Torsion of the abomasum in ruminants: Diagrammatic representation of rotary movements based on post‐mortem findings

Summary

A theoretical analysis of the types of displacement of the abomasum in the abdomen is presented based on a stud of forty‐seven post‐mortem examinations of calves, cows, lambs and sheep showing right‐sided abomasal displacement and production of knots. These displacements are quantified following the introduction of a dual‐axial system. One system (XYZ) related to displacements of the abomasum on a pendulum model, the point of suspension being situated on the visceral surface of the liver and the arms consisting of parts of the digestive tract adjacent to the abomasum. The other system (x ₁ y ₁z₁ ) comprises axes centered on the abomasum, about which this organ was able to rotate without changing its position in the abdomen.

In order to make quantification of the displacements and deformations possible, the term twine is introduced. Twining results from interlacing of sections of the digestive tract, which are not normally adjacent. This limits the concept of torsion to helices appearing in the pyloro‐duodenal region and the omaso‐abomasal junction. To identify the various forms of abomasal displacement, a new terminology is introduced and basic elements suggested to make quantifications possible.     

One-step laparoscopic abomasopexy for correction of left-sided displacement of the abomasum in dairy cows

Four adult dairy cows in which a diagnosis of left-displaced abomasum (LDA) had been made underwent a 1-step laparoscopic abomasopexy (LA). The technique was performed with each cow positioned in dorsal recumbency. Two laparoscopic portals were created in the right paramedian area to identify the abomasum and direct insertion of the steel trocar and cannula into the abomasal lumen. A stainless steel toggle pin (with 2 lengths of suture attached to its midpoint) was inserted via the cannula into the abomasal lumen while the excess suture material remained exterior to the abdomen. The abomasum was deflated, and the excess suture material was withdrawn up to a preset marker on the suture to position the abomasum adjacent to the body wall. The suture was then tied to secure the abomasum in place. By use of this 1-step LA technique, LDA was successfully corrected in all 4 cows. The procedure is minimally invasive and allows viewing of the abomasum for correct positioning and fixation; it can be accomplished with the speed associated with the blind roll-and-tack technique. The 1-step LA technique may reduce the incidence of complications associated with traditional laparotomy and the blind roll-and-tack technique and could be a useful alternative procedure for the treatment of LDA in dairy cows.     

Ultrasonographic findings in cows with right displacement of the abomasum and abomasal volvulus

Seventeen cows with right displacement of the abomasum (rda) without abomasal volvulus, nine cows with abomasal volvulus and 10 clinically healthy cows were examined ultrasonographically. A 5.0 MHz transducer was used to scan the eighth to 12th intercostal spaces and the cranial and caudal aspects of the flank on the right side. The position, size and dorsal and ventral margins of the abomasum were determined at each imaging position. In both groups of diseased cows, the ventral abomasum contained fluid ingesta, which appeared hypoechogenic with diffuse echogenic stippling. The abomasal folds could be seen clearly as echogenic sickle-shaped structures within the ingesta. The dorsal abomasal gas cap varied in size and was characterised by reverberation artefacts, which appeared as echogenic lines running parallel to the body surface. Compared with the healthy cows, the abomasum was larger and located significantly closer to the midline of the dorsum in both groups of cows. Compared with the cows with rda, the abomasum in the cows with abomasal volvulus was significantly smaller in the eighth intercostal space and significantly larger in the 11th intercostal space. It was not possible to differentiate between rda and abomasal volvulus on the basis of the ultrasonographic findings.     

Left abomasal displacement and ulceration in an eight-week-old calf

Left displacement of the abomasum was diagnosed radiographically in an 8-week-old female Friesian calf. At surgery, a 4 cm ulcer was repaired and an abomasopexy performed during closure of the abdomen. Recovery from surgery was slow, and regurgitation of rumen contents occurred. Despite medical treatment, the calf died 4 days later. Left abomasal displacement is a well documented disease of dairy cattle (Robertson 1968; Coppock 1974; Martin et al 1978a; Poulsen 1976), but in young calves the condition is rare (Dirksen 1981). This report describes a case of left abomasal displacement with ulceration in an 8-week-old female Friesian calf.     

