I found this information regarding a miniature schnauzer, I will look for more. I lost a little dog due to liver shunt (possibly) and felt compelled to find information on it as well. I am very sorry for your loss.
www.vetinfo4dogs.com/dinherit
Congenital renal failure syndromes
Q: I am trying to get some information on Juvenile Renal Failure mostly as it applies to Miniature Schnauzers. What are the hereditary factors? I am assuming that it is hereditary. Thanks C-
A: There is a familial renal disease of miniature schnauzers, which is presumed to be heritable based on the pattern (related dogs being affected). I do not think the mode of inheritance has been established, nor is it certain that this condition actually is inherited. Despite this, it is probably not a good idea to breed a relative of a dog with this problem.
In most congenital renal failure syndromes the clinical symptoms of congenital renal disease do not usually appear before 4 months of age and may show up later in life, perhaps as late as two or three years of age. Typical signs of renal disease, including vomiting, weight loss, dehydration, increased drinking and urination occur. Anemia occurs as the disease progresses. While it is possible to slow the clinical course of these diseases with treatment it is eventually fatal. I am not sure if this is all true for schnauzers with congenital renal disease since I really only found a reference to the existence of the problem as a familial trait in Dr. Morgan's text " Handbook of Small Animal Practice".
Michael Richards, DVM