Horo calls Lawrence "mushy-o" (phonetics), which in the translation I'm watching is translated to "Master", which seems strange for a proud wolf. I've never heard that word before, though I understand that there are several ways to say "Master". Most of them are "Go shu jeen" (phonetics) or related though.
Is the translator wrong? If not, why does Horo call Lawrence Master?
Disclaimer: I'm no expert in Japanese, just a die hard fan of Spice and Wolf.
Holo speaks in a dialect known as "Oiran" that often replaces the common "Watashi" to "Wacchi" among other things. The creator of Spice and Wolf, Isuna Hasekura-sensei made a few adjustments here and there so Holo's dialect is loosely based on it. There has been a bunch of people in the past discussing this here (a reddit post).
Additionally, you can see in an interview with Isuna Hasekura-sensei here where He mentions Holo's unique speech pattern (which is antique in a way), and the fact that this unique way of talking is often lost/corrupted in translation.
When Holo says "Nushi" it roughly translates to "You" when taken into the correct context. Many translators translate the word "Nushi" to mean "Master/Valued Customer", because the word "Nushi" is more commonly used by Courtesans (back in the day) to greet their guests.
