Sayyidah Aishah Siddiqah (may Allah be pleased with her) narrates that the Prophet (peace and blessings be upon him) said: "Were it not that dogs are a particular kind of creation, I would have ordered them to be killed. But kill every pitch-black one among them."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains a narrator, Layth bin Abi Sulaym; he is thiqah (trustworthy), but he is a mudallis (one who conceals defects in the chain).