Rafi' bin Khadij bin Rafi' · The Book of Hunting and Slaughtering

"The Messenger of Allah said: 'whoever keeps a dog, two Qirats will be detracted from his reward each day, except a trained hunting dog, or a dog for herding livestock."

"Whoever keeps a dog. Except a dog for hunting or herding livestock, two Qirats will be deducted from his reward each day."