he article is devoted to the current problem of laboratory diagnosis of nodular dermatitis in cattle. Specific tools and methods for diagnosing t his disease have not yet been developed. There is evidence of an antigenic relationship between the causative agent of nodular dermatitis of cattle and the causative agent of sheep pox. The possibility of using means and methods of serological diagnosis of sheep pox for the diagnosis of ND cattle is being considered. Reducing the timing of diagnosis helps to increase the effectiveness of ongoing therapeutic and antiepizootic measures.

The production of vaccine preparations before release requires standardization of their immunobiological parameters, especially safety and immunogenic efficacy. An indicator of the immunogenic effectiveness of the lumpy skin disease vaccine is the resistance of vaccinated cattle against the virulent virus. However, according to preliminary studies, the virulent control virus did not always cause clinical disease with characteristic symptoms when infected subcutaneously. The purpose is to develop a biological model in the form of a complex consisting of a pathogenic virus, a method of infection and a susceptible animal to assess the immunogenicity of a lumpy skin disease vaccine. Local cattle, intact from lumpy dermatitis, were used to reproduce lumpy dermatitis and develop the causative agent of the disease. As the initial infectious virus, we used a 20 % tissue suspension of nodules (skin nodules) obtained from cattle that fell ill with lumpy dermatitis in the field in the Atyrau region in 2016. As a viral mass to control immunogenicity, a 20 % suspension of skin nodules and edematous skin tissue at the site of the pathogen injection, obtained after the “refreshment” of the virus in animals, were used. The disease was reproduced by infection with the test suspension of the virus intradermally, subcutaneously, intravenously at a dose of 0.5 cm3 and titration on the skin of the animal. The effectiveness of the biological model was assessed by morbidity, severity of the course and severity of the manifestation of the disease. During primary intradermal infection with a field isolate of the virus, the disease manifested itself in one of three animals in the form of hyperthermia, depression, lacrimation, and the appearance of several nodular nodules in the skin of animals. The refreshed tissue virus caused clinical disease both in subcutaneous, intradermal and intravenous infection. But the clinical signs of the disease were more pronounced with intradermal inoculation of the virus, and with intravenous inoculation, it manifested itself in a more severe form with a fatal outcome. Inoculation of the virus intradermally into different areas of the skin led to the development of an independent skin lesion in each infected point in the form of painful edema, followed by necrosis, the size and intensity of which depended on the dose of the injected virus. This development of skin pathology made it possible to work out a method for determining the virus titer in vivo. The tissue virus obtained from the edematous tissue at the site of the pathogen injection was guaranteed to cause clinical disease in cattle during intradermal inoculation and made it possible to evaluate the immunogenic efficacy of the produced batches of vaccine against lumpy dermatitis.