Sayyiduna Adi bin Hatim (may Allah be pleased with him) asked the Messenger of Allah (peace and blessings be upon him) about game, and he mentioned the hadith, in which it says that he (peace and blessings be upon him) said: "If your dog joins other dogs and they kill the game without eating from it, do not eat anything of it, for you do not know which of them killed it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيد والذبائح / 18921