Hi I have 2 bostons as well (aren't they the best dogs!). Beenie is female 7, Frankie is male, 6, both fixed. The dominant dog had always been Beenie (smaller female) until Frankie got to be about 2 years old and 7-8 lbs heavier than Beenie. It's strange, when we visit my MIL, Beenie seems to take over as dominant dog at her house. She steals Frankies food and 'puts him in his place' if he starts barking. It's really strange to see the dinamics of the relationship depending on where we are. I hope your two quit fighting. Let us know how the dog whisperer training goes.