Sahih Muslim
The Book of Transactions (Kitab Al-Buyu)
Book Number: 010 / Hadith Number: 3811
Abdullah (b. Umar) (Allah be pleased with them) reported: Allah's Messenger (may peace be upon him) ordered the killing of dogs and we would send (men) in Medina and its corners and we did not spare any dog that we did not kill, so much so that we killed the dog that accompanied the wet she-camel belonging to the people of the desert.