Ultrasonographic measurement of abomasal volume, location, and emptying rate in calves

OBJECTIVE: To develop and validate an ultrasonographic method for measuring abomasal volume, location, and emptying rate in suckling calves. ANIMALS: 9 male Holstein calves < 40 days of age. PROCEDURE: Before and after calves were fed different volumes of milk replacer or 2 L of oral electrolyte solutions, ultrasonographic measurements of abomasal dimensions (width, length, and height) were obtained by applying a 3.5-MHz sector probe to the ventral aspect of the abdomen in the transverse and sagittal planes. Abomasal volume was calculated from the ultrasonographic measurements by modeling the abomasum as an ellipsoid and by use of a power exponential equation to calculate the half-time of abomasal emptying (t1/2). RESULTS: Preprandial abomasal volume was 20 to 137 mL. All 3 abomasal dimensions increased during feeding and after suckling, and the abomasum was symmetrically located about the midline of the ventral aspect of the abdomen. Strong linear relationships were identified between ultrasonographic and suckled volumes, between ultrasonographic and scintigraphic heights, and between ultrasonographic and scintigraphic lengths. Ultrasonographic t1/2 was linearly related to scintigraphic t1/2; the latter is regarded as the gold standard measure of gastric emptying rate. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographic evaluation of the abomasum appears to provide a practical, rapid, noninvasive, and accurate method for determination of abomasal volume, location, and emptying rate in suckling calves.     

New aspects in the pathogenesis of abomasal displacement

Impaired abomasal motility and an increased accumulation of gas are prerequisites for displacement of the abomasum in the cow. Predisposing factors are the breed (e.g. Holstein-Friesian, Simmental-Red-Holstein cross breeds and Guernsey), genetic background, twin pregnancy, first weeks of lactation, metabolic disorders (ketosis, increased lipomobilisation, insulin resistance), high-concentrate and low-fibre diets, as well as other concomitant diseases, such as endometritis, mastitis and claw disorders. There does not appear to be a strong correlation between increased milk yield or endotoxaemia and abomasal displacement. Recent studies have focused on possible functional disorders of the enteric nervous system within the abomasal wall, since cattle with abomasal displacement have an increased activity of neuronal nitric oxide synthase, as well as decreased acetylcholine sensitivity. In addition, there appear to be significant differences between breeds in the levels of the neurotransmitters substance P (SP) and vasoactive intestinal peptide (VIP) in the abomasal wall. For example, SP (stimulatory) was significantly less in German Holsteins in comparison to the German Fleckvieh, whereas VIP (inhibitory) was markedly increased. These risk factors may explain why Holstein cows are more susceptible to abomasal displacement than other breeds.     

奶牛真胃变位的诊断与治疗

真胃变位(abomasal displacement)是指真胃正常解剖学位置发生改变,引起消化功能障碍,导致营养失调的消化系统疾病。真胃变位是奶牛常见疾病,多发于高产奶牛分娩前后,一般情况下多发生左方变位,在断奶前一般发生右方变位。该病主要造成奶牛的淘汰率增加,生产能力下降,治疗费用增多,给奶牛养殖业造成严重损失。本文介绍在富宁兰养殖场实习期间遇到的奶牛真胃变位病例,并从发病原因、临床症状、诊断、治疗、预防等几个方面进行总结,以期为有效防治奶牛真胃变位提供参考。     

Right displacement of the abomasum and abomasal volvulus in dairy cows: 458 cases (1980-1987)

