Owners often report Interdog aggression in a multidog household. Sometimes the aggression is very serious. A pet owner reported that her 2 y o f Labrador Retriever reacting aggressively toward her two older male dogs, one age 6, one age 9. 

From my experience as a foster care provider, here are suggestions I found effective for introducing a new dog to the household and maintaining the peace.

First, I give the new dog individualized attention for several weeks so that it begins to learn the routines around here and comes to understand the expectations. During this period, I usually institute a "work to earn" program. Oh, my goodness, that sounds so rigid, doesn't it? You'd laugh if you saw how really easy I am with my dogs. You'd be asking me, "When does this leadership program begin?" (LOL) It's subtle, you see.

Well, leadership is not dictatorship; it's a benign thing that dogs seem to comprehend naturally, because they are pack animals and they like being part of the family pack. We can really use that natural inclination to our great advantage. We give the dog lots of attention for the behaviors we wish to reinforce, and we prevent the behaviors we do not wish to reinforce.

Collie

Okay, then, if we're concerned with dog-on-dog aggression at home, we need to separate the dogs a wee distance from one another, such as with secure dog-gate barriers in doorways, or one dog in the outside kennel run or fenced yard while another dog is indoors.

I bring the dogs together but very briefly at first, when they sit-wait for a treat politely as I dole them out one by one to each. We do this little routine twice a day, once in the mid afternoon, again at around 9 p.m.  The exercise helps each dog to exhibit some impulse control.

I have also taught my dogs to wait at landings to stairways, such as the porch steps. At one time while my husband and I were living in a split-level home,  I had four dogs responsive to a single verbal cue or hand signal to "Wait," then all of them  waiting at the top of the stairs while I went to the bottom of the stairs, near the front doorway. And I called each, one by one. This practice was not difficult, and the dogs learned it readily. I just started teaching it to one at a time. I chose this particular exercise because I don't like dogs racing each other down the stairs.

"Wait" is a wonderful, very handy skill to develop in your dogs.  

Next the decision about resting spots, mats or dog beds, should be yours instead of the dogs'. Simply instruct each to "go to your bed," or "go to your mat," and then heavily reward each dog who does so. In fact, that simple behavior lends itself so well to shaping with a clicker and food treats that you may wish to try that. In your situation, I'd continue to give the older two dogs their customary house privileges, since they have been just fine. But I'd separate them from the youngest, the Labrador retriever.

Observe them carefully, however, for any signs of rising tensions they might feel when the third dog, the youngest one, is in close proximity, perhaps closer than 12 feet away. From your observations, note well if any of the three dogs exhibits possessive aggression, also called resource guarding or object guarding of favorites things such as the sofa, the food bowl, the chew toys.  Note, also whether any of the three dogs tends to mouth you, put its mouth on you in a slobbery way, but often.

Here's a strong suggestion. For several weeks, keep the youngest dog apart from the others except for those special treat times I mentioned.

If necessary, devote your attention to that third dog in another room entirely. Reward her just tons for calm behavior, for relaxing in the presence of her food bowl, in the presence of a special treat. Perhaps whenever you give her chew treats, have her chew on them only when she is securely in a wire dog crate, at some distance from the other dogs. During these practice sessions, she'd be learning to take her direction from you, rather than taking matters into her own paws, so to speak.

You see, she's just a young dog yet, beginning adulthood. That's a time for some dogs to begin some strenuous testing to establish their place in the pack. Think adolescence, and you'll understand. Right now, she is not leaving the other two dogs alone and perhaps she never will do so unless when under your complete supervision. But you can teach Sandy to defer to you.

It sounds as if you could almost predict when aggressive episodes may happen at home, around favored possessions, so you have an excellent chance of preventing any such occurrence. You can build a daily regimen for yourself and the dogs with careful preventative techniques for every one's safety, then you have a very good chance to install the behaviors you wish to reward.

This job is important, not to be taken lightly. The plan will not work if we remember it only on certain days, say on Sunday and again on Wednesday afternoon. To learn their humans' expectations for their behaviors, we humans need to be consistent in the practice.  And practice we must, regularly.

Let me give an analogy. If I don't shoot baskets for 25 or 30 years, just how good a basketball player do you think I'll be? Or if I don't ride a horse for 40 years, just how good a horsewoman will I be? I may still have some muscle memory for those activities, but the muscles will be oh so weak.

Similarly, if we use good strategies to prevent the aggressive episodes for three to four months time, that would give us a window of opportunity to use that time well to teach each of the dogs some wonderful relaxing techniques. Do this as well for the third dog, while also teaching it the obedience skills and some fun activities to use its energy.  

Then -- in a way -- we'll be creating a new dog, one who has new techniques to use in daily living.  That happens because gradually we've replaced the game of exhibiting aggressive displays and practicing aggression for the dog to get what it wants. Now it has a new mannerly behaviors to use to get what it wants.

And you'll find that it's positively fascinating to watch these new dogs emerge, who suddenly begin to offer desired behaviors for a click/treat.

Why would they do that? Because, no doubt, they were simply practicing aggressive behaviors to learn how they worked for the dogs to attain their desired objectives. If the dog can attain those objectives in another way (i.e., find out what "works,") then the dog has a new repertoire of behaviors to use. As writer Jean Donaldson puts it, "How many dogs sit and beg at the refrigerator or at the freezer?" Not many, if no food ever jumps out of the refrigerator or freezer into their laps. They do, however, beg at the dining room table where there's a greater likelihood of food falling right near their mouths. That's an illustration that dogs do what works. They try out new behaviors all the time.

Aggressive actions are learned behaviors which can most definitely be modified. It will take some dedication and effort. But the task itself is not difficult once you understand the principles and how to apply them. You already have a good background in dog training, and you've helped your dog to succeed at obedience work.

When we're applying techniques to modify aggressive behaviors, one difference from regular obedience training is that perhaps we apply far greater contrast between an offered behavior we wish to reinforce and an offered behavior that we choose not to reinforce. 

We reward the behaviors we wish to reinforce; yes, indeed, we do. But we reward them very frequently. We use a high rate of reinforcement. And we reward these desirable behaviors heavily, with high-powered food treats. We want to build a very strong reward history for the dog.

Meanwhile, we use careful home management to prevent the dog from having the opportunity to aggress.

Then gradually, we re-introduce the dogs again, one at a time, for brief intervals under carefully controlled circumstances. You could take the youngest dog for a long walk on leash, perhaps to a woods nearby, and have another family member take along either of the other two dogs. Walk parallel to each other, but 20 feet away from each other, toward a common destination. If you focus on the task at hand, walking forward at a brisk pace, instead of ambling, then that will hold the dogs'  attention.

Also try to find some toys that interest this youngest dog. For retrievers, I like to use the canvas dummy. Those retrievers surely do love to hold something in their mouths! Use that desire. Use anything that comes naturally to the dog. The canvas dummy could be one of your dog's real life rewards for walking nicely on lead.

Let me just end with this remark: a huge factor in whether or not you'll see progress is owner determination to make a difference. I sense that owners who are asking how to end dog-dog aggression at home are truly determined to resolve problems and find the Peaceable Kingdom they've been hoping to achieve.

4/19/2001 Barbara D. Brill, North Chili, NY. All rights reserved. No further reproduction permitted without express written consent.