Sahih Muslim Book 021, Hadith Number 4733.
Chapter : Hunting with the help of trained dogs.
'Adi b. Hatim reported: I asked Allah's Messenger (may peace be upon him) saying: We are a people who hunt with these (trained) dogs, then (what should we do)? Thereupon he (the Holy Prophet) said: When you set of your trained dogs having recited the name of Allah, then eat what these (hounds) have caught for you, oven if it (the game) is killed, provided (the hunting dog) has not eaten (any part of the game). If it has eaten (the game), then you don't eat it as I fear that it might have caught for its own self. And do not eat in case other dogs have joined your trained dogs.