It’s long been known that the smelling capacity of a dog is off the charts compared to that of humans. Dogs have over 40x the amount of smelling ability in their nasal passages, with a more significant part of their brain devoted to analyzing smells. It’s truly unique when you think about it.

It also means if you find your socks smelling a little raunchy, your dog will most likely be silently begging you for a dog-fitted gas mask to continue breathing. Whatever you smell, the dog will sense it at a 40x level or higher depth and dimension than you.

How long does a dog remember a scent?

Dogs can remember a scent for their entire life. A dog’s memory is set up to remember places, people, events, and other things associated with both a smell and a positive or a negative emotion. Using these two things, all scents are cataloged in their mind: the neighbor’s cat, the newspaper delivery person, the mail delivery person, the vet, and so on.

Do dogs remember you by smell?

Yes. Dogs remember people they’ve come into contact with by smell and by a positive or negative emotion. Dogs can remember people who have loved them and treated them well and people who have mistreated them.

Depending on how long ago they saw this person, they may not remember the exact specifics of the interaction, but only that their “smell log” says that this person was good to them, and they had good feelings. Once they recognize this, the dog starts wagging its tail, whining, and wanting to show other affection or displays of happiness.

It’s the same for someone who may have treated them negatively consistently. Perhaps the neighbor taunts the dog through the fence while you’re away at work, and then, when the neighbor comes to visit your home, the dog will behave in a defensive or a scared manner around the neighbor.

How long do dogs remember you for?

Dogs can remember you for their entire lives as long as their smelling capacity remains the same. Many things in a dog’s life are surrounded by and pinpointed through one or more smells. Sometimes, like memories we have, we get triggered when a particular situation, sound, smell, or emotion occurs.

Perhaps a memory appears we don’t even remember having until it surfaces. A dog experiences the same thing. Only a dog won’t remember the actual happenings for each situation they encounter. They will remember good or bad only.

One rescue dog that was reunited with its owner only remembered the old owner once the owner both called the dog by a unique nickname in a particular tone of voice along with smelling her. Once the dog had this triggered by their “smell log” (long-term memory), the dog began to whine and was uncontrollable with emotion. Both dog and owner went home happy as though they had never been apart.

How long does a dog remember you for after you’ve had to give it up?

If a person has to give up their dog for adoption or rehome it, the dog will still remember that person for its entire life. However, their memory gets shoved far back into the recesses of the dog’s long-term memory.

After one to three years, with no contact from the owner to the dog’s new family, the dog will “forget” the old owner. But not really, not ever. All it will take is a smell from an old shirt, a sound clip, or a familiar food or situation to make them immediately remember again.

Once the dog has had a chance to form new routines and create new pleasure pathways with the new owners, they are “happy” and adjusted again. They do not dwell on the past, only focusing on the present and a “What’s in it for me right now?” mentality. Dogs don’t feel guilt ever. 

Do dogs recognize people’s faces?

Yes. Dogs remember people’s faces as long as their vision is not failing. If a dog sees someone from their past or thinks they see someone from their past (the same manner of dress with the same body build, height and weight, etc.) from a distance, they may react positively or negatively based on their “smell log” memory and what it says.

If the person comes closer and it turns out it is not the dog’s owner, then the dog will proceed to treat the person like a stranger. Dogs look for facial cues to help them recognize people they love.

For example, if a person wears glasses, the dog will look for the correct shape of glasses over the person’s face. This facial recognition capability can get a little skewed for the dog and confuse them if they smell their owner (correct smells) but suddenly see their owner without a beard and mustache or suddenly wearing a baseball cap when they never wear one.

Since the facial recognition cues and the smells do not match what they have stored for analysis, sometimes they will bark or act fearful until the facial lines are corrected (hat is removed) or until the owner speaks, confirming they are who they say they are.

How many smells can a dog remember?

Dogs smell hundreds of different scents daily, depending on their life, and each dog smells an entirely different set than the dog down the street. Which ones they actively remember are based on how many different smells are continually present and active in their current life.

In addition, because of their ability to store memories in their long-term memory with the “smell log,” they can remember a smell and its related emotional association. Still, it may not be triggered and brought to the forefront of their mind for a very long time.

Dogs can be trained to recognize scents. To be the most effective in this training, it’s best to only train them on a range of smells of one thing or a group of related items. For example, a dog can be trained to sniff out bombs, drugs, or cancer. Other dogs are trained to detect distressing emotions and anxiety in a person based on the chemicals they now emit from their pores. This training does not rule out their capacity to analyze and log other smells regularly.

Do dogs remember siblings?

Yes. Dogs can remember siblings under certain circumstances. Dogs can remember their siblings later in life as long as they spend at least 12 weeks together after birth. Some studies say that they can recognize their adult siblings up to two years later. Other people you ask may have different experiences where a dog might remember their siblings, or the mother remembers their pups after an even more extended period.

Do dogs remember places?

Yes. Dogs remember places the same way they remember people or events. They do this through their “smell log.” Everything is logged with a smell and a positive or a negative emotion. So, if the place is visited regularly, the dog will recall its memories of the site faster.

For example, if you visit the dog park weekly, the dog will remember the scent of the dog park as it approaches it the following week. One owner described their dogs getting excited upon returning home approximately a mile away from their home. If the windows were down, the dogs could sense they were almost home due to the smell of the neighborhood. 

On the other hand, a dog may not remember a place quickly if it only sees or experiences it one time. Because of how the smells are logged, if there was a neutral reaction to the site, the place may be placed further towards the bottom of “remembering” compared to areas with positive or negative emotions.

If the dog only visits a place once in a while, once a year, for example, like the vet’s and the dog had a negative experience, they may show nervousness as they approach the facility once again. You’ll also find dogs who spend time in and out of dog pounds will react in similar ways when they come near another dog pound or an animal control officer.

Author

I created and currently manage Pet Dog Owner, the website you can go to when you have questions about your dog's behavior. It is my hope that you find Pet Dog Owner to be a helpful resource. It is also my hope that it will help you to improve your relationship with your dog. You can read more about me and my website here.