My female attacks her brother sometimes real bad and I'm usually the trigger. I'm not sure spaying her will change he but she his do soon. They are Karelian bear dogs with a thousand years of history. She ironically looks like a Tahltan bear dog which is extinct and her brother who is twice the size looks Karelian. She was the runt of the litter and was born with a chip on here shoulder. She defines the phrase its not the size of the dog but the fight in the dog. She's a mean little bitch towards all dogs but loves people. A buddy of mine said I should let them finish the fight but I'm worried about vet bills because once they are at it..its appearance looks like a fight to the death. I wanted to purchase a Cane Corso before I got them but saved them instead.