"The Messenger of Allah said:' whoever keeps a dog except one that is trained for hunting or a dog for herding livestock, two Qirats will be deducted from his reward each day." (Using translation from Nasāʾī 4286)  

أَنَّهُ سَمِعَهُ يَقُولُ إِنَّ رَسُولَ اللهِ ﷺ قَالَ «مَنْ أَمْسَكَ كَلْبًا إلا كَلْباَ ضاريا أو كلب مَاشِيَةٍ نَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ»  

He who kept a dog other than one meant for hunting or for watching the herd, lost two qirat of his reward every day. (Using translation from Muslim 1574b)  

عَنِ النَّبِيِّ ﷺ قَالَ «مَنِ اقْتَنَى كَلْبًا إِلَّا كَلْبَ صَيْدٍ أَوْ مَاشِيَةٍ نَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ»