Changes in structure of lymphatic organs in foals died due to Rhodococcus equi infection.

The aim of this study was to investigate the structure of lymphatic organs in foals which died due to Rhodococcus equi infection. The material for this study consisted of 9 foals, of both genders, various breeds, 6-14 weeks old. The routine histopathological examination and immunocytochemical reaction for cytokeratine-3 receptors revealed the disturbances in the thymus epithelial cells development. This was manifested by a complete lack of cells expressing cytokeratine-3 receptors, as well as absence of normal thymocytes differentiation. The supposed thymus epithelial cells were very few, expressing faint reaction of cytokeratine-3 receptors. The relative deficiencies in the lymphatic tissue development in peripheral lymphatic organs were observed. It was concluded, that the observed pathological changes may indicate the inherited, not described yet gene failure, which was responsible for the thymus epithelial cells developmental disturbances, and was expressed with various intensity in examined foals. The causes of the fatal course of rhodococcosis in foals were primary disturbances in the immune competence.