Respiratory form of infectious rhinotracheitis: Analysis of immunomorphological reactions

Abstract

The concentration of cattle in limited areas, nutritional disorders, and imbalance of micro- and macroelements contribute to suppression of natural resistance of the organism, insufficient live weight gain, leading to the growth of infectious diseases of young animals with high rates of forced slaughter and cattle mortality. The source of the causative agent of rhinotracheitis infection – Bovine alphaherpesvirus 1 hinders the development of the livestock industry, thus, it is necessary to search for possible approaches to prevent and control this infection. The purpose of the research is to determine the immunomorphological changes in the lymphoid tissue of the trachea and bronchial system, in the regional lymph nodes of the lungs and in the spleen in calves naturally affected by infectious rhinotracheitis. The experimental studies were based on the research of immunomorphological reactions in lymphoid tissue during infection of young cattle with Bovine alphaherpesvirus 1, using polymerase chain reaction, histological and immunohistochemical methods. According to the results, it was established that hyperplasia of tracheaassociated lymphoid tissue was observed in the trachea, and hyperplasia of bronchial-associated lymphoid tissue was observed in the lungs; the affected areas of the trachea and lungs were infiltrated with lymphocytes, macrophages and plasma cells. The immunomorphological reactions of regional lymph nodes demonstrate hyperplasia of B- and T-dependent zones, and in the spleen – hyperplasia of T-dependent zones of the white pulp. Thus, immunocompetent cells of lymphoid tissue associated with B- and T-dependent areas of the trachea, bronchial system of the lungs and regional lymph nodes of the lungs, and with T-dependent areas of the spleen, are directly involved in the pathogenesis of infectious rhinotracheitis of respiratory type calves. Antibacterial therapy with antibiotics destroys pathogenic and normal flora in the intestine, but they are not effective enough on viral infection, therefore, production trials of effective means of specific prophylaxis and vaccination are the primary task of veterinary medicine