Sunan an-Nasa'i, Volume 1, Book 9, Hadith 751 (DarusSalam) ⓘ

It was narrated that Abu Dharr said: The messenger of Allah said: "When anyone of you stands to pray, then he is screened if he has in front of him something as high as the back of a camel saddle. If he does not have something as high as the back of a camel saddle in front of him, then his prayer is nullified by a woman, a donkey or a black dog." I (one of the narrators)said: "What is the difference between a black dog, a yellow one and a red one?" He said: I asked the Messenger of Allah just like you and he said:"The black dog is a shaitan."

أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ أَنْبَأَنَا يَزِيدُ، قَالَ حَدَّثَنَا يُونُسُ، عَنْ حُمَيْدِ بْنِ هِلاَلٍ، عَنْ عَبْدِ اللَّهِ بْنِ الصَّامِتِ، عَنْ أَبِي ذَرٍّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِذَا كَانَ أَحَدُكُمْ قَائِمًا يُصَلِّي فَإِنَّهُ يَسْتُرُهُ إِذَا كَانَ بَيْنَ يَدَيْهِ مِثْلُ آخِرَةِ الرَّحْلِ فَإِنْ لَمْ يَكُنْ بَيْنَ يَدَيْهِ مِثْلُ آخِرَةِ الرَّحْلِ فَإِنَّهُ يَقْطَعُ صَلاَتَهُ الْمَرْأَةُ وَالْحِمَارُ وَالْكَلْبُ الأَسْوَدُ ‏"‏ ‏.‏ قُلْتُ مَا بَالُ الأَسْوَدِ مِنَ الأَصْفَرِ مِنَ الأَحْمَرِ فَقَالَ سَأَلْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم كَمَا سَأَلْتَنِي فَقَالَ ‏"‏ الْكَلْبُ الأَسْوَدُ شَيْطَانٌ ‏"‏ ‏.‏