A New Dog Changes Everything!


Daisy the dog has come to stay with us for a while!  Daisy is family, so we already knew her.  She and my dog Albert have visited each other’s homes several times, and played together well.  At both homes, they have successfully worked through small problems like one wanting to play when the other didn’t.  We were optimistic about the experience of having her here for an extended period.

Daisy and Al doing a little mat training.

Change = Stress for Everyone

If you have ever read my blog or visited my YouTube channel, you may know that stress is a favorite topic.  When a dog moves into a home, everyone experiences changes they don’t have much control over, resulting in some level of stress. This includes resident dogs and the new dog.  (It also includes other pets and the humans in the home, but we’ll talk about the dogs in this post.)

A resident dog has to give up some of the space and routines he’s accustomed to and suddenly cope with another thinking, feeling personality moving around his home.  Familiar stimuli for the new dog are only what he or she brought along.  I am in the habit of recommending that when people bring new dogs home, they should not count on previously established behaviors in their resident dogs.  I counsel foster parents to put on a treat bag and focus on teaching the new dog what behaviors they want to see more of and reinforcing the same in their resident dogs. 

A New Dog Changes the Environment

Think about it this way:  Your resident dog has been performing behaviors within a particular home environment which looks pretty much the same every day.  Without much warning, the presence of a new dog has changed that environment.  To your dog, this means he hasn’t performed those behaviors at all.  Behaviors are associated with the environment they occur in, the stimuli that signal opportunities, and the reinforcers that develop the behaviors.  To a dog, performing a “sit” on cue in the presence of a new dog is a completely different behavior from doing so when that dog isn’t there. 


Any of my students will recognize this information.  It’s the basis of the behavior principle of “generalization”, the reason we switch hands when training a nose-to-hand target, and why we “take behaviors on the road”.  We set things up so dogs can perform behaviors well in different rooms, outdoors, and later in public places after training them in a quiet, low-distraction area.  Controlling the distraction level while observing a dog’s behavioral responses helps us introduce distractions at a level the dog can handle.  It’s important to control the presence of the new dog to allow a resident dog some room to generalize behaviors.  

Al’s Previous Environment

My dog, Albert, learned to perform cued behaviors in the presence of three cats and a variety of humans in our home.  He has not performed many of these behaviors with other dogs in our home. We mostly see other dogs at our guest house next door, where we also entertain and carry out dog training business.  Our other house makes a nice place for Daisy to have some alone time while Al enjoys alone time at home.  But we all sleep, eat, and spend most of our time together in our home. 

Right away, we began giving treats for basic behaviors we want to see more of. These include sitting, lying down, sitting at doors and gates before exiting or entering, resting on mats, waiting for food bowls to be set down, crating, walking with us, and more.  The dogs immediately began having good times playing together and they rested pretty well. Nonetheless, I saw increased tension here and there during their play sessions in the first few days.

Al and Daisy trying out lying on a bed together; a little unsure.

Daisy’s Previous Environment

Like Al, Daisy was also trained at home with only humans around, mostly just her owner.  She tends to bark in an alarmed manner when people enter her home, keeping up that barking until she feels more comfortable.  This barking occurs here, even when those entering our house are people she knows and loves, indicating that approaching the door, opening and closing the door, and other sounds and visual stimuli associated with people entering are the initial triggers.  Once the person comes inside, the stress/anxiety induced barking continues for a bit, even when she recognizes the person and offers friendly gestures.  She needs some practice at calming herself after getting excited. She also needs some classical conditioning work around front door behavior.

The visual stimulus of someone she doesn’t recognize also seems to be a trigger, as she backs away from strangers while barking.  Other than over-reacting to people entering the home, Daisy appears to be about the most easy-going dog ever.  It only took her a few days to start lying on her back on the couch with legs pointing at the ceiling, and 6 days to stretch out on the floor, completely relaxed on her side.

Al and Daisy relaxing between play sessions.

Effects of The Matching Law

Changes observed in Albert’s behavior include explosive barking at Jane, the parrot, when she plays rambunctiously or walks on the floor of her cage.  We have been working on modification of this behavior for a long time.  We developed a system in which Al watches the parrot, maybe whines a little, then either comes to check in with a human or is called away.  When Daisy arrived, the behavior reverted to the explosive barking. 

This is a great example of The Matching Law, which describes once-reinforced behaviors becoming part of the repertoire, never to go away.  Even when modified, the old behavior is likely to show up under certain conditions.  Al’s explosive barking at the parrot originally showed up under the stress of his moving in, which was high – the change was sudden, at the age of 5 months, and he was not well-prepared for his unplanned move.  It makes sense that the behavior would show up again under the stressful condition of another dog moving in with him.

Effects of Trigger Stacking

Another change in Al’s behavior was barking at anyone who walked down the public sidewalk across our front yard.  Though he showed limited concern about these stimuli as a puppy, we were very successful in teaching Al that people, dogs, and even horses walking by were fun to look at but nothing to become aroused about.  He routinely watched them through the window, curious but calm and quiet.  When Daisy came, he started barking at these passersby.  It was not explosive barking as with the parrot, but alert barking.  He does not show high concern but simply alerts to the fact that something is amiss.  He is the one who starts the cacophony, and then Daisy joins in.  This is a behavior most simply described by trigger-stacking.

What is Trigger Stacking?

Trigger stacking is something many pet-owners don’t recognize quickly enough, even though it affects humans as well as dogs.  It means just what it says:  Each individual “trigger” or “stimulus” has an effect on a dog’s behavior.  The effects of two triggers occurring at the same time are additive.  For example, let’s imagine that one trigger has an effect of “1”. Another trigger with an effect of “1” happens at the same time.  The effect on the dog is “2”, or twice as much effect on his stress level, producing whatever that dog’s characteristic behavior is in that situation. 

