Lack of availability of commercial antibodies against whole-cell antigen or an antigenic epitope of Avibacterium paragallinarum (Av. paragallinarum) has hindered the development of novel immunoassays for the diagnose infectious coryza (IC). In this study, we raised polyclonal antisera against Av. paragallinarum and evaluated its antigenic-specificity using enzyme linked immunosorbent assay (ELISA). We standardized antigen coating concentration(s), antibody detection limit, and optimal range of dilutions of primary antisera and secondary conjugated antibody. Our results show the development of antigen-specific antibody response in rabbits following repeated antigenic exposure with 0.5% formalinized antigen over a period of four weeks. Further, we showed its possible applicability in detection of pathogens in tissues by immunohistochemistry for confirmatory disease diagnosis and disease pathogenetic study.