Compatibility is not decided in five minutes
A first greeting is only one data point. Dogs may behave differently on leash, behind a fence, in a home or around valued resources. The aim of an introduction is not to force play. It is to create enough space for both dogs to notice one another without losing the ability to disengage.
If either dog has a known bite history or serious dog-directed aggression, get professional help before attempting an introduction.
Use movement and distance
When appropriate, two handlers can begin with a parallel walk at a comfortable distance. Keep leashes loose enough for natural movement and reward check-ins with the handler. Gradually reduce distance only when both dogs remain able to sniff, look away and move normally. Face-to-face leash pressure can make greetings more difficult, so avoid holding dogs nose-to-nose.
Make the home boring at first
Before bringing the new dog inside, pick up food bowls, chews, favorite toys and other obvious resources. Use gates or separate rooms so the dogs can decompress after the introduction. Short periods together are easier to evaluate than several continuous hours.
Watch for prolonged freezing, hard staring, repeated body blocking, cornering or one dog relentlessly pursuing the other. Interrupt early with distance rather than waiting for a conflict.
Protect rest
Dogs living together do not need to share beds, crates or feeding areas. Each dog should have a place where the other dog cannot bother them. Rest is especially important for a newly rescued dog that may already be carrying a high stress load.
Neutral coexistence is a good outcome
Not every pair will become playmates. Calm coexistence can be an excellent relationship. Measure success by whether both dogs can eat, sleep, move through the home and seek human attention without chronic tension. Friendship, if it develops, can take time.
Reference framework
This guide is informed by widely used rescue-management principles and general educational material from veterinary and animal-welfare organizations such as the AVMA, ASPCA and relevant emergency-management agencies. No external links are embedded in this publication.