All you ever wanted to know about trigger-stacking and then some!

Humans cannot control the whole world, so in fact, dogs are almost always feeling the effects of multiple triggers.  Most people can relate because humans are also under constant impact of triggers, though usually different stimuli than dogs respond to.  Humans respond to traffic, problems at work, and concerns about home repairs.  Dogs respond to events they aren’t prepared for, people doing things to them that they weren’t expecting, the presence of animals they’ve never seen before, and more. 

Triggers come in many forms.  External triggers can be anything a dog can detect, including sounds, smells, visual stimuli, pressure changes resulting from weather events, feelings when something touches them or even when a stream of air blows their fur or whiskers, and tastes.  Internal triggers include how dogs feel, both physically and emotionally.  These are things like hunger, their state of sleepiness or fatigue, feeling ill in some way, itching due to allergies or other conditions, pain of any kind, and psychological feelings of threat or playfulness.

More Triggers Than You Realize

Triggers change at the drop of a hat and they are very difficult to track, so we try our best to make every event in a dog’s life as positive as we can. Remember, we can’t tell how many other things they are dealing with at the moment.

In Albert’s case, bringing Daisy into our home was not just one trigger, but many.  If we had brought in a stuffed dog, it would have just stood there, never moving – very predictable.  Daisy moves, explores, attempts interactions with Al and with the humans he loves, lies down on furniture, runs, plays, eats, barks, chews on bones when they’re given, and more.  The trigger scenarios are ever-changing for both dogs, as they respond to each other and to the triggering events each one creates.  Humans are constantly responding to both dogs, creating change after change. 

Learning All the Time

Throughout these continuous changes, the dogs are learning.  The humans in my house are well-trained to use their own behavior choices to help the dogs learn desirable responses and behaviors.  But even if no human is involved, the dogs learn from the environment.  The environment changes in response to the dogs’ behavior choices. 

Imagine if Molly picks up a loose bone on the floor and Rover assumes a threatening posture and growls.  If Molly drops the bone and Rover walks away, Molly learns that dropping the bone can make the threat disappear.  Her environment changed as a result of her behavior.

Rover learns that a threat can make him feel better about a situation because Molly let go of “his” bone. His environment changed as a result of his behavior.  He has a chance to pick up the bone or it may be enough that Molly moved away from it.  Either way, Rover feels less threatened when “his” bone is not in Molly’s mouth, and what caused him to feel better was performing a threatening posture and growling at Molly.  This is why I recommend not having loose bones lying around on the floor.

Help Dogs Learn the Right Behaviors

It’s best when dogs feel secure and not threatened, and we don’t want any dog to learn that threatening behaviors are good choices.  Remember the matching law: any behavior that has “worked” once is a forever part of a dog’s repertoire. Humans can easily manage the environment for success by putting high-value items away.  We can also keep a close eye on the dogs’ behavior and encourage them to turn and walk away from conflicts, usually by offering a tasty treat when they do so.  This is training:  being actively involved in what the dogs are learning.  We can begin at the moment another dog is walking in the front door and reap the benefits throughout the next decade(s) of life with dogs in our homes.

Setting Dogs Up for Success

We hear this phrase a lot, but what does it mean?  It means using the environment and our own behavior to get the behaviors we want from dogs.  Both Daisy and Al are good at lying on mats, sitting when asked, and more.  These behaviors allow them to chew bones in the evening while we relax on the couch.  We have them lie on their assigned mats while we eat dinner and watch TV, entertained by healthy chews until we release them when we’re ready.  Both dogs are “set up for success” because:

·        they know what to do (they’ve been trained to lie on their mats until released),

·        they get a wonderful activity while they’re doing it (yummy chews), and

·        the chews reinforce lying on the mat – the behavior gets better with each session.

Setting dogs up for success means paying attention to indications that they feel confident or worried and to behaviors that we know we want to see more of or that we never want to see again.  It means training them in simple behaviors that we can use in everyday life to control the potential chaos in our homes and allow ourselves some relaxation time while the dogs enjoy the same.  Setting them up for success, both in the moment by managing the environment, and over time through training, helps dogs have more opportunities via behavior choices they will make in the future.

Al and Daisy, much more comfortable lying down together.

Training All the Time

We still have plenty of training to do.  Dogs will often take on things as a group that they would not have done alone, and at our house, this has happened with barking at our cats.  We are doing lots of conditioning of relaxation in the presence of cats, teaching alternate behaviors to barking, and helping both dogs make good associations with cats.  Lots of treats for everyone involved!

Benefits of a New Dog

Exercise for both dogs has increased in quality and quantity, as they play chase every day in the pasture.  They are honing their play skills, too!  Daisy is fast and good at chase games, and Albert prefers wrestling on the floor.  They are both developing skills in previously weak areas.  Al is learning quick maneuver techniques to make up for his lack of Daisy’s rocket speed! 

Al and Daisy, wrestling on the kitchen floor. This is really good play – lots of space between dogs, and many play bows offered by both dogs.

Both dogs are building their social skills and manners, too.  They have each learned new routines for meals and grooming.  Both dogs’ recalls have improved.  For the humans, practicing the skills of getting both dogs where they need to go in any given moment is a constant activity.  Dogs in the kitchen, dogs in crates, dogs on mats, dogs outside or in, both going through the gate to the pasture together while using self-control, one dog on the grooming table while the other one lies on the floor – all are routines that Al and Daisy are getting really good at and the humans are improving, too!

One new routine: Al and Daisy, waiting at the gate to be invited to enter the pasture, a super-fun place for playing chase!

Oh hi there!
It’s nice to meet you.

Sign up to receive dog training tips in your inbox monthly and a FREE e-book!

Share this post