The puppy watched its owner leave dolefully from behind.

dolefully 是形容词 doleful 的副词形式，doleful 由名词 dole（悲伤、忧愁）加上形容词后缀 -ful（充满...的）构成，意思是"充满悲伤的"。dolefully 表示"悲伤地、忧愁地"。