.