Sunan an-Nasa'i, Volume 5, Book 42, Hadith 4295 (DarusSalam) ⓘ
It was narrated from Abu Hurairah that the Messenger of Allah said: "Whoever keeps a dog that is not a dog used for hunting, herding livestock or guarding land, two qirats will be deducted from his reward each day."
أَخْبَرَنَا وَهْبُ بْنُ بَيَانٍ، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، قَالَ أَنْبَأَنَا ابْنُ شِهَابٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " مَنِ اقْتَنَى كَلْبًا لَيْسَ بِكَلْبِ صَيْدٍ وَلاَ مَاشِيَةٍ وَلاَ أَرْضٍ فَإِنَّهُ يَنْقُصُ مِنْ أَجْرِهِ قِيرَاطَانِ كُلَّ يَوْمٍ " .
also referenced under: Hadith 4290 (Reference) & Book 42, Hadith 28 (In-Book)