An investigation into the development of right displaced abomasum by rolling 268 dairy cows with left displaced abomasum

摘要

Right displaced abomasum (RDA) and abomasalvolvulus (AV) are common diseases in cattle. However,presently there is no consensus regarding the pathogenesisand nomenclature of the different positions thatthe abomasum can adopt in the right side of the cow.Therefore, the objective of this study was to describethe etiopathogenesis of the right displaced abomasumaccording to the description of the features observed in268 cows with left displaced abomasum (LDA), whichwere rolled to induce the movement of the abomasumfrom the left side to the right (in fact, inducing anRDA in 44% of cases), to facilitate the surgical approach,and immediately surgically treated (abomasalomentopexy from the right side). The observed RDApositions matched previously published descriptionsand names, and the authors propose a holistic andsimpler nomenclature and a clear hypothesis on RDAetiopathogenesis. In 54.1% of the cases, the abomasummoved to a normal position after rolling. The mostcommon RDA position observed was caudal displacementof the RDA (CdRDA; 70 out of 119 RDA cases;26.1% of the total number of cows), followed by lateraldisplacement (LRDA; 32 of 119; 11.9% of all cases),cranial displacement (CrRDA; 8 of 119; 3% of the total),medial displacement (MRDA; 4 of 119; 1.5% of thetotal), and finally, displacement lateral to the omasum(LORDA; 3 of 119; 1.1% of the total). Adverse eventsdirectly due to the rolling procedure were mesentericroot volvulus (3 of 268), cecocolic volvulus (2 of 268)and torsion (1 of 268), and uterus torsion (2 of 10 pregnantcows); 1 abortion (1 of 10 pregnant cows) was alsoobserved. We suggest that CdRDA is the first stage ofan RDA that can become an LRDA with increasingpressure. An LRDA can become an AV if rotating counterclockwise,viewed from above. An LDA, CdRDA, orLRDA could be initial forms of LORDA and CrRDA,and occur when forestomachs are empty or when theanimal stands up on its front legs first. The LORDAand CrRDA forms can lead to an omasum-abomasumvolvulus (OAV) or to a reticulum-omasum-abomasumvolvulus (ROAV) when pressure increases. With thisstudy we establish, for the first time, the sequence andincidence of each RDA form and its complications,increasing knowledge of this syndrome and its pathogenesis.This understanding critically aids the surgeon’sability to accurately assess and correct this disease andto predict prognosis.