In the denouement of a three-year investigation, officials seized 367 dogs in what is being called the second-largest dog fighting raid in US history.

The FBI, the Humane Society, ASPCA (the American Society for the Prevention of Cruelty to Animals), and other state and national organizations took part in a joint operation in Alabama, Mississippi, Georgia and Texas. Arrests occurred in all four states, while dogs were seized at 13 locations in Alabama and Mississippi.

Ten suspects were arrested and indicted on felony dog-fighting charges, according to a statement issued by the Humane Society. Dog fighting is a felony in all 50 states and the District of Colombia.

The Associated Press reports that the suspects face multiple charges in connection with dog fighting and associated gambling, with each charge carrying up to five years in prison. Officials also seized firearms, drugs and half a million dollars in cash from dog fighting-related gambling activities which took place over the course of the three-year investigation, the Humane Society said.

"These defendants were betting between $5,000 and $200,000 on one dogfight," said George Beck, US Attorney for the Middle District Alabama. "The number of dogs seized and the amount of money involved this in case shows how extensive this underworld of dog fighting is. These dog fighters abuse, starve and kill their dogs for the supposed 'fun' of watching and gambling on a dogfight. Their behavior is deplorable, will not be tolerated, and will be punished to the full extent of the law."

The condition of the dogs, which the AP said were all pit bull terriers, varied. Many appeared to be emaciated. In one location, most all of the 114 dogs found in a single yard were tethered to chains in the middle of scorching summer heat with no fresh water or food anywhere in sight.

"Some appeared to have no access to water at all, and many exhibited wounds, scars and other conditions consistent with dog fighting," the Humane Society said. "Some dogs pulled at chains and cables that were tethered to cinder blocks and car tires. A female dog did her best to tend to six puppies, just weeks old, with no food or water, in a pen littered with trash and feces."

Some dogs were found dead, presumably losing contenders in the illegal dog fights.

Matt Bershadker, president and CEO of the ASPCA, said the raids ended the neglect and torture of hundreds of dogs.

"Never again will these dogs be forced to fight, live in squalor, or be neglected and deprived of the bare necessities," he said.

The dogs are now recovering at undisclosed locations.

The 367 dogs rescued in this US joint raid is second only to a larger, multi-state dog-fighting raid which took place in 2009, resulting in the rescue of more than 500 dogs. That raid too place across eight states and resulted in more than 100 arrests, according to the Humane Society.