Musnad Ahmad 774:22

Yazid narrated to us, Zakariya ibn Abi Za'idah and 'Asim al-Ahwal informed us, from al-Sha'bi, from 'Adi ibn Hatim, who said: I asked the Messenger of Allah (peace and blessings of Allah be upon him) about hunting with a *mi'rad* (a blunt-headed arrow). He said: "Whatever strikes with its sharp edge, eat it; and whatever strikes with its side, it is *waqidh* (killed by a blunt blow)." And I asked him about hunting with a dog. He said: "When you send your dog and mention the name of Allah over it, and it catches [the game] for you, then eat. But if you find another dog with it, and it has killed it, and you fear that it may have taken it along with your dog, then do not eat, for you only mentioned the name of Allah over your dog, and you did not mention it over the other."