Daisy, the Boxer, has always been a relatively shy animal. Outdoors, she will bark at strangers, but she will never approach closer than 20 feet or so.
Kitty, the Boston Terrier, is aggressive, having been raised with two teenage boys. Outdoors she will head like a heat-guided missile toward any stranger. We keep her under watchful control.
Kitty has always hated the doorbell. She knows only strangers ring doorbells. That means she goes into attack mode. We restrain her when the doorbell rings.
But Daisy, as she approaches her second birthday, welcomes anyone we invite into our home. I suppose she instinctively feels that if a person is permitted into the house the person is at least affiliated with her pack. In fact, Daisy has several people she likes and wants to greet.
In the past two weeks, Daisy has begun to dominate Kitty whenever anyone Daisy likes comes into the house. She likes our neighbors. And she developed a relationship with a man we hired to clean out a fence row.
Daisy now jumps astraddle Kitty and pins her to the floor if Kitty barks or acts aggressive toward one of Daisy's "friends." It is a rambunctious sight, for Kitty otherwise is "pack leader," and she does not easily give way. Yesterday a dominance fight (no biting, no bloodshed, no injuries, simply an attempt by Daisy to pin Kitty to the floor) lasted so long that I ended up pinning both dogs to the wall with my power-chair.
In all other matters -- food, water, first access through doors -- Daisy defers to Kitty, and that makes these dominance contests an extended affair. In most dog packs, it takes but a growl or a nip from the leader to put a miscreant in place. With this, a person not aware of the dynamic might feel as if there will be blood.
The shifting dynamic, what with Kitty in her twelfth year and feeling her age, is no easy thing for the sentimental to observe.