Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah (ﷺ) said, "He who keeps a dog, will lose out of his good deeds equal to one Qirat every day, except one who keeps it for guarding the fields or the herd."[Al-Bukhari and Muslim].In a narration of Muslim, the Messenger of Allah (ﷺ) is reported to have said: "He who keeps a dog for any reason other than to guard his property (lands) or his flock of sheep, his good deeds equal to two Qirat will be deducted every day." (DE)
App reference (DE): Book 18, Hadith 179 (DE)
Arabic/English book reference (DE): Book 18, Hadith 1689 (DE)