The issue of pack mentality in domestic dogs is a hot topic. There are a million different theories out there about how we think it works and what we should do to keep things stable and in order. While in a wild wolf pack, we can see that there is usually an alpha male and female, sometimes a beta or two and multiple subordinates, it's hard to transfer this into the domesticated and cross-species situation of multiple dogs living in a home with humans. Instead of taking any theory as 100% truth, the best idea is to take everything with a grain of salt and observe what your dogs are actually doing. John, Kelly and Susie's behavior will be your best clue into how their particular pack mentality works.
One thing that's well accepted by almost all pack mentality techniques is that the humans should be considered the "alphas" of the pack-even your youngest children rank above the oldest dog. This is for safety and practical reasons for both you and them. Dogs who know their place in line won't act aggressively or challenge you for power. Without harming or yelling at your dog, your 5-year old should be empowered to be alpha over all your dogs.
Some Easy Ways to Show Your Dogs that You are Alpha
So to begin with, one of the most important things you can do to assert your role as alpha is to control feeding. In the wild, the alpha male and female are always the first eat. So don't just lay out food whenever and allow John, Kelly and Susie to choose their eating time. Instead, choose a time or two times (depending on how often you want to feed them-if you have questions, ask your vet) and enforce start and finish times. An ideal time would be at the same time you and your family eat a meal. This way, the humans can sit down to eat dinner first, which dogs can see and smell, and only after you do this will you open their food and give them their dinner. Allow everyone in your home to control the feeding at some point.
This controlled feeding clearly establishes that humans rank above the dogs, and that as controller of the food, you are their alpha leaders. After a designated amount of time, take the food dishes away. Make sure all the dogs see you put down and take away the food. It's also an even better idea to have them all sit and stay while you prepare the dishes and only start eating on your command. It just further emphasizes that you are the one in charge.
When it comes to the rank order in the dog pack themselves, this should occur naturally-this is where observing their behavior will come into play. If all of the humans rank as alpha, then the most dominant dog will be considered beta, and he or she will be the leader of the others. If you notice that Susie seems to bully the others a bit, eat before them, or that they show her their bellies or get into submissive poses if she challenges them about a bed or toy, then these are the signs that they consider her the beta.
Depending on Susie, John and Kelly's breeds, ages and personalities, you may see this happen or you may not notice it at all. Some dogs are naturally more aggressive, and if this is the case they're more likely to fight for a beta role. Other dogs will live in relative harmony without needed to assert dominance in this way. But if you do notice that Susie is the beta, it's best for you to reinforce the order they established by allowing her to eat first, leave the house first on walks, or get pet first. If not, you may upset the natural order and cause John or Kelly to think they have a shot at being beta, which could lead to aggression. And that's something no alpha human should tolerate.
It is really important to let your dogs work this order out on their own, as they would in the wild. Human intervention is not needed and only serves to confuse everybody.