An excited dog is very eye appeasing--they have big smile on their face, their tail (or whole body!) is wagging around, they have a prance in their step, might do some jumping up, and even some excited barking. As a human, when we see a dog we start pumping him up to be like this, because we want our interactions with our dogs to be so exciting--a celebration!--because it makes our dogs happy! When we see them in the morning after waking up--a celebration! When we get home from work--a celebration! When it's time to go on a walk, eat a meal, or even just walk from one side of the house to the other--it's a dog-celebrating parade of bouncy dog!
Now, here are some behaviors we don't like from our dogs--jumping on us or guests, barking, pulling on the leash, acting crazy in the house, stealing food from the table, chasing the cat, etc.
Okay, so let's say you put your excited, celebration-having, dog beside a mirror image of himself practicing some of those undesirable behaviors-- you would see the exact same dog, making the exact same body movements, because he is giving you the exact same energy. Over adrenalized dogs make bad choices, and when every interaction with our dog is that exciting, they begin to live a life of constant high-drive adrenaline. Our dogs give us the behavior we encourage, and if every day tasks are celebrated with trumpets blaring, then every behavior your dog is going to practice will have roller-coaster adrenaline and speed to it.
You know that feeling you get when someone tickles you to the point you are laughing so hard, you can't breathe? We all know that feeling--what a rush! When we amp our dogs up with excitement, they are having the exact same feeling. All the time, every time.
Can you imagine doing that to your spouse, child, sibling, or parent every time you saw them, multiple times per day? Death by tickles?! That's crazy! So why are we doing it to our dogs?
If you start to give your dog calmer behaviors, you'll get a calmer dog in return.