Oy Vey! They used dogs to castrate jews.
(gab.com)
They started to push it immediately when the raping horde of good goys won over Germany. It didn't find much traction, so it was basically resting. ~1960+ they tried again and came up with all sorts of media. This was after a decade and a half of "denazification" programs running in Germany, so that the German population was afraid to say anything positive about Nazis or Hitler. So there was no real resistance to their lies any more, especially given that it would have been persecuted anyway, and specially that enough time has passed that they could come up with all sorts of bullshit and make up "evidence."