Submitted to: Proceedings of North Central Avian Disease Conference
Publication Type: Proceedings
Publication Acceptance Date: 10/3/1999
Publication Date: N/A
Technical Abstract: Turkey coryza is a highly contagious upper respiratory disease of turkeys caused by infection with Bordetella avium. The disease impairs growth and increases the susceptibility of young turkeys to other infections. In addition, it is associated with vaccine immunization failure well into the convalescent phase of the disease, perhaps due to immunosuppression. Depletion of thymic lymphocytes and decreased T-lymphocyte blastogenesis response to mitogen are reported features of immune-cell changes in coryza-affected turkeys. The focus of the present study was to further characterize the histopathologic lesions produced in poults exposed to a purified dermonecrotic heat-labile toxin (DHLT) isolated from B. avium. Exposure of poults to DHLT produced severe tubular nephropathy and necrotizing pancreatitis. The lesions in these two organs were of severe enough character to precipitate mortality. In addition, DHLT also produced dlesions indicative of lymphocyte necrosis or apoptosis in the thymus and bursa of Fabricius. This finding suggests that DHLT produced by B. avium may promote immunosuppression in affected poults.