It concluded that dogs have more neurons in their cerebral cortex, allowing them to complete more complex tasks.
And boffins say dogs win hands down - with roughly 530million in their cerebral cortex to cats' 250million.
Researchers found that raccoons were an outlier - they have the brain size of a cat, but packs the same number of neurons as a dog.
Did you think cats were more clever and smart than dogs? Dogs, for instance, have more cortical neurons (530 million) than cats (250 million), but also have more neurons than bears, who have larger sized brains.
"I believe the absolute number of neurons an animal has, especially in the cerebral cortex, determines the richness of their internal mental state and their ability to predict what is about to happen in their environment based on past experience", Herculano-Houzel explained. They found that the brain of a golden retriever has more neurons than a hyena, lion or brown bear, even though the bigger predators have brains up to three times as large. The research team not only counted the neurons of these animals but their brain size and body-to-brain size ratios.
An global team of researchers took her work and ran with it to compare the brain size and number of neurons in a wide range of animals, including household favorites like cats and dogs, as well as bears, hyenas, lions and raccoons.
Carnivorans are a diverse group of mammals that includes carnivorous, omnivorous and herbivorous, domesticated and wild species, with a large range of brain sizes.
They also noted that the bear's brain is 10 times larger than a cat's, yet has the same amount of neurons. However, the researchers also discovered that brown bears had almost as many neurons as cats, despite being significantly bigger in size in comparison.
Study leader Professor Suzana Herculano-Houzel admitted she was a "dog person" but insisted that didn't impact her findings. "They have cat-sized brains, but with dog-like numbers of neurons, which places them on par with primates, who as a whole have lots of neurons crammed in small brains".