Abstract
Ornithobacteriosis is considered as an important emerging respiratory disease of domestic and wild birds that caused by Ornithobacterium rhinotracheale (ORT) bacterium. The disease has been detected in some countries since 1980, later on it rapidly distributed worldwide. Ornithobacteriosis can transmit either horizontally or even vertically. Infection with ORT is mainly characterized by respiratory distress, poor performance, acute death and drop in egg production. However, the most characteristic necropsy lesions of dead turkeys and chickens are yoghurt like airsacculitis and pneumonia. Unfortunately, infection with ORT was misdiagnosed in most of poultry flocks due to similarity with other respiratory pathogens and the lack of the ideal protocols for diagnosis. Recently, some molecular and serological techniques are used to detect the infection. Treatment of ORT with antibiotics is very difficult and variable as a result of acquired resistance. Many types of vaccines have been developed to counteract such infection in broiler, layers and breeder chicken and turkey flocks. Inactivated, live and sub-unit vaccines have been used with satisfactory results. Thus, this review article aimed to address ornithobacteriosis, emphasizing the distribution, transmission, clinical picture, diagnosis and the control of the disease.

Key words: Diagnosis, Incidence, ORT, Treatment, Vaccination