Human meddling has manipulated the shapes of different dog breeds’ brains

Distinct shapes of pooches’ brain regions aren’t solely due to the animals’ size or head shape


Scans from 33 dog breeds revealed variation in brain regions involved in scent hunting, guarding and companionship.

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Dog breeders have been shaping the way the animals look and behave for centuries. That meddling in canine evolution has sculpted dogs’ brains, too.

A brain-scanning study of 62 purebred dogs representing 33 breeds reveals that dog brains are not all alike — offering a starting point for understanding how brain anatomy relates to behavior. Different breeds had different shapes of various brain regions, distinctions that were not simply the result of head shape or the size of the dogs’ brains or bodies, researchers report September 2 in the Journal of Neuroscience.

Through selective breeding, “we have been systematically shaping the brains of another species,” Erin Hecht, an evolutionary neuroscientist at Harvard University, and colleagues conclude.

dog brain comparison
Certain brain regions take on a different shape in a basset hound’s brain (left) than the brain of a border collie (right).Marc Kent & Erin Hecht

The MRI scans were taken of dogs with normal brain anatomy at the Veterinary Teaching Hospital at the University of Georgia at Athens. While the study wasn’t designed to directly link brain shape to behavior, the results offer some hints. Researchers identified groups of brain areas, such as smell and taste regions, that showed the most variability between breeds. Those groups are involved in specialized behaviors that often serve humans, such as hunting by smell, guarding and providing companionship to people, earlier studies have suggested.

The authors assumed the dogs in the study were all pets. It’s possible that dogs extensively trained for specialized work — such as sheep herding, bomb detecting or guiding the blind — might have even more distinct brains.

Laura Sanders is the neuroscience writer. She holds a Ph.D. in molecular biology from the University of Southern California.

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