Immunohistochemical studies on infectious laryngotracheitis in the respiratory tract lesions in naturally infected laying hens

In this study, naturally infected by Gallid Herpesvirus type-1 in laying hens to be diagnosed by pathological and PCR methods. Sixty pieces of hens were collected in coops from Central Anatolia region. After necropsy, routine pathological processes were applied to the trachea/ larynx, sinuses, lungs and air sacs. All organs were also stained by immunoperoxidase method, and PCR methods were applied to formalin fixed paraffin embedded (FFPE) tissues. Immunohistochemically, the positivities were seen in trachea/larynx (78.3%), sinuses (61.6%), lungs (45%) and air sacs (50%). Positive reactions were observed, in mucous and gland epithelia especially located at intracytoplasmic and rarely intranuclear. PCR positivity was observed in the trachea/larynx in 15 (25%) cases, in infraorbital sinus in 11 (18.3%) cases, in lungs in 8 (13.3%) cases and in air sacs in 6 (10%) cases following the tests performed. Following these results, it is easily concluded that histopathology and immunoperoxidase method can usable for diagnosing of the ILT. However, PCR results made by FFPE tissues showed that this method is not adequate to diagnose the ILT alone.