Clinical and surgical findings in 458 dairy cows with right displacement of the abomasum or abomasal volvulus (AV) were analyzed to determine the association between these variables and the outcome (productive, salvaged, or terminal) of the affected cow. Heart rate at initial examination was higher in the salvaged and terminal groups of cows (P less than 0.0001) than in the productive group. The plasma Na+ concentration was lower in the salvaged and terminal groups of cows (P less than 0.0001) than in the productive group. The plasma C1- concentration was lower in the salvaged group of cows than in cows with either productive or terminal outcomes (P less than 0.0001). Anion gap was significantly higher (P less than 0.0001) in the salvaged and terminal groups than in cows classified as productive. On the basis of surgical findings, cattle with right displacement of the abomasum were more likely to survive than cows with AV. Cows that required fluid decompression of the abomasum via abomasotomy were less likely to survive than those in which gaseous decompression was performed. Cows with evidence of vascular compromise of the abomasal wall were less likely to survive than those with normal abomasal serosa. Preoperative heart rate and anion gap had positive correlations with the presence of abomasal necrosis, whereas temperature, venous blood pH, plasma bicarbonate, and base excess concentrations had negative correlations. Cows in terminal stages of AV were likely to have a mixed primary acid-base disturbance, consisting of metabolic alkalosis with superimposed metabolic acidosis. These findings were highly correlated with abomasal necrosis.     

Prognostic value of plasma L-lactate concentration measured cow-side with a portable clinical analyzer in Holstein dairy cattle with abomasal disorders

BACKGROUND: L-Lactate has been used as a prognostic indicator for ill humans and animals. A portable analyzer that measures L-lactate could help veterinarians decide to proceed with correction of a displaced abomasum. HYPOTHESES: The likelihood of a dairy cow with a displaced abomasum remaining in the herd can be predicted by lactate concentration and other variables. ANIMALS: Thirty-four healthy early-lactation dairy cows, and 131 cows with abomasal displacements (DA) presented to Cornell University, Ithaca, NY. METHODS: Plasma L-lactate was measured using a commercial analyzer (i-STAT). A cow had a positive outcome (PO) if she remained in the herd 30 days after surgical correction of the displaced abomasum and a negative outcome (NO) if she was culled or died in that time. A multivariable model with physical examination and clinicopathologic variables for predicting NO for cows with right-sided abomasal displacements was constructed. RESULTS: The median plasma L-lactate was 0.54 mM/L (interquartile range, 0.42-0.74) in healthy lactating Holstein cows. In cows with right-sided displaced abomasa, median plasma L-lactate concentrations were higher in cows with NO (5.88 mM/L) versus PO (3.23 mM/L) (P = .002). In a multivariable model, which identified chloride, heart rate, and L-lactate as the best fitting variables for cows with right-sided displacements, the probability of NO increased as L-lactate increased. CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma L-lactate concentration might be a useful predictor of productive outcomes in cows with right-sided abomasal disorders.     

Ultrasonographic assessment of change in abomasal position during the last three months of gestation and first three months of lactation in Holstein-Friesian cows

OBJECTIVE: To determine changes in abomasal position and dimensions during the last 3 months of gestation and first 3 months of lactation via transabdominal ultrasonography and determine whether surgical correction of left-displaced abomasum (LDA) by right flank omentopexy alters abomasal position within the abdomen in Holstein-Friesian cows. DESIGN: Observational study. ANIMALS: 20 heifers and 20 cows with no history of an LDA and 7 cows that had been treated for LDA via right flank omentopexy during an earlier lactation. Procedure-Ultrasonographic measurements were obtained 8 times during the last 3 months of gestation and first 3 months of lactation. Abomasal length, width, and volume were calculated from these measurements. RESULTS: The abomasum was always wider than it was long and located predominantly to the right of the midline. The presence of a right flank omentopexy had no effect on the measured parameters. Abomasal length decreased and width increased during the last 3 months of gestation, resulting in a more transverse orientation of the abomasum within the abdomen. These changes appeared to be in response to cranial expansion of the gravid uterus. The abomasum returned to a more caudal and right sagittal position within 14 days after parturition. CONCLUSIONS AND CLINICAL RELEVANCE: Abomasal dimensions, position, and volume change markedly during the last 3 months of gestation and first 3 months of lactation. Results permit detection of abnormal abomasal position in ill cows and indicate that the preferred location for abomasopexy is 20 cm caudal to the xiphoid process and 5 to 10 cm to the right of the ventral mid-line.     

