Infectious Bursal Disease (IBD or Gumboro disease) is an immunosuppressive birnaviral infection that causes high mortality and reduced growth rate, mostly in 2-6-week-old chicks. The disease is prevalent in chickens and turkeys and severity of clinical signs is dependent on bird age, breed and maternal antibody levels, as well as on viral virulence. IBD is diagnosed by PM and serology testing. Effective control of the disease can be obtained by appropriate live and inactivated vaccinations (that induce high levels of maternal antibodies in the chick) and good hygiene.