Malik related to me from Nafi from Abdullah ibn Umar that theMessenger of Allah, may Allah bless him and grant him peace, said,"Whoever acquires a dog other than a sheepdog or hunting dog, willhave two qirats deducted from the reward of his good actions everyday." (ID)
USC-MSA web (English) reference: Book 54, Hadith 13 (ID)
Arabic reference (ID): Book 54, Hadith 1778 (ID)