Abu Dawud Book 10, Hadith Number 2845.
Chapter : On game.
Narated By Adi ibn Hatim : The Prophet (PBUH) said: Eat what ever is caught for you by a dog or a hawk you have trained and set off when you have mentioned Allah’s name. I said: (Does this apply) if it killed (the animal)? He said: When it kills it without eating any of it, for it caught it only for you.
Abu Dawud said: If a hawk eats any of it, there is no harm (in eating it). If a dog eats it, it is disapproved (to eat the meat). If it drinks blood, there is no harm (in eating it).