Pleased to Meet You: Introducing Dogs to Each Other Safely


We love dogs. Dogs, despite our flaws, love us. Dogs, like humans, are a social species, and it is hardwired into them that they belong in a social group. Many breeds of dog have been bred to “pack up” with humans and share our lives, whether it be performing tasks for us, or just being companions. I believe that domesticating dogs was one of the smartest things humans ever did, on the whole.

(We haven’t always made decisions that benefit the dogs during this process, sadly. But that’s grist for another mill.)

Social species like to hang out with their kind, and dogs are no exception. Most pet dogs enjoy the company of other dogs, and this tends to work out well in our dog-saturated culture. We see dogs on our daily walks, at the park, at our friends’ homes, in stores and businesses. It’s definitely a plus when dog owners can be around each other and have our dogs mingle happily.

At some point, if you own a friendly dog, you will likely want him to meet other dogs, whether it be your friends’ dogs, or stranger dogs at daycare or dog parks, or if you plan to bring another dog into your home as a companion for him. You may decide to procure a companion for him based on how you have seen him interact with other dogs in these situations.

Some dogs aren’t super happy around other dogs, to the chagrin of their owners. It can be embarrassing to own a dog that doesn’t like other dogs, or is openly hostile to them. It’s a common complaint that dog trainers deal with, and sometimes, there isn’t a fix for it. If you own a dog or dogs who are happy with each other or their humans, but don’t want to be around strange dogs, that could just be a personality issue that you will have to accept. Outright aggression to other dogs must be treated, but being the owner of a persnickety pooch who isn’t actually aggressive but just introverted is not the end of the world. Give him his space and accept him for who he is.


Dogs are often compared to potato chips and tattoos: once you have one, it’s hard to stop! Many dog owners seek out additional dogs for a number of reasons, and it’s important to know how to introduce them properly. “They will work it out on their own” is not a solid roadmap to success. Some planning and consideration beforehand will be very helpful. Many happy, friendly dogs can and do work things out pretty easily, but don’t make assumptions.

Let’s assume that you have done your homework and know that your pooch is ready for a friend, and you’ve selected a great candidate to come and share your home. If the two dogs have met previously at the shelter or at a park, you might be able to skip some of the steps below if they already occurred at the first meeting. But if that first meeting was strictly on leash, follow all the instructions.

Whether they’ve met, or they’ve never seen each other before now, it helps to be prepared.

NOTE: this article was written for introductions between dogs that are close in size to one another. There are other challenges to consider when you put dogs of differing sizes together, whether temporarily or permanently. See the end of the article for more information.

Preparation matters! There are several ways to go about the first meeting between your existing dog (“Home Dog”) and the New Dog. Make sure both are wearing secure collars that are NOT training collars (nothing that “bites” or closes around the dog’s neck for training or walking purposes). Typically, we are talking about the regular collar your dog wears that holds his tags. A collar with a quick-release buckle is ideal for this.

You want the collars to be securely fastened so that you can only fit a few fingers underneath. Attach leashes securely to these; 6-foot leashes are ideal. Leashes should not be attached to harnesses for this, as you will not have any control of the dog’s head if things don’t go well. DO NOT USE retractable leashes!

You may choose to use 6-foot slip leashes instead of clip-on leashes. Make sure the “stoppers” are snugged down so the leashes cannot come off by themselves.

PREPARATION FOR HOME: make sure both dogs have crates. Crate-trained dogs will handle the introduction process better, so crate train Home Dog before you do the introductions. If the New Dog is already crate trained, that’s excellent. NOTE: dogs must have SEPARATE crates! NEVER crate more than one dog in the same crate (if they love each other and later curl up together in a crate when the door is left open, that is fine, but never lock 2 dogs in one crate, NO MATTER WHAT).

Step 1: Introduce on neutral territory if at all possible.

What is considered neutral territory? Ideally, it would be a place where neither dog lives. Examples are a city park (not in a dog park), or a friend’s yard. Since loose-leash or dragged-leash greetings are best, the dogs will have a better meeting if it is securely fenced so that humans don’t need to hold the leashes (more on this in a bit).

It is rarely a good idea to introduce a new dog within the existing dog’s territory. Don’t just bring the new family member in and set her down in the living room for Home Dog to investigate. Do not hold her in your arms for Home Dog to investigate, either!

Step 2: Introduce with movement.

