PRNP and scrapie: All three had clinical signs, pathology and PRNP genotype indicative of natural scrapie which was confirmed by the presence of vacuolation (Figure 1A) and PrPSc detection by IHC which showed prominent staining of PrPSc in the brain stem, especially in the DMNV (Figure 1B) and peri-vascular PrPSc immunostaining in thalamic nuclei, both typical for natural scrapie [32].