By Helen Anne Travis
Dogs are amazing creatures. They’re able to lead blind people through bustling streets, bring errant sheep back to the herd, and can be trained to do everything from fetch a ball to detect cancer.
But how exactly do dogs’ minds work? And how do their brains compare to humans’ and other animals’? We sat down with some of the country’s top veterinarians to learn more.
Do Dogs Think?
“Oh my gosh yes,” says Dr. Jill Sackman, a clinician in behavioral medicine and senior medical director of BluePearl Veterinary Partners’ Michigan hospitals. Dr. Sackman has a PhD in molecular and cellular biology. “They probably have the level of cognition of a three to five-year-old human.”
Dogs can tell we’re trying to show them something when we point at an object. They can evaluate whether one bowl has more food than another. They respond to familiar voices, and are excellent at determining whether someone is friend or foe.
Many dog owners will say it’s the dog who has them trained to be fed and let out at the same time everyday.
Obviously something is going on in their furry heads. They’re capable of making associations and reacting to stimuli. But what they think about, and how they interpret the information, is still a mystery.
“Just as it’s impossible to read another person’s thoughts, it is impossible to speculate exactly what a dog is thinking,” says Dr. Rachel Barrack of Animal Acupuncture in New York City.
What Does A Dog’s Brain Look Like?
All mammals have similar brain structures, says Dr. JP McCue, a board-certified veterinary neurologist at NYC's Animal Medical Center. The hemispheres, lobes and parts of the brain have the same names and the same basic functions.
But in dogs, the parts of the brain associated with smell show they have incredibly sensitive noses. More so than other companion animals like cats and ferrets.
“They use a much larger portion of their brains for analyzing smells,” says Barrack. “It is also presumed that dogs associate scent with memories, which is why they can be trained to sniff for bombs and drugs.”
How Do Dog Brains Differ From Human Brains?
Not by much. In addition to being structurally similar, MRI studies have shown that the same sections of our brains light up when we’re exposed to various stimuli, says McCue.
Man processes fear, memories and spatial awareness in the same way as his best friend. Scientists have also suggested that certain cognitive skills are clumped together, just like in human brains. (For example: if you’re good at math, you’re likely good at problem solving.)
“We’re finding the same is true with dogs,” says Sackman. “Certain skill sets come together. A dog that is fast and accurate in one task has the capacity to be fast and accurate in another task. That would lead us to believe that the heritability of intelligence and cognition is in some degree similar in dogs as it is in people.”
Like humans, older dogs have a propensity to develop a condition that is similar to Alzheimer's disease. Because of the semblances between their brains and ours, dogs are used to evaluate the impact of nutrition and drugs on the brain’s aging process, says Dr. Sackman.
But we’re not exactly alike.
Dogs’ brains are smaller than ours when compared to overall body size. Our brains have more folds, meaning more surface area. And our prefrontal cortex—where higher level processing and thoughts occur—is more developed than dogs’, says McCue.
Can Dogs Understand Humans?
One of the theories explaining why dog and human brains have so many similarities is that we evolved together.
Dogs are the oldest domesticated species. They’ve been interacting with people for millennia, and as a result, have learned how to understand and communicate with us better than any other species. Their strong sense of observation allows them to pick up hints in our body language, smells and the tones of our voices.
“I think people react to those types of signals on a subconscious level, but dogs react to them on a conscious level,” says McCue.
One possible story goes something like this. Dogs followed us into our first cities and camps to take advantage of the food waiting for them in our early garbage piles. Those that were less fearful of humans were rewarded with more food. And those that could pick up on human signals—like pointing, and being told to stay and sit—were given even more.
Dogs returned the favor by helping early humans with hunting, and protecting them from other wild animals.
“Some [papers] I’ve read say humans have been able to evolve and survive because of our partnerships with dogs,” says Sackman.
Do Dogs Have Feelings?
“Absolutely,” says McCue. Dogs process sensation and emotion much like we do.
Studies have shown they’re capable of feeling optimism, anxiety, happiness, fear and depression. They get jealous when another dog gets a bigger reward for the same behavior, and their brains respond to antidepressants like Prozac. There is also evidence that dogs who experience traumatic events experience symptoms of PTSD, just like humans.
When observed in an MRI, dogs’ brains react similarly to humans’ when exposed to emotional stimuli like the sound of a baby crying. They also experience pain like we do.
“Pain is something we experience emotionally, it’s not just a prick on the finger,” says McCue.
What Is My Dog Trying To Tell Me?
Dogs can certainly understand us. But do they also try to talk back? Veterinarians say yes.
“Dogs don’t have words,” says Sackman. “They communicate through body language and they make sounds that give us a wealth of information about what they’re thinking.”
A dog turning her head away or licking her lips is telling us she’s nervous, says Sackman. If we humans respond with a hug, we’re acting like primates. Primates hug; dogs don’t. “A lot of dogs don’t like it,” Sackman says.
There’s still a lot to learn about canine cognition. Scientists are constantly developing new ways to study dogs’ brains. But MRIs and research papers can only tell us so much.
“Until dogs can find a way to talk to us, there’s a lot we won't know,” says Sackman.