"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»