Submitted to: Proceedings of Northeast Conference on Avian Diseases
Publication Type: Abstract Only
Publication Acceptance Date: June 8, 1998
Publication Date: N/A
Technical Abstract: Subgroup J avian leukosis virus (ALV-J) infection is considered as a serious cause of mortality and other production problems in meat-type chickens. ALV-J causes primarily myeloid leukosis (ML) and to a lesser extent hemangiomas, renal tumors and other neoplasms. During the last three years, several strains of ALV-J were isolated from affected broiler breeder and commercial broiler flocks in the United States. Field observations suggest that ALV-J is gaining virulence, as losses in affected flocks are occurring earlier and at a higher rate. Alv-J, is gaining virulence, as losses in affected flocks are occurring earlier and at a higher rate. ALV-J induced ML was diagnosed in affected meat-type chickens at 4 weeks of age or older. Control of this virus infection is compllicated by the lack of specific diagnostics, the antigenic and molecular variation among strains, and the unusually high rate of horizontal transmission. Most recently, ALV-J infection and tumors have been diagnosed in two cases that involved chickens other than broier breeder and commercial broiler flocks. This paper is focused on the diagnosis, incidence and control of ALV-J infection in chickens.