Figure 5

Pathological findings in the experimentally infected lambs. (a) Focal thickening of the jejunal mucosa in a lamb from the 764 group euthanized at 150 dpi. Bar = 1 cm. (b) Focal lesion composed of a group of macrophages (arrowheads) seen in the interfollicular area of the JPP, observed in a lamb from group Ovicap49 culled at 390 dpi. HE. Bar = 50 μm. (c) Severe granulomatous infiltrate invading and modifying the lymphoid tissue architecture, that is also present in the related LP. JPP. Lamb from K-10 group with a multifocal b lesion, culled at 150 dpi. HE. Bar = 500 μm. (d) Diffuse lesion characterized by the thickening of the jejunal lamina propria with enlargement of the intestinal villi due to the presence of an infiltrate formed by several poorly-defined granulomas surrounded by numerous lymphocytes. Jejunum. Lamb from 764 group euthanized at 150 dpi. HE. Bar = 350 μm. (e) Two small and very well demarcated granulomas (arrowheads) present in the lymphoid tissue and adjacent lamina propria (multifocal a lesion) that do not significantly alter intestinal morphology. JPP. Animal from 764 group culled at 390 dpi. HE. Bar = 200 μm. (f) Detail of a “regressive” type granuloma, with a thick fibrous capsule surrounding the macrophages and giant cells, seen in the jejunal lamina propria in a lamb from 764 group culled at 390 dpi. Masson’s Trichrome. Bar = 70 μm.