Since Vick dogfighting bust a renewed vigor to root out the blood sport, but law still weak

Police detectives and prosecutors around the U.S. say that despite being banned in all 50 states, the ancient blood sport of dogfighting is thriving in the underground, with hundreds of thousands of dollars at stake on big matches.

The spotlight of NFL star Michael Vick's 2007 case helped create more interest from police and federal investigators: the three largest dogfighting busts in U.S. history have occurred since 2009.

But state laws still require no minimum mandatory jail time, so while arrests and convictions can be disruptive to dogfighting rings for a short while, the practice continues to flourish.

Prosecutors in New York, Florida and other states say they need tougher penalties to help jail offenders.

Authorities say dogfighting isn't a regional phenomenon: arrest data collected by The Humane Society of the U.S. since 2011 show hundreds of busts in nearly every state.