Etiology and prophylaxis of reperfusion injuries]

In recent years the importance of oxyradicals in clinical veterinary medicine is incessantly grown. An important example in cattle breeding is the displaced abomasum in dairy cows. The antioxidative status of the animals is representable by means of the activity of superoxide dismutase (SOD) in the blood. Post operationem the activity of SOD decreased very fast. In cows with left abomasal displacement this activity increased within 24 hours to the starting level, but in cows with right abomasal displacement the SOD-activity in this period increased only insignificantly. Because of the low level of SOD-activity in blood serum the measuring should take place in erythrocyte lysate. Today there are many possibilities of therapeutical intervention of reperfusion injury, but their clinical efficiency has to be ascertained. The treatment of cows with displaced abomasum with ascorbate, tocopherole or prednisolone before the replacement of the abomasum shows first success in terms of the antioxidative and metabolic status.     

Cooperia pectinata and C. punctata, parasites of the abomasum of cattle in northern Cameroon (Central Africa)

Cooperia pectinata Ransom, 1907 and C. punctata von Linstow, 1907 are common trichostrongyles of zebu cattle in Africa. Their intestinal localization within the digestive tract is considered by many authors to be exclusive. Nevertheless, some limited surveys in Malagasy, Mauritania, The Gambia and Cameroon reported the presence of both Cooperia species in the abomasum. The present survey was carried out in a slaughterhouse of northern Cameroon on 17 zebu cattle and confirms the infection of the small intestine and the abomasum by the two species within the total number of cattle examined. Abomasal infections especially with Cooperia punctata were heavier than those in the intestine. Due to the movements of herdbreeders in Central Africa, and to the preliminary results obtained in Mauritania, The Gambia, Burkina Faso and Malagasy, abomasal localization of C. pectinata and C. punctata may be encountered in very large areas of Africa, and that cooperiosis may contribute together with Haemonchus species to the digestive disorders involving the abomasum.     

Ultrasonography of the omasum in cows with various gastrointestinal diseases

The omasums of 30 healthy cows and 55 cows with various gastrointestinal disorders (10 with left displacement and eight with right displacement of the abomasum, 10 with abomasal volvulus, 10 with traumatic reticuloperitonitis, nine with ileus of the small intestines and eight with reticulo-omasal stenosis) were examined ultrasonographically on the right side of the body with a 3.5 MHz linear transducer. The dorsal and ventral margins of the omasum and its size in the fifth to 11th intercostal spaces were determined. Generally, the ultrasonographic appearance of the omasum did not differ between the healthy and abnormal cows. The omasum appeared as a semicircle, and the omasal wall closest to the transducer was visible as a thick echogenic line. In a few of the abnormal cows, the omasal laminae were visible and the omasum appeared to have motility. In the cows with left and right displacement of the abomasum and abomasal volvulus, the dorsal margin of the omasum was significantly further from the dorsal midline in some intercostal spaces than in the healthy cows. In the cows with left displacement of the abomasum, the ventral margin of the omasum was significantly further from the dorsal midline in the 7th intercostal space than in the healthy cows. In the cows with reticulo-omasal stenosis, traumatic reticuloperitonitis and ileus of the small intestine, the ventral margin of the omasum was significantly closer to the dorsal midline in some intercostal spaces than in the healthy cows. The mean (sd) size of the omasum in the healthy cows varied from 16.3 (1.5) cm to 56.9 (10.0) cm, depending on the intercostal space, and the omasum was significantly smaller in some intercostal spaces in the cows with reticulo-omasal stenosis, right displacement of the omasum, abomasal volvulus and ileus of the small intestine.     

