Thus, the degree of inflammation in the tissues is inappropriately low for the degree of bacterial colonization and tissue destruction. The nasal discharge of this foal suggests that is has bronchopneumonia, or an airway-associated inflammation of the lungs. CID results in severe hypoplasia of primary and secondary lymphoid tissues, as shown in the following figures. This is a histologic section of a normal thymic lobule. There is no distinction between cortex and medulla.
Thymic lymphocytes are completely absent.
Only thymic epithelial cells and other stromal components are present. In a sense, the entire thymus of a CID foal resembles the thymic medulla of a normal foal. The normal lymph node is divided into cortex, paracortex, and medulla. Lymph node-normal animal Notice the lack of cortex, paracortex, and medulla. The remaining cells consist of fibroblasts, macrophages and perhaps NK cells.