The Book of Transactions (Kitab Al-Buyu`)
Muslim :: Book 10 : Hadith 3828
Sufyan b. Abu Zuhair (he was a person belonging to the tribe of Shanu'a and was amongst the Conpanions of Allah's Messenger [may peace be upon him ) said: I heard Messenger of Allah (may peace be upon him) as saying: He who kept a dog (other than that) which is indispensable for watching the field or the animals would lose one qirat out of his deeds every day. As-Sa'ib b Yazid (one of the narrators) said: Did you hear it from Allah's Messenger (may peace be upon him)? He said: Yes. by the Lord of this mosque.