Thirteen 125-day-old pullets were inoculated intramuscularly with 4.8×10⁸colony forming units of an “Actinobacillussalpingitidis”/avianPasteurellahaemolytica-like isolate. Most of the inoculated birds showed. no clinical signs. In one of 6 cases sacrificed at 13 days postinoculation, the pericardium, was found to be severely thickened and adhered to the epicardium, and ruptured egg yolks were observed in the abdominal cavity in 4 of 7 cases sacrificed at 44 days postinoculation. Histopathology revealed pericarditis and heterophil infiltration in Glisson's sheath of the liver and theca of ovarian follicle. The organism was recovered from the brain, lung, heart, liver, kidney, ovary and oviduct of some cases.