Sahih al-bukhari:175 Chapter: What has been revealed regarding ablution? Book 4, Hadith 41

Narrated `Adi bin Hatim: I asked the Prophet (about the hunting dogs) and he replied, “If you let loose (with Allah’s name) your
tamed dog after a game and it hunts it, you may eat it, but if the dog eats of (that game) then do not eat
it because the dog has hunted it for itself.” I further said, “Sometimes I send my dog for hunting and
find another dog with it. He said, “Do not eat the game for you have mentioned Allah’s name only on
sending your dog and not the other dog.”