The title explains it all, is there a kosher substitute for blood sausage?*
Blood sausage is not kosher due to the inclusion of blood, the consumption of which is forbidden by Jewish law.
Yes, if you consider some kosher sausage to be a sausage, and therefore a substitute for a non-kosher sausage.
No, if you want a sausage which is "like" blood sausage. It's pretty much like itself, and not much else, other than "it's a sausage", in which case, see above.