I don't think blood pudding, blood sausage, or bludwurst normally contain any liver - thus they would not seem to have anything to do with liver sausage, liverwurst, or liver pudding except that they are all usually found in the form of a sausage. (By sausage, I mean an encased ground product not much larger than an inch in diameter.)
Bratwurst seems to have a wide variety of recipes. The "white hots" of western NYState are , I believe, a variety of bratwurst (or maybe weissewurst). Some bratwurst I've had seem quite livery, and some seem to have no liver at all, while some are very fine pates' and others quite coarsely ground.
Liverwurst and Laberkasse, in my experience, are usually rolls of finely ground liver and fat and spices about 4- 6 inches in diameter and stuffed in a natural casing. Laberkasse is usually eaten warm, while liverwurst is usually eaten cold or room temperature. Laberkasse keeps only a day or two in our refrigerator, while liverwurst is good for a week or so.
Then we can get into scrapple and livermush...
Cheers, John
I don't know what I was thinking when I wrote the above: Laberkasse always comes in a kind of meat loaf shape - it never has a casing.
John
<message edited by seafarer john on Thu, 11/5/09 6:03 PM>