"The Messenger of Allah said: 'whoever keeps a dog, two Qirats will be detracted from his reward each day, except a trained hunting dog, or a dog for herding livestock." (Using translation from Nasāʾī 4284)  

قَالَ رَسُولُ اللهِ ﷺ «مَنِ اقْتَنَى كَلْبًا نَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ إِلَّا ضَارِيًا أَوْ صَاحِبَ مَاشِيَةٍ»  

"The Messenger of Allah said: 'Whoever keeps a dog which he does not need for farming or livestock, one Qirt will be deducted from his (good) deeds each day.' It was said to him: 'did you hear this from the Messenger of Allah He said: 'Yes, by the Lord of this Masjid."' (Using translation from Nasāʾī 4285)  

وَقَالَ قَالَ رَسُولُ اللهِ ﷺ «مَنِ اقْتَنَى كَلْبًا لَا يُغْنِي عَنْهُ زَرْعًا وَلَا ضَرْعًا نَقَصَ مِنْ عَمَلِهِ كُلَّ يَوْمٍ قِيرَاطٌ» قُلْتُ يَا سُفْيَانُ أَنْتَ سَمِعْتَ هَذَا مِنْ رَسُولِ اللهِ ﷺ؟ قَالَ «نَعَمْ وَرَبِّ هَذَا الْمَسْجِدِ»