How Much Do Dogs Really Remember?

From the first time you met to that awesome game of fetch yesterday, the memories you’ve made with your pup are never ending. But how much of your life together does your dog actually remember? You know they remember you (hello, tail wagging and jumping when you get home!), but why can’t they seem to remember where they left their favorite toy? Like humans, dogs rely on two different forms of memory: short term and long term. But how their memories work is quite different from ours, says Bill Roberts, Ph.D., professor emeritus at the University of Western Ontario.

For starters, your pup’s short term memory is way shorter than yours. In one study that compared the memory span of several species (from bees to big mammals like dogs), researchers found that pups came out on top—but their memory recall was only for about 70 seconds. This explains why your pup remembers exactly where you dropped that dinner scrap two seconds ago, but jumps for joy when you return from getting the mail—they can’t tell if you were gone for two minutes or two hours!

While humans have several forms of long term memory, dogs mainly have two types: associative memory and declarative memory. Associative memory helps dogs remember people, places, and experiences based on the associations they have with them. This is why the minute you pick up the leash, your pup runs to the door with their tail wagging. Declarative memory is the ability to recall facts and events. “It’s almost like looking something up in an encyclopedia in your head,” explains Roberts. Declarative memory allows your pup to remember things like where you store the treats and which area in the park has the best sticks. Declarative memory also includes episodic memory—an area of research scientists have recently begun to study in dogs.

Episodic memory is the ability to recall experiences and specific events in time. “It’s also sometimes called autobiographical memory because it’s tied to specific places, times, and emotions in your life,” explains Roberts. According to a recent study, dogs may share our capacity for episodic memory; however, they may not be able to retain those experiences for very long. In the study, the dogs demonstrated better episodic-like memory after one minute than they did after one hour. So unfortunately, your pup probably won’t remember all those extra belly rubs you gave them this morning.

Roberts also points out that much of your pup’s memory stems from their nose. “Dogs have an extraordinary ability to detect odors and remember them,” he says. “A lot of a dog’s world and their ability to form memories may be based on olfaction.” That makes sense given that dogs have 300 million olfactory receptors (humans only have six million!). You know those heartwarming stories you always hear of dogs finding their way home after several years of being away? It’s because they followed their nose!

The bottom line? While your dog may not remember specific experiences (like the day you met), because of their strong associative memory, they do remember your face and smell—and the fact that they like you and always will!