Ablutions (Wudu')
4/33.1. Chapter:
If a dog drinks from the utensil of any one of you then it is essential to wash it seven times
Sahih Bukhari
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِذَا شَرِبَ الْكَلْبُ فِي إِنَاءِ أَحَدِكُمْ فَلْيَغْسِلْهُ سَبْعًا ".
Narrated Abu Huraira: Allah's Messenger (ﷺ) said, "If a dog drinks from the utensil of anyone of you it is essential to wash it seven times."
Reference : Sahih al-Bukhari 172In-book reference : Book 4, Hadith 38USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 173