Fig. 1

Postmortem examination of stillborn foetus (animal No. 2). (A) Severe generalized oedema (anasarca) of the autolytic foetus. (B) Grossly evident cardiomyopathy featuring a severe dilation of both ventriculus and depressed reddish areas (red arrow). The lung showed melanosis (black spots), which is a usual finding of Iberian pigs with no disease implications. (C) Histopathological evaluation of the heart reveals foci of mononuclear inflammation (top left) and areas devoid of cardiomyocytes and replaced by fibrous tissue (bottom right). (D) Masson trichrome stain confirms the presence of collagen fibres (blue colour) in the fibrosed areas. (E) ISH against PCV3 reveals moderate amount of PCV3 genome (red staining) within the cardiac tissue. (F) Mitral valve, showing subendocardial infiltration of mononuclear cells. (G) Mesenteric arteries displaying lymphohistiocytic periarteritis. (H) In the same mesenteric arteries, ISH against PCV3 reveals abundant viral genome (red staining) in the arterial walls and -to a lesser extent- within the inflammatory infiltrate