"I asked the Messenger of Allah ﷺ about the game caught by a trained dog. He said: 'If you mention the Name of Allah when you send your trained dog, then eat from what it catches for you. But if it eats from it, then do not eat it, for he only caught it for himself.' I said: 'O Messenger of Allah! What do you say about when our dogs get mixed with other dogs.' He said: 'You only mentioned the Name of Allah over your dog, you did not mention it over the others.'" Sufyan said: "He disliked for him to eat it."
سَأَلْتُ رَسُولَ اللَّهِ ﷺ عَنْ صَيْدِ الْكَلْبِ الْمُعَلَّمِ قَالَ إِذَا أَرْسَلْتَ كَلْبَكَ الْمُعَلَّمَ وَذَكَرْتَ اسْمَ اللَّهِ فَكُلْ مَا أَمْسَكَ عَلَيْكَ فَإِنْ أَكَلَ فَلاَ تَأْكُلْ فَإِنَّمَا أَمْسَكَ عَلَى نَفْسِهِ قُلْتُ يَا رَسُولَ اللَّهِ أَرَأَيْتَ إِنْ خَالَطَتْ كِلاَبَنَا كِلاَبٌ أُخَرُ قَالَ إِنَّمَا ذَكَرْتَ اسْمَ اللَّهِ عَلَى كَلْبِكَ وَلَمْ تَذْكُرْ عَلَى غَيْرِهِ قَالَ سُفْيَانُ أَكْرَهُ لَهُ أَكْلَهُ