Musannaf Ibn Abi Shayba 35:213

Khalid ibn Makhlad narrated to us, from Malik ibn Anas, from Yazid ibn Khusayfa, from al-Sa’ib ibn Yazid, from Sufyan ibn Abi Zuhayr, who said: I heard the Prophet, peace and blessings of Allah be upon him, saying: "Whoever acquires a dog that does not serve him for cultivation or livestock, a qirat of his deeds will be deducted every day." It was said to him, "Did you hear this from the Messenger of Allah, peace and blessings of Allah be upon him?" He said, "Yes, and by the Lord of this mosque."