"Dogfighting is a heinous crime. These are animals who want nothing more than to make us happy," said Brenda Barnette of the Seattle Humane Society, at a news conference on Tuesday.

Barnett said the group is offering a $5,000 reward for information leading to the arrest and conviction of any person who organizes dog fights, participates in dog fights, promotes dog fights or officiates at dog fights in King County.

"They have to be trained to be mean, and then they have to be treated and trained with cruel techniques to make them mean and make them fighters," Barnette said.

The announcement of the reward came after the arrest of NFL quarterback Michael Vick, who is accused of being the mastermind of a bloody dogfighting ring.

Prosecutors allege Vick bought a Virginia home for the sole purpose of breeding, training and fighting pit bulls.

Local officials said dogfighting happens here, too, but it involves close-knit groups that are hard for police to infiltrate.

"We have not yet captured, arrested or prosecuted a ring leader of these events but we know they are out there," Interim King County Prosecutor Dan Satterberg.

The Seattle Humane Society said about 80 percent of pit bulls that come to them are bred for fighting or have been raised cruelly.