The only known mammalian prion is PrP, which noticeably affects animal behavior, and is detectable by testing lymph.  If the animal has prion-related encephalopathy, you burn it.<p>Viruses cannot reproduce without living cells.  Viruses that employ lipid capsids would likely be removed by the detergent along with the cells.  Some viruses do embed in a type of extracellular matrix (HTLV-1).  As far as I am aware, no research has been done on the transmissibility of viruses in decellularized animal organs from donor to recipient.<p>I presume that those facing imminent organ failure would rather catch a cold from a pig and recover in quarantine observation than die while waiting for such research to conclude.