4.5 years ago I rescued Luke. He is a great Dane - bull mastiff. Three weeks ago a couple asked us to adopt their male great Dane, Jax and their female Dane - mastiff Jade. They didn't want the two separated. Jade is 3 yrs old and Jax is 2.5. They are Kennel trained and wonderful family members. Our problem is Luke. He is 6.5 yrs old and very spoiled (and dominant). We finally have the 3 of them in general population but Luke wants to hang his head over the other dogs in a dominant manner. Jade and Luke were passing in the door and war broke out. Both have battle bites but they did separate after I yelled. I am sure there is a better way to handle this... Please help we are keeping all three battle scars or not... so they need to get along! Any advice will be appreciated.
Wow, what a dog lover you are...3 large dogs in one household! While living with multiple dogs is a wonderful experience (I have multiple dogs myself!) sometimes problems develop, especially early in the relationship. Thankfully, most dog-dog relationship problems can be overcome, but the first step in these kinds of situations is always the same; prevent another episode by identifying the circumstances surrounding the incident/s (aka "triggers") and manage their environment accordingly.
Your letter doesn't mention it so I wonder, are all of the dogs altered (meaning spayed/neutered)? If the answer is "yes" - great, if "no" you need to have that done - pronto! Here's an article on the topic of neuter/spay and effects on behavior http://www.huffingtonpost.com/sophia-yin/does-spaying-or-neutering_b_272030.html
The next consideration is whether Luke or Jade have any health issues. Since the incident happened as the dogs were close to one another in a tight space, it's possible that they bumped into each other and If that caused a painful event for either of them, it could have caused, or contributed to the incident. It's important to have each dog examined as soon as possible to be sure that there are no medical (possibly painful) issues present.
You only mention this one fight, so again the key at this point is to be proactive, and from now on avoid putting them into that situation. Small spaces (especially given their size!) are a potential trouble spot, so have them go through doorways or other tight spaces individually - the dogs can be trained to sit/wait, or stay until you release them one at a time.
I understand that you have had Luke for 4.5 years but don't be fooled into believing that should entitle him to preferential treatment from you in the company of the new additions - if you treat him that way, he can learn to expect it, and when things don't go his way (which is bound to happen!) you could have an even bigger problem!
Domesticated dogs do not form rigid hierarchies or "packs" where there is one "alpha/dominant dog" who reigns over the group, as it was once believed. In fact, results of original studies done more than 40 years ago on wolves and their behavior - which is where the notion originated, and than transferred to domestic dogs - have been completely invalidated over the past 5 decades. Click here for information from David Mech, one of the world's leading researchers on wolves and their behavior http://davemech.org/ He addresses the research originally done on wolf populations and how it was conducted on captive groups, wherein their natural instinct to break off from the breeding pair to form their own packs was impossible. These unnatural conditions produced great conflict within the groups. Unfortunately, those early studies produced flawed results - that are still held as true today. Subsequent studies done on wolf populations under natural conditions, produced very different results, and in the process, completely transformed (and invalidated!) the notion of a "dominant alpha dog!
Modern research also supports the notion that domestic dogs' social relationships involve dynamics that are much more fluid than rigid, and often change depending on the situation. Click here for an article called "The Mythical Alpha Dog" by Dr. Ian Dunbar. You'll see that trying to determine who's "alpha" to support that dogs "status" (providing preferential treatment such as first access to food, water, petting/affection, allowing him to "steal" the others bones, chews, toys, etc.) will make things a whole lot more difficult for you, and can even create conflict between the dogs that would otherwise not have developed.
Read the information at Dominance and the alpha dog MYTH for more on the subject.
Of course it's important, for the dogs to learn good canine manners with one another in order to live together peacefully. In my experience working with resident dog relationship problems, there's almost always a "pushy" dog in the situation! We'll refer to this dog as "Dog A". S/he's the one usually stealing - or attempting to steal the other dog/s stuff. "Dog A" is the one most people perceive as "dominant" when actually s/he's just simply learned to repeat behavior that works for him. Fights break out when the other dog - "Dog B" has had enough - or decides he'd rather not give up his possession this time, and if growling, baring teeth, stiffening or other canine "warning" signs from "Dog B" to back off are ignored by "Dog A" (or by you!) some kind of physical conflict is often the result. Of course, if "Dog B" never resists and always gives up and walks away, you won't see actual fighting, but the reality is that eventually there will be that one time where "Dog B" isn't going to be so willing to give up his prize!
It should be clear by now that stealing between the dogs - or attempts to steal what the other dog has is a definite no-no that should not be allowed. If you allow this, you're leaving them little choice but to have conflict.
Resources like chews, favorite toys, meals, etc., are a very common source of conflict between canine housemates! I suggest that you feed the dogs separately - completely away from one other. Separating the dogs during "meal prep" times is also a good idea - it's a common time for trouble too!
Although this was already mentioned, it's worth mentioning again - Do not allow "visiting" or "stealing" (or attempts to steal) of possessions between the dogs - as this will almost surely cause problems. Interaction between the dogs should be relaxed and comfortable, not tense and stressful!
As for training, here's the link to a great article on how to (clicker) train effectively and safely, in a multiple dog household http://www.clickertraining.com/node/3118
You can also read more on the subject of problems between dogs who live together at this link; Housemate Problems
If the dogs continue to have issues, do not wait to call a professional for help. The earlier you catch a problem the better your chances of seeing the dogs live peacefully together! Research a qualified positive reinforcement trainer in your area. The Woofology website is home to several articles on what to look for in a training professional that you may find helpful.
We wish you the best, and thanks for writing!
Lisa Patrona, Dip CBST, CPDT-KA, ACDBC, AABP-CDT