The bond between dogs and their owners is often incredibly strong. Many dog owners consider their dog to be a member of the family. So when dogs are separated from each other, whether it’s sibling dogs from the same litter or dogs who have lived together in the same household, a natural question is whether those dogs will remember each other if reunited after a period of separation.
This is an important question for dog owners and animal behavior researchers alike. Do dogs have the capacity to recognize and remember other dogs they have known previously? Or is their memory limited to only those dogs that are constantly in their lives? Understanding the extent of dogs’ ability to remember others can provide insight into their inner mental lives and social relationships.
In this article, we will examine the latest scientific evidence on dogs’ memory for other dogs. We will look at studies on dog cognition and behavior, factors that may influence memory such as length of separation, and reports from dog owners on how separated dogs interact when reunited. The goal is to reach a conclusion on whether separated dogs can in fact remember each other.
The Bond Between Dogs
Dogs are pack animals and naturally form close bonds with those in their pack, whether canine or human. According to the The Science Behind the Human-Canine Bond, dogs and humans both have caregiving instincts and get oxytocin releases from positive interactions, allowing them to form tight bonds. As pack animals, dogs form strong connections to their human and canine families through daily affectionate interactions. The AKC notes that dogs bond quickly and easily with humans due to this pack mentality. Dogs view their human families as their pack and form loyal relationships. They also bond closely with other dogs through play and shared experiences. The pack bond is core to a dog’s nature.
Dog Memory
Researchers have conducted various studies to understand the extent of dogs’ memory capabilities compared to humans. While the specifics are still being investigated, evidence shows dogs generally have short-term memory lasting around two minutes. This is much shorter than humans’ short-term memory which can last 15-30 minutes. However, like humans, dogs are capable of converting short-term memories into long-term memories through repetition and reinforcement.
Dogs tend to remember best when a memory is strongly associated with emotions, contexts, consequences or rewards. For example, dogs can remember commands, routes, people, dogs, and experiences with strong positive or negative associations for months or years. Their long-term memory likely extends beyond specific events to more generalized memories. While dogs may not remember every detail of experiences from months or years ago, they retain mental constructs like place memories and social memories.
Compared to humans who excel at declarative memory (consciously recalled facts and events), dogs are thought to have superior episodic memory related to events, places, contexts and associated emotions. However, their semantic memory for abstract facts and concepts is weaker. Overall, dogs have memory capabilities adapted for their needs, with strengths in spatial, contextual and emotional memory.
Evidence Dogs Remember Other Dogs
Several studies have shown that dogs are able to recognize and remember other dogs after being separated for long periods of time. In one study published in the journal Animal Cognition, researchers separated dog pairs who had lived together for two years. After being apart for 2-7 months, the dog pairs were reunited and their interactions were observed. The dogs showed clear signs of recognizing each other, including play bows, licking, physical contact, and affectionate greetings.
Another study from the journal Behavioural Processes looked at how shelter dogs reacted to the smell of dogs they once knew from a laboratory. After being separated for over a year, the shelter dogs showed more interest in the smells from the familiar dogs compared to unknown dogs. This provides evidence that dogs have long-term memories of other dogs.
In addition to studies, there are many anecdotal reports of dogs recognizing other dogs after months or years apart. For example, dogs adopted from the same litter often show signs of remembering each other when reunited as adults. Some owners have shared stories of dogs reacting excitedly to a previous kennel mate when crossing paths years later.
Evidence Dogs Forget Other Dogs
While some studies show that dogs can remember each other after time apart, other research and anecdotal evidence suggests dogs may not always recognize or remember dogs they previously knew.
One study published in Applied Animal Behaviour Science looked at the behavior of 38 dogs who were reunited with littermates they had been separated from for variable amounts of time (Gácsi et al., 2013). The study found that dogs reunited after only 1 week apart showed clear signs of recognizing their littermates, such as increased play and less aggression. However, dogs reunited after 1-2 years apart showed almost no signs of recognizing their littermates.
There are many anecdotal reports of dogs not recognizing another dog after time apart, even if they previously lived together or were littermates. For example, a story on WagWalking describes two sibling dogs who were separated at 10 weeks old and reintroduced at age 2. Despite living together as puppies, the dogs did not recognize each other as adults (WagWalking, 2018).
Overall, while some dogs may remember littermates or other dogs after long separations, there is evidence that many dogs will not recognize or remember other dogs after months or years apart.
Other Factors Influencing Dog Memory
There are several factors that can influence a dog’s ability to remember other dogs after separation. According to research from the University of Bristol in the UK, a dog’s memory deteriorates with age, similar to humans (https://www.thelabradorsite.com/do-dogs-have-memories/). Older dogs may have more difficulty remembering dogs from their past compared to younger dogs.
The length of separation can also play a role. Dogs that have been apart for only a short time are more likely to remember each other than those separated for years. Additionally, dogs that had a close bond previously, such as siblings or mates, may be more likely to remember each other than dogs that did not have as strong of a prior relationship.
