Do their ears hang low? The Genetics of Dogs’ Adorable Floppy Ears
Scientists are just beginning to understand the signals that determine the length of dogs’ ears
By Heidi Ledford & Nature magazine
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A gene important to human hearing could determine whether a dog’s ears are pendulous like those of a basset hound or short like those of a rottweiler, according to a genetic analysis of more than 3,000 dogs, wolves and coyotes.
The study, presented Jan. 11 at the Plant and Animal Genome Conference in San Diego, Calif., found that DNA variants close to a gene called MSRB3 are linked to the length of the ears in dogs. The results were also published in December in Scientific reports.
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The project was inspired by Cobain, a gregarious nine-year-old American cocker spaniel whose hobbies include morning swimming in a local creek and following people from room to room. One day, Anna Ramey, a student working in a canine genetics lab at the University of Georgia in Athens, looked at her dog Cobain’s long floppy ears and wondered: Why?
She asked her colleagues the question and the project was born. “We realized that people had already studied ear carriage – like pointed, erect ears versus floppy, floppy ears,” says Tori Rudolph, a geneticist in the lab. “But no one had looked at ear length in dogs.”
The length and carriage of a dog’s ears vary greatly from breed to breed. Some of this evolved naturally: Short, erect ears are thought to lose less heat than long, drooping ones, and canines from cold climates tend to have smaller ears than those from warm regions.
But selective breeding has also shaped dogs’ ears. The basset hound’s long ears are said to enhance its hunting acuity by sweeping scents toward its nose, while a German shepherd’s erect ears may slightly improve its hearing.
Rudolph and his colleagues analyzed the genomes of thousands of dogs, looking for sequence differences that correlated with ear length. The research led them to a region of the genome close MSRB3a gene that codes for an antioxidant protein associated with ear size in pigs, sheep and goats. Some mutations in the gene are associated with hearing loss in humans, and previous studies have linked the gene to ear carriage in dogs.
DNA variants discovered by Rudolph and colleagues could strengthen MSRB3 activity, increasing the rate at which cells in the ear proliferate, she says.
The analysis focused on small, single-letter changes in DNA, but some physical variations could be controlled by other types of genetic variants, such as large deleted or duplicated regions in the genome, says Claire Wade, an animal geneticist at the University of Sydney in Australia, who reports that her dog Sage has moderately droopy ears while Phoenix has short, “sticky” ears.
After studying sequence variation in various dog breeds, Rudolph, inspired by her two golden retrievers, Erin and Brooks, now wants to see what can be learned by observing a single breed. “Golden retrievers vary in size and ear length,” she says. “They would be my ideal next step.”
This article is reproduced with permission and has been published for the first time January 13, 2026.
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