Agressive Female Black Mouth/Muzzle Cur

Question
I have had this dog for at least a year, she's an adult now. I rescued her (& her brother) off the street as young pups. A week later I rescued a female boxer/pit fem. and they were all fine together-- until 6 days ago when the fem cur attacked the boxer/pit going out the door. I truly don't know what set the cur off. I know that they get excited (I have a bunch of other dogs too)when they go outside, and it gets worse if they've been inside too long.
The cur acts like nothing happened, and I don't trust her fully but I'm still attached to her despite her biting me because she hangs on me like a best friend. The wife hates her and this has cost us an $80 vet bill for the boxer/pit(so far). Obviously, WHAT do I do??

Answer
William, it sounds like the cur believes she is alpha of the 'pack.' You need to rob her of that status before there are more altercations. The first thing I'd recommend is "Nothing in Life is Free (NILIF)," which you can find tons of information about by searching for it at http://www.yahoo.com NILIF should apply to ALL of your dogs.

The second thing I would recommend is having both dogs spayed, if they are not already.

The third thing I would recommend would be for a trainer who has experience dealing with aggression to come out and see what s/he thinks about the situation. It's impossible for me to give good advice over the internet because, without being able to SEE the dogs in person, I cannot know for sure exactly what is going on.