Usamah bin Zaid (may Allah have mercy on him) narrates that I asked Hazrat Qasim (may Allah have mercy on him) that if a person sends his trained dog for hunting and it catches and kills the prey, but this person sees some other trained dogs with his dog, then what is the ruling? Hazrat Qasim replied that if it is known that the trained dog killed it, then he may eat it, and if he is unsure whether another dog killed it along with his dog, then he should not eat it.