Sahih Bukhari Volume 007, Book 067, Hadith Number 392.
Narrated By Adi bin Hatim : I asked Allah's Apostle. "We hunt with the help of these hounds." He said, "If you let loose your trained hounds after a game, and mention the name of Allah, then you can eat what the hounds catch for you, even if they killed the game. But you should not eat of it if the hound has eaten of it, for then it is likely that the hound has caught the game for itself. And if other hounds join your hound in hunting the game, then do not eat of it."