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.