In my observation, Brut's aggression is an exaggerated alpha dog correction. While watching the dogs try to chase a chipmunk under the deck, Brut had dug a huge hole on one side in an attempt to get underneath. The chipmunk would chirp from under the deck and both Brut and Zappa would get more and more excited. Brut continued to furiously dig, while Zappa ran back and forth. The only opening was the tunnel Brut was digging and Zappa could hardly resist himself. Zappa continued to press little by little into Brut's "territory." Testing his dad to see how far he could go. After I went inside to take a phone call, I heard the explosion of a fight. Usually they last for a second or two and it is over, but this time anxiety and excitement had pushed them both over. I had to pyhsically separate them. Corrections are useless at this point. It becomes a matter of getting them separated and giving them time to cool down.
It was easy to see that Zappa had crossed a very delicate line and is known for pushing the limits. Brut wasn't about to share in the glory of being so close to the chipmunk and was teaching Zappa a lesson. I in turn had to fill in and block the hole because I hadn't realized Brut had dug so far that the fence post had broke loose.
These type of fight happen are quite rare, but it does happen. It sounded and looked much worse than what it was. They both walked away without a nick or scratch on them. After blocking the hole I brought them both out and it was if nothing had happened. The high intensity of digging after this chipmunk brought on Brut's deep rooted issues of possession and territory. While Zappa in the excitement and belief that he can always press his dad limits set off the trigger that erupted into the need to correct Zappa.
If anything it was my fault for letting to go for so long. They had been after this chipmunk for a couple of days and I wasn't paying attention to how their energy had escalated. As I watched Zappa test his dad, it was apparent that it is was only a matter of time that something was going to happen as neither were about to give up. An episode like this is quite rare, so I missed the red flags that were starting to go off. When all was said and done everything was fine and they took off after the squirrels. At least the squirrels stay in the trees and don't give the dogs a reason to dig.