Sayyiduna Abdullah bin Umar (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever keeps a dog other than a dog for guarding livestock, two qirats will be deducted from his reward every day." In Sahih Muslim, the hunting dog and the guard dog are exempted.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 11022