Sahih Muslim Book 24, Hadith Number 5248.

Chapter : Angels do not enter a house in which there is a dog or a picture.

Maimuna reported that one morning Allah’s Messenger (may peace be upon him) was silent with grief. Maimuna said: Allah’s Messenger, I find a change in your mood today. Allah’s Messenger (may peace be upon him) said: Gabriel had promised me that he would meet me tonight, but he did not meet me. By Allah, he never broke his promises, and Allah’s Messenger (may peace be upon him) spent the day in this sad (mood). Then it occurred to him that there had been a puppy under their cot. He commanded and it was turned out. He then took some water in his hand and sprinkled it at that place. When it was evening Gabriel met him and he said to him: you promised me that you would meet me the previous night. He said: Yes, but we do not enter a house in which there is a dog or a picture. Then on that very morning he commanded the killing of the dogs until he announced that the dog kept for the orchards should also be killed, but he spared the dog meant for the protection of extensive fields (or big gardens).