01/10/2014 09:30 am ET Updated Jan 25, 2014

James Guiliani, Former Mafia Man Turned Animal Rescuer, Stars In New TV Series 'The Diamond Collar' (VIDEO)

For 20 years, James "Head" Guiliani was a street enforcer for the mob, working for John Gotti and his crew in Brooklyn. "I used to deal cocaine, I used to deal marijuana, I used to stick people up," Guiliani recalls in the video above. Then, an encounter with a stray dog changed everything.

While he was still a gangster, Guiliani came across an abused and abandoned pup named Bruno. "He was sick, he was dying," Guiliani says. "Maggots were crawling through his skin."

Guiliani successfully nursed Bruno back to health. When Bruno later passed away, Guiliani decided he could never go back to the life he lived. He had found a new purpose and left the mafia.

Though he still works in Brooklyn, Guiliani's days of substance abuse, crime and serving time are far behind him. Today, he and his wife, Lena Perrelli, dedicate themselves to rescuing and rehoming abused and abandoned animals throughout the borough. The couple also runs a top dog-grooming parlor in Brooklyn called The Diamond Collar -- also the name of their new reality show premiering on OWN on Jan. 17.

"Brooklyn knows us for our amazing grooming, but best of all, we also rescue animals," Guiliani explains. "Any animal, any time, any situation."

Get a first look at the series in the video above and learn more about the mafia-man-turned-rescuer.

"The Diamond Collar" premieres Friday, Jan. 17, at 10 p.m. ET on OWN.