Walk the dogs, one dog per adult handler, parallel to one another (side by side in the same direction) on 6-foot leashes with enough distance between them that they cannot physically interact. The better leash trained they are, the easier this will be. If you are in a yard, walk this way around the perimeter of the space for a minimum of 5-8 minutes before proceeding to the next step.

Do NOT allow the dogs to physically interact at any time on this pre-walk!

Step 3: Watch for clues in the dogs’ body language.

Clues that portend well are:

  • Curving or bending of bodies
  • Elbows bent, especially with butt in the air (play bow)
  • Tail base level in line with body, slightly below, or slightly above
  • Ears “soft” or back, or ears that change from forward to back
  • Open mouths with wide “grins” (may be panting normally)
  • Normal eye contact that breaks off
  • Excited, playful barks
  • Occasional sniffing of the ground, as if uninterested in other dog

Clues that do NOT portend well are:

  • Stiff bodies
  • Staring
  • Hunching down
  • Not breaking eye contact
  • Closed mouths with pursed lips
  • Piloerection that does not abate during the pre-walk
  • Predatory behavior like stalking
  • Ears far forward that stay that way
  • Base of tail high, especially if tip is vibrating
  • Low, rumbling growling

NOTE: In assessing dog body language, you need to look at the whole picture—not just one or two clues. One or two of these negative clues by themselves, or seen in conjunction with several of the clues in the first list, may not be problematic. For example: one of the dogs has piloerection and a closed mouth, but then gives a few play bows and his tail drops level with his body as his mouth opens. Keep walking, and see what changes. If things tilt toward the positive, you should be OK.

Step 4: Release with calm energy if clues portend well, and pay attention.

If you are in a safely fenced area, after enough* parallel walking, drop the leashes of both dogs simultaneously, without fanfare, and keep walking. (Do not unclip the leashes at this point! The dogs will drag them as they move and interact. This is what we want. They may get tangled a bit, but it rarely inhibits play; if things go south, it’s a lot easier–and safer–to grab a leash than a collar.)

NOTE: if you are seeing 3 or more clues from the second list and few or none from the first list from either or both dogsdo not release the dogs at this time. Continue walking parallel in the space for 5 more minutes, and see if the dogs “soften” at all. If they don’t, abandon the meet for now. It’s not safe.

Step 5: Movement reduces stress.

If the humans move calmly and with confidence, the dogs will feed off this “energy” and read cues from you—and they will move, too. Watch the dogs as you move. Stay alert but do not hover. If you saw good body language* during your parallel stroll, you will likely see it here, as well. The best scenario is that Sadie and Max will approach each other with “bendy,” curved bodies in a semi-circular fashion, smell, circle a bit, then play bow and take off with a game of chase. This game should alternate between chase and wrestle, with both dogs taking turns at being chaser/chasee, dog-on-top/dog-on-bottom. Ideally, there will be minimal slamming or knocking over, and both dogs should look as if they are enjoying the interaction.

Step 5 (b): Movement means humans, too! 

The humans should continue walking around the perimeter of the space for a bit, then can proceed to more casual milling about. It is a good idea to continue moving, regardless of the path you take. If the people move, the dogs will, too, and that dissipates stress.

Step 6: Split them up

Once the dogs are loose and happy, as they begin to tire, pick up the leashes and resume a parallel stroll one more time around the perimeter of the space. They should not interact during this.

Step 7: Hit the road

Leave the space and head home. If the dogs will ride together in the car, they should be confined apart from each other if possible. Once you are home, walk around your yard just as you did in Step 2 above, then walk both leashed dogs into the house, new dog first.

Step 8: Exploration for New Dog

Crate the Home Dog and remove his leash. Toss a blanket or towel over his crate to give some privacy if the crate is not in a room that can be shut off. Allow the New Dog to roam about the home a bit, dragging her leash (watch her closely if her housetraining is in question; I assume all new dogs are not fully housetrained until I know better). Pick up the end of the leash and follow her (leave the crated dog alone).

Step 9: Exploration, continued

Take her out to the yard if there is one. Keep the leash on; she can drag it if it is fenced. Let her smell and explore a bit, and eliminate in an area you prefer.

Step 10: Proceed with structure and awareness

Bring her inside and crate her. Keep both dogs crated for a few hours minimum so they can chill independently. This will help set the stage for New Dog to start understanding boundaries, as well as provide quiet time.

