It turns out I was expressing a false belief.

I had falsely believed that calling Jews "dogs" was a long anti-Semitic tradition. I did more research and discovered that actually historically they were called rats and lice and very few examples exist of anti-semitics tropes comparing Jews and dogs.

The most salient example of that was an American trend to hang a sign on your shop that said "No Jews or dogs allowed", but that doesn't meet the standard of what I had believed.