This morning I finally did some searches to see what I could figure out.
The first place I hit was snopes.com, which quickly dispatched the "Blücher is (or sounds like) the German word for glue" theory. Their claim is that it's funny because Brooks and Wilder are parodying the old style horror film in which an ominous sound - like a clap of thunder - strikes at various points. In other words, it's even more subtle than the glue reference. While I believed them about glue, I wasn't so sure about the rest of their explanation.
The next place I hit was about.com, which ageed with snopes.com about the glue reference, but added the following:
On the other hand, if you look up Blücher, some German dictionaries do list the expression "er geht ran wie Blücher" ("he doesn't loaf around/he goes at it like Blücher"), but that refers to the Prussian general Gebhard Leberecht von Blücher (1742-1819), who earned the name "Marschall Vorwärts" ("[Field] Marshal Forward") for his victories over the French at Katzbach and (with Wellington) at Waterloo (1815). In other words, Blücher (or Blucher) is just a German surname. It has no particular meaning as a normal word in German and certainly does not mean "glue"!That seemed interesting, and it lead me to the full name of the general that might be at the heart of the story I was trying to track down.
The next stop was the wikepedia entry for the movie, which said, in part:
The entry gives a link to amazon.com for that quote from Brooks. In that interview, we read:
Every time Frau Blücher's name is mentioned, horses are heard whinnying as if afraid of her name. Many viewers mistakenly believe that Blücher means "glue" in German; however, Blücher is a well-known German surname. The German term for glue is der Kleber, or tierischer Leim for animal glue. Brooks suggested in a 2000 interview that he had based the joke on the erroneous translation, which he had heard from someone else.
Other than that, the only thing I cut was another "Blucher" and another whinny. [Whenever the name of Frau Blucher, played by Cloris Leachman, is mentioned, horses whinny and thunder cracks.] I thought we had enough. Before we started shooting, someone told me "blucher" means glue, so that's why I had the horses whinny. I'm not sure if that's true.Now, far be it from me to disagree with the producer, but it still seemed possible that the name Blücher would belong to a German general who had killed a lot of horses somewhere along the line. So I continued my digging, but this time looking for the General himself, rather than searching for movie related information.
A quick google search lead me to various places, but the most interesting - from the perspective of this quest - was answers.com. In just the first two paragraphs of their writeup on Blücher they document that he had three different horses shot out from under him, the third actually landed atop him. He wasn't found for two hours, but when he was rescued he reversed a retreat order and headed his troops off to Waterloo.
Clearly, Blücher was a determined man of action, and he was in charge of a lot of cavalry at various points in his career. In addition, he apparently had "a certain way" with horses, if getting three of them shot out from underneath his charging form is any indication.
So, while I cannot prove that General Blücher was the inspiration for the whinnying horses in Young Frankenstein, it still seems to be possible.
Alas I need to do other things now, so for the moment I'll leave it at that. Anyone with information about the German general is welcome to contact me and let me know just how far off the mark I am.