If you are considering adding an additional dog to your household you should become very familiar with these articles. This information applies to all breeds of dogs. Highlighted or colored text indicates information that is more consistent when applied to Bullmastiffs than some other breeds.

In-Home Multiple Dog Management
Introducing a New Dog to the Resident Dog('s)
Canine Rivalry

In-Home Multiple Dog Management

Melinda Johnson
Copyright 1997

(with some Bullmastiff specific changes highlighted)

It's far better to AVOID fights then to try to break one up. There are some dogs that will never fight, but many perfectly good dogs will. Here are some suggestions for pack management with dogs who might fight:

1.) All meals are served in the dogs' crates, behind baby gates, or in separate, closed-door rooms. This prevents fights over food and also stops the 'piggy' dog from chowing down all the goodies out of the 'skinny' or shy dog's bowl. Nobody should be put in a position of defending their food. Mealtimes should be peaceful.

2.)  Any high value treats such as filled bones, marrow bones, pig ears, Buster cubes, filled Kongs, etc. should be given ONLY when the dogs are alone in separate crates or separate rooms.

3.) Never serve special treats unless you're right there to supervise all interaction. Never throw down new chew toys and then leave for work, leaving your dogs loose.

4.) Keep an eye on your dogs. Be aware of any strutting, stiff body postures, trying to get 'taller' over another dog, staring, or anything that could look like one dog is challenging another. If you see it, stomp your foot on the floor (noise interruption) and say (in your firm voice), "KNOCK IT OFF!". When this breaks up the behavior, immediately praise and love up everybody. Better yet, click and treat! Remove any object such as a food dish or toy that is causing the problem.

5.) Never, never, never champion and defend a beta dog because it's depressed at it's pack position or because you feel sorry for it!!! Do NOT mess with whatever the dogs think their pecking order might be.

6.) If a beta who is challenging an alpha dog for pack position keeps climbing into an alpha dog's crate and sleeping there, keep the crate door closed at night to prevent this. This is a classic challenge for pack position.

7.) Dogs are very competitive in a pack. This means they may have contests to see who can play harder, run faster, corner tighter, and other such games. As long as this remains friendly, it's OK. But keep in mind the whole picture of your dogs' lives together when you're evaluating the situation.

8.) Another time dogs are likely to fight is at the fence line when there's a distraction such as another dog on the other side of the fence, or even over who's first to answer the front door when guests arrive. You might think about this before you leave the house and leave dogs who have fought before loose in these areas.

10.) Make sure everybody gets their fair share of meals, treats, toys, petting, play, training and attention so there's no need to fight for these things.

11.) There are no absolutes.  

Every time pack management questions arise, several people will suggest that you allow the dogs to work things out alone. They'll assure you that this is the only way to go. Sometimes this can work, but this is dependent on the breed, individual temperaments and respective sizes of the dogs involved. Use your better judgment. Don't let a Rottweiller freely go at a Yorkie or a 2 year old pick on a 15 year old. Often these remarks are followed by someone telling how they lost a dog (evenly matched in breed and size to it's opponent) to a dogfight by following this philosophy.

My own decision is be informed, and to observe carefully and use my intuition. If I feel like standing back, because the tussle is mild, the dogs appear to be evenly matched, neither dog is too aggressive and there's little history of problems in that arena, I stand back. If one dog is being harassed repeatedly by another and the calm dog finally says, "Enough!", I let that be. I will put an end to the harassment myself if I think it's gone on too long. If I decide to intervene based on the gravity of the situation, my past observations watching tensions build, or because my instincts tell me to, I step in without guilt or doubts. The potential risk is too great.

Two males together in the same house can be a tricky proposition. For Bullmastiffs in particular, it is recommended that two males NEVER be allowed to be together unsupervised (and only under direct and careful supervision at ALL other times).  Extreme caution must be observed as well with intact females.  In many breeds, it's not recommended. Even in breeds reputed for getting along well, there can be two individuals (male or female) who have endless problems. The problems usually arise at the onset of sexual maturity for the younger or beta dog, but can happen between spayed/neutered dogs or bitches, at any time and for reasons you may never be able to fathom.  Opposite sexes are less likely to fight, but it can happen.

Remember that if you have more than two dogs, several dogs can gang up against one dog and may not stop until that dog is dead. Packs may turn on
their own if the victim is old or sick, and occasionally they will even turn on the very young. Protect puppies, geriatric, and ill dogs by keeping them separated from stronger pack members when you're away from home and with supervision when you are home.