Cross-sectional study of the association of abomasal displacement or volvulus with serum electrolyte and mineral concentrations in dairy cows

The objective of this study was to evaluate serum mineral and electrolyte concentrations at the time of on-farm diagnosis of left displaced abomasum, right displaced abomasum, or abomasal volvulus in dairy cows. Data were collected from 104 affected cows and 96 control cows matched with cases, based on herd, parity, and stage of lactation. Cows with abomasal displacement or volvulus had significantly lower calcium, phosphorous, magnesium, potassium, and chloride concentrations and increased anion gap at the time of diagnosis compared with control cows from the same herds. The percentages of cases and controls with total serum calcium concentrations below the lower limit of the laboratory reference range (2.08 mmol/L [8.3 mg/dL]) were 70% and 23%, respectively. Based on the large percentage of cases with hypocalcemia, administering calcium salts at the time of treatment of field cases of abomasal displacement or volvulus may be beneficial.     

奶牛真胃变位发病原因研究进展

奶牛真胃变位的发病原因可能与真胃壁中肠道神经元功能性紊乱有关,这对揭示奶牛真胃变位的发病机制有重要意义.真胃变位奶牛肠道神经元的一氧化氮合酶活性升高,乙酰胆碱敏感性降低,真胃的运动力减弱和排空机能受损可能与这种异常关系有关,即抑制肠道神经元的增强活性,皱胃肌肉的胆碱能神经敏感性降低.流行病学调查和试验研究已证实真胃迟缓和真胃扩张是奶牛真胃变位的主要原因,同时,品种、遗传背景、双胎、泌乳早期阶段(特别是第1周)富含高精料日粮而缺乏优质粗饲料、代谢紊乱性疾病(酮病、脂肪动员增加、胰岛素抗药性)和其他并发疾病(子宫内膜炎、乳房炎、蹄病)等都是真胃变位发生的诱发因素.     

Influences on the occurrence of abomasal displacements in German Holstein cows]

The objectives of this study were to analyse risk factors for the prevalence of abomasal displacement in German Holstein cows. In the period from 02/01/1999 to 01/31/2000 five veterinary surgeons in Northern Lower Saxony registered all cases of abomasal displacement in German Holstein cows being under the official milk recording scheme. In total, the investigation included 160 farms and 9315 cows. An abomasal displacement was registered in 151 German Holstein cows, corresponding to a frequency of 1.6%. More than 75% of the abomasal displacements appeared during the first 30 days after calving. The left abomasal displacement (74.8%) was recorded more often than the right abomasal displacement (25.2%). Milk recording and pedigree data were supplied by the VIT (Vereinigte Informationssystem Tierhaltung), Verden, and merged with the own recordings. The influences of the calving month, the lactation number, the age at calving, the inbreeding coefficient, calving performance, duration of pregnancy, breed of calf sire, calf sire and the breeding values for the milk performance did not explain a significant part of the variation of the frequency of the abomasal displacement. Significant effects of the sire, birth of twins or even more calves and the herd were obtained for the leftsided abomasal displacement. For the rightsided abomasal displacement and for all abomasal displacements the herd effect was not significant. Heritability estimates using bivariate linear REML models were h2 = 0.043 +/- 0.012 for the leftsided abomasal displacement, and h2 = 0.007 +/- 0.004 for the rightsided abomasal displacement, respectively. Using the threshold model the heritabilities yielded estimates of h2 = 0.51 for the left abomasal displacement, and for the right abomasal displacement of h2 = 0.19, respectively.     

Effect of cimetidine on abomasal pH and Haemonchus and Ostertagia species in sheep

Cimetidine, a histamine H2-receptor blocking agent which reduces gastric acid flow in simple stomach animals was administered directly into the abomasum of sheep at 100 mg kg-1 twice daily for five consecutive days and again on the eighth day. The drug caused a significant increase in the pH values of the abomasal contents and was highly effective in reducing the adult population of Haemonchus contortus (100 per cent) and Ostertagia circumcincta (70 per cent) in the abomasum of sheep. The possibility of using cimetidine as a method of treating abomasal nematode parasitism is discussed.     

Right flank laparotomy and abomasotomy for removal of a phytobezoar in a standing cow

A 4.5-year-old Holstein-Friesian cow underwent surgery because of left abomasal displacement. Intra-operative palpation of the pyloric region revealed a phytobezoar. The abomasum containing the phytobezoar was exteriorized, and an incision was made directly over the mass in the region of the greater curvature of the pyloric part of the abomasum.