I've noticed with Aaliyah away at shows (the adults stay at home with my brother), when we've been gone for more than 1 - 2 days, there always seems to be a re-introduction that needs to happen. Most of the time we arrive home at night. I've always been a little cautious of just letting them off lead in the house or yard because Ruby tends to growl at Aaliyah when she first comes home - like she doesn't remember her or is mad at her because Ruby thinks she missed out on some fun that Liyah had.
So the re-introductions happen outdoors, in the lighted driveway on leash. I usually try to do 1/1 with Liyah & Ruby and then 1/1 with Liyah & Brando, then all 3 together.
When Liyah was gone a month for the National, I had to do a full on re-introduction (it was like Ruby had forgotten all about Liyah and didn't remember her at all) - separate walks down the road (Liyah & Brando, Liyah & Ruby), group walks down the road.
It is nothing that is a problem with as I've done it so many times now and it works out fine. But I was wondering what others with more than 2 have experienced - when you take one out of the pack for a period of time. And what are some of your re-introduction techniques.