One of 193 feeder pigs from a Midwest stockyard. Slight coughing was observed in the group. Three days later 123 gilts were sick with an influenza-like disease. The signs noted were coughing, anorexia, vomiting, shaking of the head, frequent getting up and down and convulsions. The next day, several were found dead and 20 others were sick. The findings at necropsy were edema and congestion of the lungs, pleural and pericardial effusion, epicardial petechiation, empty congested stomach, congestion of the intestine, liver, and spleen, and marked congestion of the meningeal vessels. Bacteriologic examination was negative.