Oprah Winfrey is to dedicate an episode of her talk show to her cocker spaniel Sophie who recently passed away from kidney failure at the age of 13.

AP released a transcript from the show, due to be broadcast on Friday, quoting Oprah as saying: "Sophie gave me 13 years of unconditional love. She was a true love in my life."

As part of the show, Lisa Ling will deliver an investigation on puppy mills which Winfrey declares is "for anybody anywhere who loves a dog, has ever loved a dog or just cares about their basic right to humane treatment."

She adds: "I would never, ever adopt another pet now without going to a shelter to do it. I am a changed woman after seeing this show."