The objectives of this study were to determine the etiology and types of vagal indigestion (VI) occurring after right displacement of the abomasum or abomasal volvulus (RDA/AV), and the prognosis for each type. Data of cows presented for RDA/AV from a retrospective (n = 288) and a prospective (n = 132) study were used. Vagal indigestion occurred in 39 and 22 cows in each study, respectively. A necropsy was performed in 29 cases. Gastric compartment dilation compatible with VI type III or IV occurred in 23 cases. An abnormal gastric wall was detected in 22 cases. Peritonitis was present in 18 cows. Vagal nerve lesions were present in 5 out of 13 cases studied. Clinical, hematological, and necropsy results suggested a classification of VI with respect to presence or absence of peritonitis. Gastric wall damage, peritonitis and vagal nerve lesions appear important in the etiology. Considering peritonitis occurrence, antimicrobial therapy appears necessary in the treatment of RDA/AV.