Microscopic changes in laying hens kidneys at the egg drop syndrome

The article presents the results of studying the microscopic changes in laying hens’ kidneys under egg drop syndrome (EDS-76). Clinical signs of EDS-76 in laying hens included decreasing of egg production, suppression, changes in egg pigmentation, laying of small-sized eggs with a soft shell, or without a shell at all. During the dissection enlarged, pale kidneys with clearly dilated blood vessels were registered. The lungs in most cases had an uneven red-pink color. In many laying hens, the spleen had an uneven color – it showed areas of different sizes and shapes of grayish, bluish, and red. In some cases, the liver was unevenly colored (with areas of yellowish and clay color), and in other cases, point and spoƩed hemorrhages were found under its capsule. However, the most pronounced and permanent gross changes registered in reproductive organs. During the histological examinations of the kidneys of laying hens infected with EDS-76 virus, we found that in this organ, there are specific for this disease and nonspecific microscopic changes, which are registered under the kidney damage of various etiologies. Specific for EDS-76 changes include the presence of basophilic and eosinophilic inclusion bodies in the nuclei of many epithelial cells in convoluted tubules, part of epithelial cells of straight tubules, and part of endothelial cells, podocytes, and mesangiocytes of the many glomeruli. Some of nuclei completely acquired distinctly oxyphilic properties. Nonspecific microscopic changes included diverse changes in nuclei and cytoplasm in epithelial cells of convoluted and straight tubules, violations of intercellular junctions, damages of renal corpuscles