The Diagnosis of Very Virulent Infectious Bursal Disease in California Pullets.

The article discusses a study which examined the occurrence of a very virulent infectious bursal disease virus (vvIBDV) in Northern California commercial brown pullets. Particular focus is given to flock mortality from the affected house at two neighboring ranches. IBD-affected birds exhibited lethargy, ruffled feathers, as well as postmortem lesions. The economic implications of IBD include a decrease in egg production and egg quality, immunosuppression in young chickens and impaired efficacy of vaccination. Results of the study showed that mortality in specific-pathogen-free leghorns inoculated with vvIBD strain can range between 25% and 100%. It also found a possible correlation between the degree of pathogenecity and lesion production in nonbursal organs.