Most dogs are friendly towards the people they see all the time (their families.) But if a family friend comes over and the dog takes a liking to them, and that friend doesn’t come back for a while, will the dog remember them when they come back?
My dog chihuahua remembers my friends even if it is a year between visits. He is aggressive toward any stranger but once he knows you he will greet you with extreme enthusiasm. One friend he hadn’t seen in almost two years and got excited at the sound of his truck pulling up. Dogs are not the only animals that do this, geese can also remember you for quite some time.
We had a carpenter do extensive things for us. He was here almost every week (and most days of the week) for more than a year. He came back more than a year later and our dogs greeted him warmly – which they don’t do for strangers.
Three years back, I had a niece living in town taking a Master’s degree. I walked my dog over to her house, a few blocks from here, maybe 3 times during that time. He wasn’t fed anything, we didn’t stay longer than a few minutes each time.
My dog still pulls wildly on the lease when we pass her former house. Now she was often at my house, and the dog loved her, I’m certain. But three years later? Under four feet of snow? What trace could there still be?
I can only assume he must remember, both the place, and the connection to someone he no longer sees but rarely.
Seems like it would depend on the dog’s intelligence and personality. I’ve known dogs who were a bit hazy on non-household-member humans they saw regularly.
At least sometimes yes.
Years ago my college housemate had a little beagleish dog. I decided that I would teach her to “shake hands” and with enormous levels of repetition, was successful in doing so. Two years after I graduated and moved to another state, I visited my friend at her home. As soon as I got out of the car, the dogs came running up to see us. When the beagle-dog saw me, she immediately sat and offered to shake! My friend swore up and down the dog was not in the habit of offering to shake with everyone, in fact, she had not reinforced the command much. The dog had an association between me in particular and “shake hands.” Now of course I lived in the household with the dog over a period of years.
I think smarter dogs and cats can remember infrequent visitors they’ve never lived with, but it takes several or even many visits before it takes hold. I feed my friend’s cat when she’s away but other than that I’m rarely at her house. It probably took 6 or 7 times of me feeding her cat, over a couple of years, before her cat decided I wasn’t a stranger and thus it was not necessary to hide.
Some dogs do remember people, and so do some cats. On the other hand, I have one cat who is so stupid that she will cry because a door is most of the way closed, at the hinge side of the door. She can’t remember which side of the door will open! Another one of my cats definitely remembers my daughter, and runs up to greet her when my daughter comes to visit.
Intelligence and memory in dogs seem to vary widely between individuals.
Thurber once commented on stories about dogs that returned to their owners over thousands of miles, contrasting those tales with the litany of lost dogs who apparently couldn’t find their way back from the next block (assuming they wanted to come home).
I had an older rescue spaniel that, if let out in the front yard, got confused about how to circumvent a low ornamental fence that she’d walked around just minutes before, and would unhappily sit in front of it until rescued anew. This same dog once calmly tolerated a guest on Thanksgiving who bore a vague physical resemblance to Mrs. J. Toward the end of the visit she suddenly started barking at the woman (only belatedly realizing this was a stranger). The dog would probably have remembered us after an absence of a week or so. Longer than that, I’m not sure. 
We had a dog when I went away to college. She went blind while I was away. When I returned, she started barking at me (she barked at all intruders) until I spoke, and which point she went into full tail wagging mode. So she remembered.
Our cat remembers a certain friend of ours who we see every 5-6 years or so. She teased the cat a lot when he was a kitten, and whenever she returns, he hisses at her. He doesn’t hiss at anyone else.
My sister had a malamute. The dog could not be confined and roamed the neighborhood, she was sweet and most of the neighbors tolerated her pretty well.
One day her next door neighbors had guests who lived in the same town I lived in and they were friendly towards the dog.
One day when the dog was roaming one of the neighbors who didn’t know her kind of flipped out because this big scary dog was running around and might attack his grandchildren. Animal control got called, my sister was afraid they would take the dog so she drove her to my house and put her in my fenced in yard. (without telling me and I wasn’t home at the time)
I come home to an open gate, like I said the dog couldn’t be confined. She got out and then went several blocks up the road to the friends of my sister’s next door neighbor and scratched on their door. They remembered her, called their friends, who called my sister and she had to go get the dog.
