The Prophet ﷺ as saying: If anyone gets a dog, except a sheeping or hunting or a farm dog, a qirat of his reward will be deducted daily.  

عَنِ النَّبِيِّ ﷺ قَالَ مَنِ اتَّخَذَ كَلْبًا إِلاَّ كَلْبَ مَاشِيَةٍ أَوْ صَيْدٍ أَوْ زَرْعٍ انْتَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطٌ  

The Prophet ﷺ said: Were dogs not a species of creature I should command that they all be killed; but kill every pure black one.  

قَالَ رَسُولُ اللَّهِ ﷺ لَوْلاَ أَنَّ الْكِلاَبَ أُمَّةٌ مِنَ الأُمَمِ لأَمَرْتُ بِقَتْلِهَا فَاقْتُلُوا مِنْهَا الأَسْوَدَ الْبَهِيمَ  

The Prophet of Allah ﷺ ordered to kill dogs, and we were even killing a dog which a woman brought with her from the desert. Afterwards he forbade to kill them, saying: Confine yourselves to the type which is black.  

أَمَرَ نَبِيُّ اللَّهِ ﷺ بِقَتْلِ الْكِلاَبِ حَتَّى إِنْ كَانَتِ الْمَرْأَةُ تَقْدَمُ مِنَ الْبَادِيَةِ يَعْنِي بِالْكَلْبِ فَنَقْتُلُهُ ثُمَّ نَهَانَا عَنْ قَتْلِهَا وَقَالَ عَلَيْكُمْ بِالأَسْوَدِ