Gouda Shaimaa M, Abdelaal Ahmed M, Gomaa Mohamed, Elgioushy Magdy M, Refaai Walid, Mouncey Rebecca R, Salem Shebl E
Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt.
Department of Surgery, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt.
J Adv Vet Anim Res. 2020 Apr 25;7(2):308-313. doi: 10.5455/javar.2020.g422. eCollection 2020 Jun.
Left displaced abomasum (LDA) is a common postparturient condition of high yielding dairy cattle. The diagnosis of LDA is challenging and has historically been based on findings that are not specific to the condition. The objective of the current study was to investigate the diagnostic performance of ultrasonography (USG) in the clinical management of dairy cows identified with left-sided ping sound .
Cows with reduced appetite and had audible left-sided ping sounds on abdominal auscultation were eligible to be prospectively recruited onto the study. The results of clinical findings and abdominal USG were recorded along with milk β-hydroxybutyrate levels, pH levels of abomaso/rumenocentesis samples, and findings on exploratory laparotomy. The diagnostic performance of USG and other clinical investigations was assessed by calculating the test sensitivity and specificity using exploratory laparotomy as a gold standard test.
A definitive diagnosis of LDA was made in 23 cows, 8 cows were diagnosed with peritonitis, and 4 cows with frothy tympany. The USG findings that were consistent with LDA were present in all cattle diagnosed with LDA at exploratory laparotomy. The USG findings over the past three intercostal space characteristics of LDA, however, were also present in five cases subsequently diagnosed with peritonitis and in all cases diagnosed with frothy tympany on exploratory laparotomy. The pH of abdomaso/rumenocentesis samples yielded the highest diagnostic accuracy (97.14%) as a single test in the current study.
USG over the left abdominal wall despite being a highly sensitive test for the diagnosis of LDA has limitations as a diagnostic tool due to suboptimal specificity.
左方变位真胃（LDA）是高产奶牛常见的产后病症。LDA的诊断具有挑战性，且历来基于并非该病症所特有的表现。本研究的目的是调查超声检查（USG）在确诊有左侧叩诊音的奶牛临床管理中的诊断性能。
食欲减退且腹部听诊可闻及左侧叩诊音的奶牛符合条件，被前瞻性纳入本研究。记录临床检查结果、腹部超声检查结果，以及牛奶β-羟丁酸水平、真胃/瘤胃穿刺样本的pH值和剖腹探查结果。以剖腹探查作为金标准试验，通过计算试验敏感性和特异性来评估USG及其他临床检查的诊断性能。
23头奶牛被确诊为LDA，8头奶牛被诊断为腹膜炎，4头奶牛被诊断为泡沫性鼓胀。在剖腹探查中被诊断为LDA的所有奶牛均出现了与LDA相符的超声检查结果。然而，在随后被诊断为腹膜炎的5例病例以及在剖腹探查中被诊断为泡沫性鼓胀的所有病例中，也出现了过去三个肋间间隙具有LDA特征的超声检查结果。在本研究中，作为单一检查，真胃/瘤胃穿刺样本的pH值诊断准确性最高（97.14%）。
尽管对左侧腹壁进行超声检查对LDA的诊断是一项高度敏感的检查，但由于特异性欠佳，作为诊断工具存在局限性。