The dog had only met these people once, yet I guess she remembered their scent enough to know who they were and where she had met them? She was exceptionally smart and a really good dog. Just a little intimidating because of her size.
Oh yes! My little Papillon Cricket absolutely LOVED my friend Pat, who lived in Virginia, and I am in Indiana. When Pat came here to visit, Cricket was HER dog. Probably a year and a half later, I drove to Virginia to see Pat, and took Cricket with me. She was in the back seat, and when Pat opened the back door, Cricket gave an almost human scream of pure delight and launched herself into Auntie Pat’s arms. She definitely remembered.
Blackjack only needs to meet someone once and he’ll remember. He also remembers other dogs after a single meeting. He’s a pretty smart dog, I’ve had others who were less than brilliant. I’d guess they go more by scent than sight in identifying people.
My wife gets home every day, and our dachshunds go crazy. Like, dogs welcoming soldiers crazy. Whining, jumping, barking, licking- absolutely nuts.
My best friend only comes by our place every 4-5 months or so. He gets the same treatment.
The dogs recognize all of our extended family members; cousins, grandma, etc, but they just get some barking and jumping. Only A.J. gets the full frenzy like my wife. Dogs is funny that way.
I think scent has a lot to do with it. In humans, scent is powerfully associated with memory; who has not had a familiar smell (fresh-baked cookies, a Christmas tree, oranges, etc.) instantly evoke a mood or memory?
Dogs not only have vastly better sense of smell than we do, but more of their brain is devoted to processing that input. I think that dogs do remember, but especially when scents are involved. They know us by scent more than by sight or sound.
Anecdote: We had downstairs neighbors for a few years, whom our dogs encountered casually on walks from time to time (although I’m sure the dogs also heard and smelled them in the vicinity more often than that. The husband in particular occasionally stopped and patted the dogs.
Then they moved away, but kept their place to rent out. Two years later, the man returned to fix up the condo after tenants had moved out. I saw him and he asked about the dogs…and then I realized he was lingering to talk about them, and probably wanted to see them. So I brought them out.
It was as if he had been their best friend ever, freshly returned from a Nazi concentration camp, somehow alive against all odds. They were all over him with “OHMYGODITSYOU!” enthusiasm.
Keep in mind this is someone with whom they barely had a relationship before he moved away.
Certainly they do, As do house cats.
Even bigger cats! A male lion cub was raised by two men, and then transported to Africa and released in the wild. They visited a year later, and This link is a video of that reunion. The lion quite clearly remembers them.
My friend has four cats, and two of them are friendly with me. I don’t know, though, if they’re naturally friendly or if they do indeed remember me.
I don’t even have to press the link–I know the one. It has made me weepy more than once.
I last saw a dog (Border Collie) in Lafayette IN in 1972. I had lived with it for a few months (the house was a zoo).
In 1976, I had reason to look up his owner (I was to transport a 3rd party’s cats to my destination - and the dog’s owner had said cats).
We are now in S. Carolina - the dog went nuts when I walked in the room.
Add another vote to the yes column. My dog remembers my daughter who only comes back once a year now. And she remembers anyone who gives here a treat in the field forever, and in fact goes for the one person of a couple who feeds her.
I’m sure some dogs do get lost, but my old border collie/cocker mix used to like to go to another elementary school, and when we didn’t want to he’d pull at every cross street leading there. He took me on a short cut to yet another school which my wife took him on and which I didn’t even know. He’d never have gotten lost, though he might have spent some time exploring.
I saw some friends for the first time in about three years just recently. They have a chihuahua (Miguel) who is normally very territorial- he’s a great dog once he gets to know you, but he’s very distrustful of strangers and it takes him a while to get over his nervousness. He doesn’t bite, but he barks and runs away. And then barks some more.
Anyway, like I said, I hadn’t seen my friends (or their dog) in about three years. As soon as I walked into their house, though, Miguel all but leapt into my arms, and wouldn’t leave my lap the entire night. He definitely remembered me.