Assuming that I have correctly guessed the name of this dog, it's hard for me to believe that, even in the 1940s, the name was not chosen because it was considered amusing, and not in a nice way. I was born not that long after WWII and, I can assure you that that specific pejorative was not ever permitted in our home nor, indeed, any similar epithet referring to any ethnic or religious group. Period. That doesn't mean history should be erased, necessarily, but it is wrong to brush it off as simply a relic of a more 'innocent' time.