My fiancé and I adopted two dogs roughly 4 months ago; as they were bonded sisters who were abandoned by there previous owner. They have always gotten along and we have been able to keep them out of their cages while we go to work as they play together great. As of 2-3 weeks ago they have started viciously fighting to the point where they break skin on each other or us. They are truly difficult to break up and at times when we try to break them apart by picking one up the other one will come attached (via bite). Recently we have started putting them in cages to separate during the day when we leave, so they have time apart (see if that helps some).

The other concern is that we can typically tell when they are about to snap as there hearts start racing and they growl...then snap. We can't always catch it, but several times have been able to.

HELP!?!? Ideas on changing the behavior;