Inclusion body hepatitis (IBH), caused by Fowl Aviadenovirus (FAdV), is a significant disease affecting chickens worldwide.FAdV-11 associated with IBH was identified in 9-day-old commercial broiler breeders in Brazil.The chicks exhibited a sudden increase in daily mortality, accompanied by nonspecific clinical signs, in one house on the farm.The cumulative mortality rate reached 11.
13 % by 15 days of age.Macroscopically, the liver was markedly enlarged and pale red with a distinct lobular pattern.Histologically, the liver showed mild to severe multifocal coalescent vacuolar degeneration and CRANBERRY necrosis, with hepatocyte nuclei diffusely enlarged and containing large basophilic inclusion bodies.Additionally, the heart exhibited a diffuse, moderate infiltration of lymphocytes and plasma cells, with focal thrombosis in the epicardium.
FAdV was detected in liver samples using specific primers Steamrollers for the hexon gene (52 K-fw and 52 K-rv) in a polymerase chain reaction (PCR) assay.Sequencing of the hypervariable region of this gene (Hex L1) for phylogenetic analysis revealed FAdV-D species serotype 11.To our knowledge, this is the first report of FAdV-D serotype 11 as the causative agent of a vertical outbreak of inclusion body hepatitis in broiler breeders in Brazil.