The announcement comes after tips led to raids around the city.
"They're bred by twisted, twisted people to become killing machines. And those people cannot be prosecuted hard enough, but you have to catch them first. And the only way to catch them is through programs like this," said Tom Dart, Cook County sheriff.
Animal fighting is a Class 4 felony in Illinois, punishable by up to three years in prison and a $50,000 fine.