Do you have any examples of a species rendered extinct by a plague in nature?

Recent observations, not fossil record or ancient history. And extirpation of a connected population from its (substantial) range is an OK proxy.

My first thought, off the top of my head, is Dutch Elm Disease, which developed in Asia, where the trees grew tolerant of it, but then spread to other areas, where the trees had no resistance. Non-Asiatic elms aren't extinct yet, but I think the two options are either: 1) Saved via human intervention, genetic modification, etc., or 2) The susceptible breeds will eventually go extinct as it spreads.

And extirpation of a connected population from its (substantial) range is an OK proxy.

I'm not a paleontologist, but don't we see species suddenly vanish from their ranges all the time even excluding the mass extinction events? How do we know that some of these extirpations are not pandemics?

Well, the time period then is quite small. Moreover, we're currently inadvertently killing so many species, that a handful being killed by disease could just get lost in the noise. I suspect there aren't any, but it isn't clear how to test that.