Abstract
An outbreak of esophagectasis associated with transit impairment of food through the cardia was observed in F344 rats used in 12 long-term dietary studies. Symptoms initiated with slight influenza like signs lasting largely more than 10 weeks, and progressed to frequent sneezing with eruption of food and marked emaciation. An attempt to insert a stomach tube was rejected to pass through the cardiac ostium. Bacteriological and immunological checks for causative agents of pneumonia were negative. At autopsy, markedly dilated esophagus with pulpified powdered chow, and atelectatic areas on the lung were prominently observed. No histological abnormalities corresponding to the symptoms were demonstrated by ordinary light microscopic examinations in the peripheral nerve as well as central nervous system, although suppurative or foreign body pneumonia, otitis media and rhinitis were frequently seen. Females were more vulnerable to the disease than males. Morbidity of the disease varied between each lot of the animals of both sexes. In the highest case 23 out of 50 females died of the disease. The majority of the disease occurred in the animals older than 70 weeks of age.
