The Messenger of Allah ﷺ said, "When a dog drinks from the vessel of any of you, let him wash it seven times."
حدثنا محمد بن يحيى حدثنا روح بن عبادة حدثنا مالك بن أنس عن أبي الزناد عن الأعرج
أن رسول الله ﷺ قال إذا شرب الكلب في إناء أحدكم فليغسله سبع مرات
Bukhari transmitted it in the Book of Wudu, chapter "If a dog drinks from the vessel of one of you, let him wash it seven times," hadith no. 172, and Muslim in the Book of Purification, chapter on the ruling of a dog's licking, hadith no. 279, both from the hadith of Malik, with this wording.