EVALUATION OF THE PATHOGENESIS OF VAGUS INDIGESTION IN COWS WITH TRAUMATIC RETICULOPERITONITIS

Objective-To evaluate the functional importance of impaired reticular contractions attributable to inflammatory adhesions in the pathogenesi s of vagus indigestion in cows with traumatic reticuloperitonitis (TRP ). Design-Case control study. Animals-42 dairy cows with TRP were comp ared with 10 healthy control cows. Cows with TRP were assigned to 3 gr oups: cows with uncomplicated TRP (n = 15), cows with TRP and a distur bance of digesta passage through the reticular-omasal orifice (TRP-AD; n = 17), and cows with TRP and a disturbance of digesta passage throu gh the pylorus (TRP-PD; n = 10). Procedure-Cows were evaluated, using routine clinical methods, biochemical analysis of blood and ruminal fl uid samples, exploratory rumenotomy, and postmortem examination. Resul ts-Damage of thoracic and abdominal parts of the main vagal branches w ere not evident in cows with TRP. Parareticular inflammatory adhesions were more extensive in cows with TRP-AD and in cows with TRP-PD than in cows with uncomplicated TAP. Reticular motility was decreased in co ws with TRP-AD and TRP-PD, compared with cows with uncomplicated TRP a nd control cows. In contrast to cows with uncomplicated TRP and cows w ith TRP-AD, the abomasum was impacted with large amounts of long fibro us material in most of the cows with TRP-PD. Clinical Implications-We believe that disturbances of digesta passage in cows with TRP represen t distinct stages of a common pathogenetic course. The primary disease mechanism was a disturbance in particle-separating processes in the r eticulum/rumen attributable to mechanical inhibition of reticular moti lity that was the result of extensive inflammatory parareticular adhes ions.