Field observations on a devastating respiratory syndrome in broilers in Pakistan

A respiratory syndrome causing heavy mortality in broilers is widespread throughout the country. It involves all ages of broilers mostly; layers are also susceptible. Initially there is sinusitis, followed by pneumonia, mucoid to haemorrhagic tracheitis and air-sacculitis. Mortality varies from 5 percent to as high as 70 percent. Target organs included all respiratory tract showing congestion, haemorrhages and necrosis. Tracheal epithelium contained basophilic intranuclear inclusion. Lungs showed multiple colonies of coco-bacilli. The disease appears to be virus-bacteria interaction.