ENOfficial
It was narrated that Ibn 'Umar said: "The Messenger of Allah (ﷺ) 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."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّهُ سَمِعَهُ يَقُولُ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ أَمْسَكَ كَلْبًا إِلاَّ كَلْبًا ضَارِيًا أَوْ كَلْبَ مَاشِيَةٍ نَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ " .
sunnah.com