We adopted our "Abby", a pit-bull/boxer/beagle mix, from the North Shore Animal League in New York at 12 weeks old in February '07. After a quarantine period, we introduced her to her 'sisters': 15 year old Lucy, a dobie-mix, and 7 year old Carolina, a LARGE bloodhound/shepherd mix. At one point, during supervised play with Cara, she was nipped by Cara hard enough to draw blood (very small wound but there none-the-less).
Since around this time, there have been ten to twelve separate attacks on 'close-quarters' dogs; that is, dogs she has spent more than a day or two with. Including her housemates! These attacks are extremely vicious; she grabs hold of the neck or ear, clamps down and won't let go, shaking her head. She has attacked Lucy three times; Lucy is VERY submissive and these fights are relatively easy to break up. But her attacks on Cara seem to be to the death. Cara has always been very much the Alpha dog and it seems Abby wants the title. The oddest thing is that they play together in a harmonious manner most other times.
There are NO issues when she plays at the dog park...she is very good with all the other dogs there, although I've stopped taking her lately due to her unpredictability. She is walked several times daily, and spends some time on a dog run outside but primarily she's inside. My husband, son and I are home almost all the time. She was spayed before we adopted her.
If I'm watching very carefully, I can see the signs that she's about to go on the attack: she makes eye contact with the other dog, narrows her eyes, her body stiffens and BAM! If I'm nearby I can distract and isolate her, and I've been using the methods to reestablish Alpha dog human status (she had been allowed up on the furniture and beds) but I'm so afraid she'll have to go if I can't train her aggressiveness out of her!
There are NO food issues; I can feed all three of them in the same room with no problem. I can take her food or bones away with nary a growl. Abby loves people and cats and most other dogs. She is not shy, and we completed a basic obedience course two months ago. We need to reinforce the training as currently she seems to obey only when she feels like it. She is very people-oriented and loves to be petted by anyone. She's good with children, but tends to jump up on them if off her lead, not in an aggressive manner from in a play stance.
ANY suggestions would be most welcome!