Sunan an-Nasa'i, hadith 4280

أَخْبَرَنَا عِمْرَانُ بْنُ مُوسَى، قَالَ حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، قَالَ حَدَّثَنَا يُونُسُ، عَنِ الْحَسَنِ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ لَوْلاَ أَنَّ الْكِلاَبَ أُمَّةٌ مِنَ الأُمَمِ لأَمَرْتُ بِقَتْلِهَا فَاقْتُلُوا مِنْهَا الأَسْوَدَ الْبَهِيمَ وَأَيُّمَا قَوْمٍ اتَّخَذُوا كَلْبًا لَيْسَ بِكَلْبِ حَرْثٍ أَوْ صَيْدٍ أَوْ مَاشِيَةٍ فَإِنَّهُ يَنْقُصُ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطٌ ‏"‏ ‏.‏

It was narrated from 'Abdullah bin Mughaffal that the Messenger of Allah said:"Were it not that dogs form one of the communities (or nations - of creatures), I would have commanded that they be killed. But kill those that are all black. Any people who keep a dog, except for dogs used for farming, hunting or herding livestock, one Qirat will be deducted from their reward each day