I think you might be confusing eugenics with white superiority, both of which were common enough concepts during H.P.'s time but not the same thing by a wide margin. Eugenics is the basic belief that males and females should be selected to breed together based on genetic superiority to produce superior children. There were a lot of eugenicists in Japan for one example. The practice fell apart because it didn't hold up well to indepth philosophic scrutiny (see the book The Case Against Eugenics which is now in the public domain), because we subsequently learned in the 1950s that genetoc traits just don't work that way, and because the 3rd Reich in WWII was heavily invested in eugenics as a justification for its doctrine of racial superiority.
Regardless, the cat we are talking about from the story "The Rats in the Walls" if anybody wants to look it up. Just yesterday, the Horrorbabble channel re-uploaded a very nice reading of it to YouTube. That cat is actually the hero of the story if you think about it.
@jackjonesnga,
Ultimately, I don't know how racist H.P. was inside of his own head. None of us do. He wrote some shady things about Jewdiasm early in his career, and then he married a Jewish girl, so make of that whatever you will.
What is clear is that some of his language has not aged well at all for a 21st Century audience. All of this language was -- we must remember -- in common usage and even polite during its own time. Twenty years from now, the language we use in 2019 might come to be considered insensitive or even villainous. Most of us will be around at that time and still have the option to adapt to changing cultural values. Being dead, H.P. does not have that option.