Histomorphological changes in the base of the hoof skin in cattle with the development of Rustergoltz ulcer

The aim of the research was to study the pathomorphological changes in the tissues of the base of the skin of the hoof during the development of Rustergolz’s ulcer. The research was carried out in 2020, the object of the study was Holstein cows at the age of the second - third lactation with an average milk production of 10 500 kg of milk per year. For comparative characteristics, histological examination and detection of pathomorphological changes in the area of the ulcerative process, 25 deep samples were taken in the area of the base of the skin of the hooves with visible signs of the ulcerative process and 20 control tissue samples without signs of the ulcerative process. It was found that the normal histological structure of the base of the skin of the hooves is characterized by the presence of acanthotic cords extending from the surface deep into the dermis and having obvious signs of anastomosis with each other. In this case, the length of the strands varies significantly (from 0.1 to 4 mm), their width (up to 1 mm). A significant number of vessels (capillaries, venules, arterioles) were noted - up to 15 in the interval limited by 2 acanthotic strands. With Rustergoltz’s ulcer, paretic expansion of more than half of the venules is found with signs of plethora with simultaneous spasm of almost all small arteries, which may be associated with a loss of elastic properties of the deep layers of the dermis. Histological examination of samples taken from areas of extensive lesions showed the presence of a deep ulcerative defect that spreads to the papillary dermis in some cases with complete fusion of the stratum corneum, the presence of an interlayer of necrotic tissue, under which a thin, less than 0.5 mm, layer of immature granulation tissue is determined. In the epithelium of the acanthotic strands, pronounced dystrophic changes and the presence of migrating leukocytes are found.