It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever keeps a dog that is neither for protection nor a hunting dog, then two qirats will be deducted from his reward every day." And the Prophet (peace and blessings be upon him) used to order the killing of dogs.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5775
Hadith Gradingحکم دارالسلام:إسناده صحيح، وأخرج منه الأمر بقتل الكلاب، مسلم: 1570.