Here's one thing you might try if you have one perpetrator and one victim. Do you wear a particular cologne or hand lotion? Try applying your scent to the victim for a week or two and see what happens. Dogs are VERY scent-oriented. You smell like love, warmth, food, water, all the good effect of stopping aggression and building friendships. This works with cats, too.

Remember that in a pack situation, a dog may act out by chewing, soiling, or displaying other troublesome behaviors. These may be a result of something you did, changes in living arrangements or schedules, additions or subtractions of family or pack members, or simply a response to another dog's actions. Sometimes it's hard to guess why things aren't going right, so don't always blame yourself.

Each dog is different. Each situation has to be independently evaluated. If dog fighting in your home is just an occasional nuisance, do what you need to do to live with it and prevent fights. However, if the situation is making your life or your dog's life miserable, be willing to carefully place a dog with another loving family and get back to having a harmonious home. Life's too short to be miserable, and your dog's life is even shorter. Make sure it's a good one. If you place one dog, be alert to changes in pack dynamics. Another dog might try to take the first dog's place as antagonizer. 

- Know in your own mind the differences between what you will tolerate and what you will not. Set your house rules and stick to them. It's your life, your house, and your dogs. Within the bounds of being reasonable and fair, within the bounds of humane treatment, it's your call.
- Don't worry about being alpha; just be clear within yourself and your dogs will know you are the boss.
- Keep learning.
- Observe your dogs carefully.
- When in doubt, it's better to be safe than sorry. Don't take risks, especially with a dog who has fought or bitten before. Use adult supervision, leashes, neutering/spaying, closed doors and gates, or whatever is needed.
- Experiment; if what you're doing isn't working, try something else. Try to give changes time to work.
- Use your clicker and treats to reward behaviors you like.
- Don't drive yourself crazy trying to figure out what a dog is thinking.
- Don't beat yourself up crying over mistakes you think you may have made. Life goes on.
- All's fair in love and war, and that includes breaking up a serious dog fight with a broom, or whatever means you can find. An emergency is an emergency.
- Be good to yourself. Take breaks. Take a bubble bath. Take a vacation.
- Don't do anything against your better judgment, no matter who said to do it. Trust your observation and intuition above all.

Top of Page


Keep them separated from one another initially, using crates.   There’s no point in setting the new dog up for failure.  If he’s quiet and good in his crate, reward him with treats for his good behavior, and simply ignore him if he’s putting up a fuss.  Use a baby gate to help keep the dogs separated through the initial introductory phase. 

Walk them separately in the beginning.

When one is crated and the other is free, reward them both with treats for good behavior and a calm response to the other dog.  Rewards work better and have a much longer impact on a dog than reprimands.

Feed one dog in his crate and the other in another room or another crate, so neither feels threatened by the other when there’s food involved.   The same advise applies to high value toys and treats.  Keep them separated and do not allow a rivalry to develop.

If there doesn’t seem to be a huge problem between them, you can begin to walk them together, on opposite sides of the street.  After that has gone well for several days, then you can allow them to meet on neutral ground, such as a nearby park.  If that goes well, then they can walk home side by side, and have their walks together after that.  It will still be too early to allow them to be together in the house – give them a few days of enjoying their walks together. 

Once that is going well and they’re looking forward to seeing one another, then you can carefully let them meet in the house, preferably when there are two adults present.  USE A LOT OF TREATS to reward them when they’re good, just be very careful not to inadvertently introduce food aggression at this point.  Give each of them the SAME treat at the SAME time and do not allow either of them to try to steal the other’s treat.  Collars and leads would be quite useful at this point, just so you have a way to maintain control of the situation if it appears to be getting out of hand.   Remember, outdoors is one thing – in the house is a totally different environment for a dog, and one or both of them might be protective about having an “invader”.  That’s why it’s important for them to get to know one another on neutral ground and to see one another in the house (but safely apart from each other) for a while.  It will be much easier on both of them (and you and your family) if you take the time in the beginning to introduce them carefully.

This can be quite a lengthy process – up to two months – so don’t rush the dogs into a situation that they might not be ready to handle.

Top of Page

Canine Rivalry

Copyright 2000. Dumb Friends League. All rights reserved.  

