Musannaf Ibn Abi Shayba 35:212

Affan narrated to us, from Sulaym ibn Hayyan, who said: I heard my father narrating from Abu Hurayrah, from the Prophet (peace and blessings of Allah be upon him), who said: "Whoever keeps a dog that is not a dog for crops, nor for hunting, nor for livestock, then indeed, a qirat from his reward decreases every day."