Department of Animal Medicine and Surgery, Universidad Complutense de Madrid (UCM), 28040 Spain; Trialvet Veterinary Consultancy and Research SL, 28721 Madrid, Spain.
Department of Animal Medicine and Surgery, Universidad Complutense de Madrid (UCM), 28040 Spain; Faculty of Biomedical Sciences, Universidad Europea de Madrid, 28670 Spain.
J Dairy Sci. 2019 Dec;102(12):11268-11279. doi: 10.3168/jds.2019-16529. Epub 2019 Sep 20.
Right displaced abomasum (RDA) and abomasal volvulus (AV) are common diseases in cattle. However, presently there is no consensus regarding the pathogenesis and nomenclature of the different positions that the abomasum can adopt in the right side of the cow. Therefore, the objective of this study was to describe the etiopathogenesis of the right displaced abomasum according to the description of the features observed in 268 cows with left displaced abomasum (LDA), which were rolled to induce the movement of the abomasum from the left side to the right (in fact, inducing an RDA in 44% of cases), to facilitate the surgical approach, and immediately surgically treated (abomasal omentopexy from the right side). The observed RDA positions matched previously published descriptions and names, and the authors propose a holistic and simpler nomenclature and a clear hypothesis on RDA etiopathogenesis. In 54.1% of the cases, the abomasum moved to a normal position after rolling. The most common RDA position observed was caudal displacement of the RDA (CdRDA; 70 out of 119 RDA cases; 26.1% of the total number of cows), followed by lateral displacement (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 the total), and finally, displacement lateral to the omasum (LORDA; 3 of 119; 1.1% of the total). Adverse events directly due to the rolling procedure were mesenteric root volvulus (3 of 268), cecocolic volvulus (2 of 268) and torsion (1 of 268), and uterus torsion (2 of 10 pregnant cows); 1 abortion (1 of 10 pregnant cows) was also observed. We suggest that CdRDA is the first stage of an RDA that can become an LRDA with increasing pressure. An LRDA can become an AV if rotating counterclockwise, viewed from above. An LDA, CdRDA, or LRDA could be initial forms of LORDA and CrRDA, and occur when forestomachs are empty or when the animal stands up on its front legs first. The LORDA and CrRDA forms can lead to an omasum-abomasum volvulus (OAV) or to a reticulum-omasum-abomasum volvulus (ROAV) when pressure increases. With this study we establish, for the first time, the sequence and incidence of each RDA form and its complications, increasing knowledge of this syndrome and its pathogenesis. This understanding critically aids the surgeon's ability to accurately assess and correct this disease and to predict prognosis.
右方变位真胃（RDA）和真胃扭转（AV）是牛的常见疾病。然而，目前对于真胃在牛右侧可以采取的不同位置的发病机制和命名尚无共识。因此，本研究的目的是根据 268 头左侧变位真胃（LDA）牛的滚动诱导真胃从左侧移动到右侧（实际上在 44%的情况下诱导 RDA）的特征描述，来描述 RDA 的发病机制，以方便手术入路，并立即进行手术治疗（从右侧进行真胃大网膜固定术）。观察到的 RDA 位置与先前发表的描述和名称相匹配，作者提出了一个整体和更简单的命名法，并对 RDA 的发病机制提出了一个明确的假说。在 54.1%的情况下，滚动后真胃恢复到正常位置。观察到的最常见的 RDA 位置是 RDA 的尾部移位（CdRDA；119 例 RDA 中的 70 例；所有牛的 26.1%），其次是外侧移位（LRDA；119 例中的 32 例；所有病例的 11.9%），头部移位（CrRDA；119 例中的 8 例；总病例的 3%），内侧移位（MRDA；119 例中的 4 例；总病例的 1.5%），最后是真胃外侧移位（LORDA；119 例中的 3 例；总病例的 1.1%）。直接归因于滚动程序的不良事件有肠系膜根部扭转（268 例中的 3 例）、盲肠结肠扭转（268 例中的 2 例）和扭转（268 例中的 1 例），以及子宫扭转（10 头妊娠牛中的 2 例）；还观察到 1 例流产（10 头妊娠牛中的 1 例）。我们建议 CdRDA 是 RDA 的第一阶段，随着压力的增加，它可以成为 LRDA。如果从上方观察到逆时针旋转，LRDA 可以成为 AV。LDA、CdRDA 或 LRDA 可能是 LORDA 和 CrRDA 的初始形式，当瘤胃空瘪或动物首先用前腿站立时发生。LORDA 和 CrRDA 形式会导致真胃-网胃-瓣胃扭转（OAV）或网胃-瓣胃-真胃扭转（ROAV），当压力增加时。通过本研究，我们首次确定了每种 RDA 形式及其并发症的顺序和发生率，增加了对这种综合征及其发病机制的认识。这种理解极大地帮助了外科医生准确评估和纠正这种疾病，并预测预后的能力。
