The best way based on new behavioral analysis, is that dogs use their nose/scents for almost all of their interactions. Eyesight is a very tiny part of what they use. So the theory is, the night before they meet, the new incoming dog's few toys are randomly droped and not acnowledge at all by the homeowner. Just leave there around 15 mins. Then put those toys in the garage for 20 minutes while you guys chill. Then put your dog for a second somewhere she can't see, you being in the toys and drop again randomly. Get the new dogs scent in the house. Remove them after 15 minutes are you are done for the first part.

Day of the meet and greet, do the same thing with the new dogs toys, but your dog can't see you do it. Then let her out of the room or wherever and do the scent thing. Don't acknowledge it at all, just sit down or walk around doing something else while she is sniffing. Put toys away, then do one more time.

Then you are ready to meet on neutral ground. Scientists actually found they can form a bond between eachother just from scent. Then at the meet and greet walk to same direction so dogs NEVER make eye contact for at least 5 minutes (as best you can). Your dog will smell her and now its that buddy. Eventually catch up but neither of you let them turn around and confront. BOdy language of the dogs will trigger agression. So will holding tight leashes even ore. Just let them slowly take 15 minutes to do their things, maybe snarl a little bit, do their dog talking, and hopefully they will understand eachother....I mean they already met two days ago with the scent and were wonding all night about who that was. Let the new dog into your house first and put her in a room, so the resident dog can't see her. She will smell the new dog. Wait 15 to 20, then take the resident dog somewhere where she doesn't see the new dog come out. Let the new dog investigate. Maybe do that twice. Then just don't pay attention or talk, or look at them. They will figure eachother out in most cases. Sorry I wrote so much, but it works wonders especially after you give them more time after the 2 day scent and then non confrontational meet. Most important besides scent is even the being able to lay eyes on eachother at the scent rounds, and the first inital walk of the meet and greet. the first night (new dog wouldnt be there anyways), and the next morning after the 2 short rounds of smell introduction...then off to the netral zone! Best to just let go of leash and don't say anything as long as you can and kind of look out of the corner of... (more)

I hope someone reads these posts, it is also how you introduct a second dog into your home in a 2 to 3 day process. NO eye contact, just scent for the first few days. They should form some sort of bond after 15 minutes of their first meeting. Of course no dogs are perfect but that is your best chance. Neutral dog meeting will only work with non aggressive and mellow dogs, and its especially bad when the collars are tightening and making more tension. Enjoy I hope you try it! It might change your dog forever if you do it two or three times with other nice dogs. It's letting them get initial eyesight that will set off the defensive behavior. My dog by heself reabilitated a rescue greyhound somehow, my lab reads their needs so well...pretty weird. I am going to do the scent thing... (more)

the night before and in the morning after your dogs each. No high pitch talking. Just stroll around like nothing is going on. They will smell all the scents, look at you (don't look back, read a magazine like its all cool). After the first nights scent introduction then caress your dog how they like. Same thing after the two intervals in the morning, then off to the neutral zone. Try your hardest to give them 15 minutes first walking at least 40 to fifty feet apart not facing eachother. Then last person slowly catches up, Humans talk and dont look at them. They will figure it out most likely in around 15 minutes. Remember no leash or at least full slack, or that will set off tension. Also the first night after the first two 20 minute scent introductions, just take the new dogs toys out of the... (more)

Just be relaxed, don't talk, have the plan, and let the dogs be dogs. Gives a much better reliability that they might like eachother, because technically they really did meet the night before. Even just hiding the new dogs few toys around, the resident dog will now. Just don't baby the resident dog. Just chill and let her investigate for 15 minutes, then remove them into the garage. Then repeat again one more time the night before. Twice in the morning. They will then know eachother already before ever laying a sight on each other. When you get back to the house, stop in front yard for a few minutes. then slowly move in with some treats, then totally ignore them and most likely after 10 or 15 minutes they will be cool. It's not hard and an intersting experience that has worked 80% of the time... (more)

Although not everything works, the best behavioral science on this is in regards to each other's scents. You have to first introduce scent articles like each other's toys, while one dog is put away and can't see the other. Do this for 15 minutes so the resident dog around and smell. Then let the new dog smell around the residents dog scent. They can never see eachother. Then go way neutral and walk the same direction 20 feet apart. Gradually get closer and walk slower so the resident dog eventually can smell her for a while, then let them meet without holding any colar which creates tension in the dogs. Even better, introduce a few of the incoming dogs toys around the house the night before so she can get a whiff in two 20 minute intervals. Just don't pay attention it, they are getting to... (more)