What Is Canine Rivalry?
Canine rivalry refers to repeated conflicts between dogs living in the same household. Animals that live in social groups establish a social structure within the group called a dominance hierarchy. This dominance hierarchy normally serves to maintain order, reduce conflict and promote cooperation among group members. Conflicts arise between household dogs when there is instability in the hierarchy, that is, when the ranking or social position of each dog is not clear or is in contention. Initially, dogs may only snarl, growl or snap without injuring each other. Sometimes, however, the conflict may intensify into prolonged bouts of dangerous fighting which may result in one or both dogs being injured.

Getting Professional Help
Ongoing canine rivalry is potentially dangerous since the dogs could be severely injured, as well as family members, if they become the object of redirected aggression when the dogs are fighting. Because resolving rivalry problems requires managing the dogs’ somewhat complex social behaviors, it’s often necessary for owners to obtain assistance from a professional animal behaviorist (see our handout: "When the Behavior Helpline Can't Help"). Animal behaviorists are trained to observe, interpret and modify animal behavior.

Why Conflict Occurs
Conflicts between household dogs usually develop when the ranking of each dog is not clear or is in contention. This may occur if:

You attempt to treat both dogs equally, rather than supporting the dominant dog’s position.
You interrupt or interfere with the dominant dog's ability to control the preferred items (food, toys, beds, attention) in his environment by giving preferential treatment to the subordinate dog(s).
You prevent the dogs from expressing the signals and ritualized behaviors that establish dominance.
A new animal has been introduced into the house.
A resident animal has died or no longer lives in the house.
A resident animal is re-introduced after an absence.
A young, subordinate dog reaches social maturity (usually between ten months and two years of age).
A dominant dog ages and cannot maintain his dominant status.

Understanding Dominance Behavior And Social Structure
You cannot choose which dog you want to be dominant. The dogs will establish this among themselves, and any attempt to interfere may result in increased conflict. Where each dog ranks in the dominance hierarchy is determined by the outcomes of interactions between the dogs themselves.

Determining which dog is dominant: Individual personality, as well as breed characteristics, are important factors. The dog that demands to be fed first, petted first and through the door first is usually the dominant dog. Remember that the rankings may be different in different contexts (one dog may control food, while another may control resting places) and they may change over time.

How dominance is established: Dogs usually establish their dominance hierarchies through a series of ritualized behaviors that include body postures and vocalizations that don’t result in injury. One dog may "stand over" another by placing his paws or neck on the shoulders of the other. However, because of past experiences, inadequate socialization or genetic temperament tendencies some dogs may, with very little warning, escalate dominance displays into aggression. If this occurs, call  your veterinarian for a referral to a professional animal behaviorist.

Dealing With Rivalry Problems
If the dogs involved are intact males or females, spay or neuter both dogs.
Determine each dog's dominance status relative to each other. Remember, this ranking is based on the behavior of the dogs, and not what ranking you prefer.
Support the dominance hierarchy. You need to support whatever dominance hierarchy or "pecking order" your dogs establish for themselves. Don't undermine their hierarchy by attempting to treat them equally or by preventing the dominant dog from asserting his position. Dominant dogs can, and should, be allowed to take toys away from subordinate dogs, to push in to receive attention and petting from the owner, to control favorite sleeping places, toys and other valuable resources (from the dogs’ point of view). Support the dominant dog's status by allowing this to occur.
Make sure that all of the humans in your household occupy the top of the dominance hierarchy by practicing "Nothing in Life is Free". This provides stability at the top of the dominance hierarchy, which will help the dogs sort out their lower places in the pecking order more peacefully.
Never, under any circumstances, attempt to break up a fight between dogs by grabbing their collars or inserting any of your body parts between them. If you feel you must break up a fight between dogs, do so by squirting them with a hose (outdoors), or squirting them with a vinegar/water mixture from a squirt bottle (indoors).

With the help of a professional animal behaviorist, elicit and reinforce non-aggressive behaviors using counter conditioning and desensitization techniques. These procedures must be designed and tailored to specifically meet the needs of each individual case and require professional in-home help.
You should be aware that if you respond to this type of problem inappropriately, you run the risk of intensifying the problem and potentially causing injury to either yourself, your dogs or both.

Punishment Will Not Solve The Problem
Punishment can actually make the problem worse. We encourage you to seek assistance from your veterinarian regarding: spaying and neutering your pet; evaluating the health status of your dogs; and for a referral to a professional animal behaviorist.

Top of Page