If the meeting went well, it is probably safe to allow them to interact inside the home and outside in a fenced yard without leashes in the coming days, but I suggest having them drag leashes at the beginning of the interactions until you have seen them enjoying each other without incident in all areas for a few days. Unclip the leashes when you are satisfied that all is well.

Keep your excited baby talk, treats, and toys at a minimum for now. Be calm and controlled. Feed them in separate rooms, or in their crates, or in the same room on opposite sides with you hanging out in between and not allowing interaction during the meal.

Crate them when you are not around to supervise so they do not have unfettered access to each other. No matter how attached they may already be, leaving them alone together at this stage is not recommended. (This is especially true if there is a vast size difference between them.)

As things progress, allow them more time together. If Home Dog already had free run of the house, that can resume. Keep New Dog crated when unsupervised until she earns the privilege. Enjoy!

Potential problems in the coming days/weeks

Dogs can be possessive over toys, food, sleeping spots, and even human attention. This may not have shown up in the shelter or at the first meeting, because you were on neutral territory with those items out of view. Keep toys, bones, and feeding spots separate for a few weeks to make sure there aren’t going to be squabbles over them. Contact a trainer if you feel like problems are brewing over these resources. Look for body language cues (above) to help clue you in.

Structure matters when you bring a dog into a new environment. 

Teach the new dog the existing rules and make sure both dogs follow them. This will help ease the transition and cement your status as a benevolent leader. Stay attentive.


Follow steps 1-8 above for dogs who have never met and will be spending some time together in one or the others’ homes, but will not be living together per se.

Once they are inside and playing nicely, continue to let them drag leashes for a while just so you can keep a bit of order. If the visit is longer (overnight), it’s helpful to use crates and do a bit more monitoring. The more often the Friend’s Dog comes to visit, the easier it will become.

Remember, though, the potential for resource guarding or territorial aggression exists with dogs who won’t live together 24/7 but will visit regularly. It’s best to keep toys and other valuables to a minimum when having a sleepover.


If you’ve made it this far, you may have noticed that helping dogs have safe introductions ideally takes a bit of time and prep, and that these introductions are never done on tight leashes in small spaces with little or no movement.

Unfortunately, on tight leashes in small spaces with little or no movement is how a vast majority of dog meetings go in the community. A woman is walking her dog, and sees a man walking his dog. Thinking that they should socialize, both humans approach each other with their leashed dogs, who are typically leaping and jumping to get to the other dog, or barking frantically. When they get close enough, they come together head-to-head, on tightly held leashes, with no room to move and sniff and meet properly.

Believe it or not, this is disrespectful to the dogs and can become dangerous quickly.

“Sure,” you are saying, “but I see it happen all the time, and I’ve even done it with my dogs, and everything works out fine! Dogs need socialization, and you don’t like dog parks as a rule, and we can’t just let them off leash, so what can we do? I think you are being too unreasonable.”

I get it. I really do. Some dogs can meet in this way and not engage negatively. But just because fights don’t break out all the time when people do this, it doesn’t mean it’s something you should do. Dogs are fine until the day they aren’t. It’s your job to keep your dog safe and healthy, and “socialization” done this way isn’t really socialization. What it is doing is putting your dog in a stressful situation because you think it’s beneficial to him, not because it really is.

Look at it this way. Humans are a social species, just like dogs. When you meet a stranger who would become a friend, how would you say you socialize? You exchange pleasantries, you walk into a bar or restaurant, maybe, you sit 3-4 feet apart, and you chat. You observe each other’s body language and social cues from several feet apart. After a period of time, you part ways, maybe with a handshake (possibly with a hug, but this isn’t standard protocol for having just met someone; even “hugger types” will wait until the second or third meeting generally). This is human socializing. Sure, exceptions exist, and alcohol consumption can change this picture drastically, but you get the idea.

Note the lack of “in your face” tactics. Each party keeps a culturally appropriate distance until they, through several visits, have established trust with one another. Why? Because it would be rude to be “in your face.” When you first are introduced to another human, it’s weird to be too close too fast.

If two people who don’t know each other were to approach on the street and get right in each other’s faces, we wouldn’t consider that “socializing,” would we? It would be seriously creepy, at the very least.

