From the article:
A total of 9 dogs were confiscated from the house, the dog fighting area, and 4 were found tied up in the woods behind the house. Two of the dogs died. The rest of them are at the Monroe County Animal Control Shelter. Five of them are pits, one is a pomeranian, and the other is a bulldog.It is likely that bulldog (if an English one) and the pomeranian were being used as bait, to goad a pitbull being used for fighting. Pitbulls are notorius for being easily trained as they want to please their people.
The dogs tied behind the house were being conditioned to pay attention, as they were likely being deprived of food and companionship. Also, once dogs are encouraged and trained to fight, you must untrain them before you can put them together in the same house again. Many former fighting dogs have been rehabilitated and gone on to be therapy dogs, so untraining them can happen. It takes time, patience and an experienced hand. Smilin' Pitbull Rescue in San Francisco has a lot of info about the breed, the aggression that can happen towards other dogs, and how to own a pitbull responsibly.