Sunan an-Nasa'i, Volume 1, Book 2, Hadith 337 (DarusSalam) ⓘ
It was narrated from 'Abdullah bin Mughaffal that the Messenger of Allah commanded that dogs be killed, but he made an exception for hunting dogs and sheepdogs and said: "If a dog licks a vessel then wash it seven times and rub it the eighth time with dust."
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، - يَعْنِي ابْنَ الْحَارِثِ - عَنْ شُعْبَةَ، عَنْ أَبِي التَّيَّاحِ، قَالَ سَمِعْتُ مُطَرِّفًا، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَمَرَ بِقَتْلِ الْكِلاَبِ وَرَخَّصَ فِي كَلْبِ الصَّيْدِ وَالْغَنَمِ وَقَالَ " إِذَا وَلَغَ الْكَلْبُ فِي الإِنَاءِ فَاغْسِلُوهُ سَبْعَ مَرَّاتٍ وَعَفِّرُوهُ الثَّامِنَةَ بِالتُّرَابِ " .
also referenced under: Hadith 336 (Reference) & Book 2, Hadith 12 (In-Book)