The reason I argue against a genetic basis of this neonatal liver failure is that since the sire and dam do not have liver disease. The mode of inheritance would have to be recessive. Against that is that 100% of the pups were affected. It wasn't stated how many pups there were, but that argues against a recessive disease gene.

One test, and this is just an educated guess, for an alloimmune mechanism is to take the sera from the dam and do a histological immunofluorescent stain of a slice of a pup's liver (or any pup's liver to demonstate antibody to a liver antigen. So in one sense it could be genetic and alloimmune etiology, if the particular MHC antigens on that mating resulted in an inappropriate immune response in the dam.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3940210/