Combined pathologies of the distal extremities in dairy cows

Abstract

Diseases of the distal extremities in dairy cows are a widespread pathology that leads to a significant decrease in animal productivity. They arise against the background of restrictions on the motor activity of animals, violation of diets, rules for the care of hooves and zoohygienic standards for maintenance. The structures of the distal extremities are combined into a functional complex of interconnected structures (joints, tendons, finger organ). With destructive changes in one of the structures, the rest also become involved in the pathological process, which leads to the chronization of the course of pathologies in this area. However, until now there has been no morphological confirmation of this concept. In this regard, the aim of the work is to study the macro– and microstructure of the organs of the distal extremities in dairy cows in conditions of intensive animal husbandry. Autosional material was studied (50 samples of the distal thoracic and pelvic extremities of dairy cows of the black-mottled Holstein breed). The methods of anatomical dissection and light microscopy were used. The research was conducted according to generally accepted methods. The micro-preparations were studied using Jenamed-2 and MicroScreen microscopes. Data on concomitant pathologies of the distal extremities in cattle were obtained: along with visually easily diagnosed disorders of the growth of the hoof horn and dermatitis, arthrosis of the finger joints was observed in all cases, especially pronounced in the hoof joints. Impaired horn growth is associated with dyskeratosis and parakeratosis. Joint damage is irreversible, due to the deep destruction of articular cartilage with its partial replacement by fibrous cartilage and connective tissue. There is reason to believe that the cause of such structural changes is hypokinesia and metabolic disorders in animals.