Dogs do have feelings for other dogs. They form genuine emotional bonds with canine companions, experience distress when separated from them, and show measurable signs of grief when a bonded partner dies. This isn’t just projection from loving owners. Brain imaging, hormone studies, and large-scale behavioral research all point to the same conclusion: dogs experience something real and meaningful in their relationships with other dogs.
What Happens in a Dog’s Brain
The strongest evidence comes from brain scans. In a study at Emory University, researchers trained 12 dogs to lie still and awake inside an fMRI machine, then presented them with different scents: familiar humans, unfamiliar humans, familiar dogs, unfamiliar dogs, and their own scent. The researchers focused on the caudate nucleus, a brain region associated with positive expectations and reward. The caudate didn’t just light up for any scent. It responded selectively, activating most strongly for the familiar human and showing distinct patterns for familiar versus unfamiliar dogs. This means dogs aren’t just detecting who’s nearby. They’re having a positive emotional response tied to specific individuals.
The olfactory processing center, by contrast, responded about equally to all scents. So the discrimination isn’t happening at the level of “I can smell something.” It’s happening at the level of “I recognize this individual, and they mean something to me.”
Hormones Behind the Bond
Oxytocin, the same hormone that strengthens bonds between human parents and their children, plays a role in canine social relationships too. When dogs cuddle with someone they know well, their oxytocin levels can spike dramatically. In one study, dogs that responded to physical affection from a familiar person showed oxytocin increases averaging 55 to 73 percent, with some individuals more than doubling their baseline levels.
While most oxytocin research in dogs has focused on the human-dog relationship, the underlying biology is the same. Dogs produce and respond to oxytocin during positive social contact with other dogs as well. This hormonal system rewards closeness and reinforces the desire to seek out specific companions.
How Bonded Dogs Behave Together
If you’ve watched two dogs who genuinely like each other, you’ve probably noticed the signs without needing a study to confirm them. Bonded dogs synchronize their behavior. They settle down for naps in the same spot, often curled against each other. They groom one another, licking ears and faces in a way they don’t do with unfamiliar dogs. They play together in patterns that become more coordinated over time, with shared signals and rituals unique to their pairing.
The flip side is just as telling. When bonded dogs are separated, even temporarily, they often show visible distress: pacing, whining, watching the door, or refusing to engage in activities they normally enjoy. This isn’t generic anxiety about being alone. It’s directed at the absence of a specific individual, which is the hallmark of a genuine social bond.
Dogs Grieve When a Companion Dies
Perhaps the most compelling evidence that dogs have real feelings for other dogs comes from what happens after loss. A large study published in Scientific Reports surveyed owners of dogs whose canine companion had died and found widespread behavioral changes in the surviving dog. Sixty-seven percent of surviving dogs sought more attention from their owners. Fifty-seven percent played less. Forty-six percent became less active overall. Thirty-five percent slept more, and the same percentage showed increased fearfulness. Thirty-two percent ate less, and 30 percent vocalized more.
These aren’t random behavioral shifts. The changes tracked directly with the quality of the relationship between the two dogs. When the pair had a friendly relationship (as opposed to one based on tolerance or conflict), the surviving dog was about 1.3 times more likely to stop playing after the loss. The closer the bond, the stronger the grief response. That pattern mirrors what we see in humans and other social mammals, where the depth of a relationship predicts the intensity of mourning.
How Long Dogs Remember Each Other
Dogs rely heavily on scent to recognize individuals, and their olfactory memory is remarkably durable. Research by Peter Hepper found that dogs can recognize the scent of their mother or offspring after a two-year separation, showing clear preference for that scent over an unfamiliar dog’s. Interestingly, they didn’t show the same recognition for siblings after the same period, suggesting that the strength of the original bond matters for long-term memory, not just genetic relatedness.
Dogs also distinguish individuals by voice. Vocal individuality is widespread across the canine family, and dogs respond differently to the barks and whines of dogs they know versus those they don’t. The full picture of how long dogs can remember a specific companion is still being studied, but the available evidence suggests that strong bonds create lasting memories, particularly through scent.
Stress Responses Tell the Same Story
Cortisol, the primary stress hormone, provides another window into canine emotions. When dogs are isolated from social contact, their cortisol levels rise significantly, a clear physiological stress response. The presence of a companion, whether human or canine, can buffer that stress, keeping cortisol levels from spiking. This social buffering effect is well documented across social species and confirms that companionship isn’t just pleasant for dogs. It’s biologically protective.
This is why shelter dogs housed alone often show more stress-related behaviors than those with a kennel mate, and why the loss of a bonded partner can trigger such profound behavioral changes. The absence of a companion removes a source of genuine emotional regulation.
What This Means for Your Dog
Dogs experience their social world with real emotional depth. They form preferences, build attachments to specific individuals, feel comforted by familiar companions, and suffer when those companions disappear. Their emotional lives aren’t identical to ours. We can’t know whether a dog ruminates on a lost friend or consciously recalls shared experiences the way we do. But the behavioral, hormonal, and neurological evidence all converge on the same point: the feelings are real, they’re measurable, and they matter to your dog.
If your dog has lost a companion and is eating less, sleeping more, or seeming withdrawn, that’s a normal grief response. It typically resolves over weeks to months, but maintaining routines, offering extra engagement, and being patient with changes in behavior can help. And if you’re considering whether your dog would benefit from a canine companion, the science suggests that for most social dogs, the answer is yes. The bond they form with another dog is one of the most emotionally significant relationships in their lives.