Liver Shunt PSS
The majority of Deerhound breeders test puppies bred by them for this fatal disease , sadly if it is found that a puppy is affected they are generally put to sleep, to date I have been fortunate to have never been put in this horrific position as I am not sure what I would do, likely I would keep the puppy myself until its quality of life was so bad I would then put to sleep , I would also be tempted to have the operation but a very good friend of mine who did said she would never do it again .
It has been proved hereditary in the Yorkshire Terrier and Irish Wolfhound ( see links) and personally whilst no research has been carried out within the Deerhond population in the UK to my knowledge, I think if the evidence is there within the Wolfhound, Yorkshire Terrier, Maltese terrier ,so why would it not also have a hereditary pre-disposition in the Deerhound?, this is my opinion and may not be shared by others.
The problem is, whilst an affected puppy can be put to sleep, this does not stop any further breeding from the Mother/ Father or siblings so the gene will continue to thrive until Veterinary research is conducted and a screening test developed ( wouldn't that be fantastic) , full disclosure needs to be encouraged when breeders are deciding upon a litter or the use of a stud dog, this would allow people to make educated choices, again if the parents, sibling are omitted from the general gene pool this can tip the scales to more heart, bone cancer etc in the Deerhound, so all has to be considered when making the choice of Father and Mother http://www.ncbi.nlm.nih.gov/pubmed/19496918
another excellent link
Please read the links listed below, which will hopefull educate and allow more informed choice
Increasing incidence of hereditary intrahepatic portosystemic shunts in Irish wolfhounds in The Netherlands (1984 to 1992)
Liver shunt info University of Tennessee
Angel Fund for Research & Treatment of Congenital Portosystemic Shunts in Dogs
Recognition and Management of
Portosystemic Shunts in Dogs