Sahih Muslim 1575
Sahih Muslim · Book 22: The Book of Musaqah · The command to kill dogs, and its abrogation. The prohibition of keeping dogs, except for hunting, farming, (herding) livestock and the like
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (ﷺ) as saying:
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، حَدَّثَنَا عَبْدُ الْوَاحِدِ، - يَعْنِي ابْنَ زِيَادٍ - عَنْ إِسْمَاعِيلَ، بْنِ سُمَيْعٍ حَدَّثَنَا أَبُو رَزِينٍ ، قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنِ اتَّخَذَ كَلْبًا لَيْسَ بِكَلْبِ صَيْدٍ وَلاَ غَنَمٍ نَقَصَ مِنْ عَمَلِهِ كُلَّ يَوْمٍ قِيرَاطٌ " .
He who kept a dog, but not meant for hunting or watching the herd, would lose one qirat of reward every day.