fealty

White Fangを見世物の闘犬にしたBeauty Smithから救ってくれたWeedon ScottにWhite Fangは恩を感じている様子です。
And so, because he needed a god and because he preferred Weedon Scott to Beauty Smith, White Fang remained. In acknowledgment of fealty, he proceeded to take upon himself the guardianship of his master’s property. He prowled about the cabin while the sled-dogs slept, and the first night-visitor to the cabin fought him off with a club until Weedon Scott came to the rescue.
"fealty" と、慣用句と思われる、 "take upon himself" を辞書で調べます。"fealty" はこの後にも次の個所に出てきました。
The team dispersed in ignominious defeat, and it was not until after dark that the dogs came sneaking back, one by one, by meekness and humility signifying their fealty to White Fang.
では　"fealty" の意味を辞書で見ます。
・Collins English Dictionary: (in feudal society) the loyalty sworn to one's lord on becoming his vassal
・Vocabulary.com: Stemming from the Latin word "fidelitas," the noun fealty is related to "fidelity," and is another way of saying "loyalty" or "faithfulness." Most school kids pledge their fealty, or allegiance, to the United States of America every morning in homeroom. But if you think fealty sounds like a word King Arthur would use, you're right: It's really an outdated term that primarily describes a vassal's sworn allegiance to a feudal lord.
人間なら忠誠と言ったところでしょうか？　渋谷の忠犬ハチ公が思い浮かびます。
"take upon himself" は明日取り上げます。