Figure 4

Ultrastructural detection of pulmonary platelet clusters in calves with and without pre-existing BVDV challenged with BHV-1.1. The analysis of the samples with transmission electron microscopy confirmed the presence of multiple aggregations of platelets within the blood vessels with some vascular lumina completely occluded (arrowheads) in the lungs of the BVDV/BHV-1 group at 4 dpi (A), versus a mild lesion (arrowheads) observed in the BHV-1 group (B). Pulmonary parenchyma showed recovery signs of this lesion (arrowheads) in the co-infected group at 14 dpi (C), in comparison with a total recuperation (arrowheads) in the single infection (D).