: An Update Review about An Emerging Poultry Pathogen.

Respiratory diseases in birds generate sanitary and economic impacts and may be related to the environment and climate. , (ORT), , , , , and are among the most important avian respiratory pathogens. ORT is responsible for causing ornitobacteriosis, a disease characterized by clinical signs ranging from mild to severe respiratory conditions, with high mortality rates, mainly affecting turkeys and chickens.

Mycoplasma synoviae infection on Newcastle disease vaccination of chickens.

Newcastle disease is characterized by respiratory manifestations in association with nervous and/or digestive symptoms. Its prevention is done by vaccination with live attenuated (lentogenic strains) and/or killed vaccines. The lentogenic strains can lead to strong post-vaccination reaction, principally due to the presence of other pathogenic agents.