Dogs aren’t primates, but we can apply the same rules to their meetings. Dogs with good social cues never rush into other dog’s faces. If bodily contact is initiated early, which it sometimes is when dogs are introduced off-leash, when it is done between good communicators, it’s not face-to-face right away. There is usually contact on a shoulder or hip first, and most dogs start with some running—movement—before getting right to “mouth play.”

If you took a poll from a multitude of professional dog trainers with experience, nee experts in the field, and asked them if allowing dogs to meet nose-to-nose on tight leashes is a good idea because it doesn’t erupt in violence every time, they would tell you that it’s a fight waiting to happen. Add retractable leashes and dogs without impulse control, and the chances for problems rise substantially. Listen to the experts: keep your dog safe.

That said, is there a way to safely introduce your dog to other leashed dogs while you are out and about? The answer is: it depends. And it’s a difficult one to quantify because there are a lot of uncontrollable variables, both in regard to your dog and the dogs you will encounter. What I will say is this: you will not be denying your dog something valuable if you do not allow him to engage face-to-face with other leashed dogs. There are better and safer ways to socialize.


What if the dogs you are planning to introduce are vastly different in size (say, a Chihuahua and a Boxer)? All of the same considerations above apply, but other aspects of each dog’s temperament and personality will come into play here, as well as breed, and you should take extra precautions.

For situations in which the dogs will only be interacting one time and/or for a short period, simply do not introduce. Just keep them separated and be on your way.

For “out and about” on a walk, the same applies: no face-to-face greetings, and no holding the small dog for the larger dog to “sniff.”

For the friend situation where the dogs will be spending some time together, it’s best to understand as much as possible about how the toy dog feels about larger dogs in general, and how the larger dog sees toy dogs. Some toys LOVE big dogs and are happy in their company, and if the pairing is right, they can coexist quite happily eventually. Many larger dogs LOVE small dogs and really only want to play (not eat) them, but they don’t understand their own size or strength and could hurt the smaller dog without meaning to. The better trained the larger dog, the easier it will be because you can step in and call him off if things get too hairy. If the toy dog is scared of larger dogs, do multiple parallel walks on different days before releasing them, and make sure the larger dog is pretty tired already. Keep leashes dragging the entire time. If the smaller dog gets overly scared, grab up leashes and resume the parallel walk and end with that.

Toy dogs can be very territorial and defensive because of their small size and vulnerability. If the exisiting dog is a toy breed or breed mix (under 15 lbs) and the new dog is a large breed or a very predatory breed or individual, you must protect the smaller dog from the get-go. Many larger dogs see small dogs as prey, which can result in serious injury or death to the smaller dog. You would likely notice predatory signals during the parallel walk (see section 3 above) that should tip you off. If you have doubts, do not allow them to mingle.

Many people try to hold the smaller dog to allow introductions, which is actually not recommended, as it puts that dog at a disadvantage and can increase the predatory tendencies of the larger dog. It also makes the smaller dog more defensive and he may act out, which may trigger the larger dog to attack. Other actions that can trigger an attack are screaming, squealing, darting away, and even submissive rolling over.

If the larger dog routinely chases cats and squirrels, he likely has more predatory tendencies. If he ever catches them and kills them, he definitely does, and you need to be very, very careful–unless he is VERY responsive to commands, he may not ever be safe around very tiny dogs.

If the larger dog is an unknown entity, assume he has predatory tendencies until you can determine otherwise! Do not put toy dogs at risk just because you feelk like they should be OK together. Accidents can happen in an instant, but they are preventable. Prevent them.

A predatory large dog can break through (or leap over) baby gates to get to a smaller dog. Use sturdy crates whenever the dogs are unsupervised; in separate rooms with a closable door is best if you are worried.

Never leave 2 dogs alone together until you are very sure that they have accepted each other and enjoy each other’s company. Too many people who have a large dog at home often want a small dog to be a lap dog, and they do not realize the dangers. They don’t take precautions, leave the dogs alone together, and then they come home to a terrible scene. Dogs are predators and this is NOT their fault. You are responsible for all the dogs in your care.

What if the larger dog is a pushover, but the smaller guy is very predatory or “in your face”? The larger dog is not in danger, but if he is bothered enough or attacked by the smaller dog, he may retaliate, and it doesn’t matter who started it–the small dog will likely lose. Don’t laugh and allow your small dog to pester a larger dog! It’s not fair and it’s not safe.

Small dogs need training, too, so if you have a toy who is a jerk, fix that before you subject him to other dogs or bring home a larger dog.