The most frequent case however, remains incomplete and/or cyclic depigmentation that occurs in adult dogs with black nose: unhappily, the origin is still unknown.

• 成狗是黑鼻子的狗狗经常会发生不完全的残留，或者循环系统退色发生在成狗是黑鼻子的：很不幸，这种情况的原因没有找到。