When a dog licks a utensil belonging to any one of you, (the thing contained in it) should be thrown away and then (the utensil) should be washed seven times. (Using translation from Muslim 279a)  

قَالَ رَسُولُ اللهِ ﷺ «إِذَا وَلَغَ الْكَلْبُ فِي إِنَاءِ أَحَدِكُمْ فَلْيُرِقْهُ ثُمَّ لِيَغْسِلْهُ سَبْعَ مَرَّاتٍ»