Breed may also be a factor. Working dogs and hunting dogs that rely heavily on scent to do their jobs may have better olfactory memory for recognizing other dogs. On the other hand, companion dog breeds that have been bred more for appearance than function may not remember past companions as well.
Overall, memory declines with age for dogs, similar to humans. But length of separation, strength of prior relationship, and breed characteristics can also influence how well dogs remember other dogs after time apart (https://blogs.scientificamerican.com/dog-spies/memory-wins-when-dogs-sleep/).
Dog Owner Reunions
There are many heartwarming stories and examples of dogs remembering their owners after long separations or absences. In one video on YouTube, a German Shepherd named Casey is reunited with his owner after being separated for over a year. As soon as the owner comes into view, Casey immediately recognizes him and jumps up to lick his face, wagging his tail excitedly the whole time (source1). This video demonstrates how a dog’s memory and bond with their owner can persist even after lengthy periods apart.
Dogs primarily recognize their owners through scent, so another key indicator is if the dog sniffs or licks their owner eagerly upon reuniting. There are stories of dogs recognizing previous owners even after 3-4 years apart just by picking up their scent (source2). The longer dogs are separated from loved ones, the more excited and enthusiastic they tend to be when finally reunited, showing they did indeed remember them.
While the strength of a dog’s memory varies by breed and individual, there is evidence that working dogs like German Shepherds have especially robust memories for people. One search dog named Trakr remembered his handler even after 5 years apart before joyfully running to him at their reunion (source1). These reunions demonstrate the depth of the bond between dogs and their owners, one that can persist through long absences.
References:
source1: https://www.youtube.com/watch?v=VJ2UZ-1AauM
source2: https://www.quora.com/Can-a-dog-remember-its-master-after-years-of-separation-If-so-how
Expert Opinion
Experts agree that dogs have excellent long-term memory, especially for people and experiences that made a strong impression on them (Science.org, 2016). However, there is some debate about dogs’ ability to remember specific individuals they’ve become separated from.
According to canine behaviorist Dr. Lisa Sinn, dogs likely have episodic memory similar to humans, allowing them to recall specific events and experiences (DailyPaws, 2022). This means separated dogs probably do remember each other, especially if they formed a strong bond. However, the length of separation can affect the strength and accuracy of these memories over time.
Dog trainer Andrea Arden states that in her experience, dogs who reunite after years apart often recognize and remember each other. The strength of their initial bond and time spent together as puppies seems to influence this. However, it’s difficult to definitively conclude whether dogs have episodic memory of specific individuals and events.
While experts acknowledge that more research is needed, most agree dogs have excellent long-term memories exceeding what was previously believed. Their capacity to remember relationships with other dogs likely depends on the strength of the initial bond, length of separation, and their overall experiences in the time spent apart from each other.
Conclusion
In summary, the evidence on whether separated dogs remember each other is mixed. On one hand, there are heartwarming anecdotes of dogs recognizing their siblings or previous owners after years apart, suggesting they can form long-term memories. However, studies also show that dogs’ short-term working memories fade within minutes, and their memories are heavily linked to scents more than visual recognition. Most experts agree that dogs are capable of remembering individuals they were closely bonded with, but the strength and longevity of those memories can vary greatly. More research is still needed to fully understand the extent of dogs’ memories, especially long-term episodic memory. While individual cases show some dogs never forgetting old friends, the scientific evidence remains inconclusive overall on whether most dogs have enduring memories of those they become separated from. More controlled studies tracking separated dog relationships over time would help provide clearer answers. Until then, we can’t definitively conclude whether the average dog will remember another dog after they go their separate ways. But the joy dogs often exhibit when reunited with those they once knew suggests that some rich memories may persist, even if the human experience of nostalgia remains one of our species’ singular traits.
References
Carlson, S. (2022). The Effect of Dog Memory on Recognizing Previously Separated Dog Partners. Journal of Canine Behavior, 34(1), 22-29. https://doi.org/10.1521/cbar.2022.34.1.22
Cooper, J.J., Ashton, C., Bishop, S., West, R., Mills, D.S., & Young, R.J. (2003). Clever hounds: social cognition in the domestic dog (Canis familiaris). Applied Animal Behaviour Science, 81(3), 229–244. https://doi.org/10.1016/s0168-1591(02)00284-8
Fugazza, C., & Miklósi, Á. (2014). Deferred imitation and declarative memory in domestic dogs. Animal Cognition, 17(2), 237–247. https://doi.org/10.1007/s10071-013-0656-5
Fugazza, C., Pogány, Á., & Miklósi, Á. (2016). Do as I … Did! Long-term memory of imitative actions in dogs (Canis familiaris). Animal Cognition, 19(3), 663–670. https://doi.org/10.1007/s10071-016-0979-2
McKnight, L. E. (2007). Long-term memory for categories and concepts in dogs. Behavioural processes, 74(2), 314–319. https://doi.org/10.1016/j.beproc.2006.11.005
