Surgery of the bovine abomasum

Milk Yield, Hematological and Electrolyte Parameters in Primiparous Dairy Cows After Laparotomic Omentopexy and One-Step Laparoscopic Abomasopexy Treatments of Left Displaced Abomasum

This study aimed to evaluate the effects of two different treatment options for the correction of left displaced abomasum (LDA) on milk yield, hematological, electrolyte parameters, lactate and cortisol concentrations in primiparous cows. Twenty four Holstein cows were randomly assigned into three groups: cows treated with one-step laparoscopic abomasopexy (LPS, n=8), cows treated by left paralumbar omentopexy (LPT, n=8) and healthy cows (CON, n=8), matched by parity and days in milk. Blood samples were collected before (D0) and after (D0’) surgery, and 1 (D1), 3 (D3), 10 (D3) and 30 (D30) days following surgery. LPS and LPT cows at D0 as well as LPT cows at 30 d following surgery had lower milk yield than CON cows (P<0.05), while the service period was higher in LPT than in CON (P<0.05). WBC was lower at D0 as well as Hb and Ht at D0 and D0’ in CON group than those of LPS and LPT (P<0.05). Hyponatremia, hypochloremia and hypokalemia at D0 and D0’ were observed in LPS and LPT. In addition, LPT cows had lower Na and Cl at D1 and D3 and lower K at D1 than CON (P<0.05). Impaired hydration in LPS and LPT cows was accompanied by higher concentrations of lactate at D0, D0’, D1 and D3 (P<0.01) and cortisol at D0 and D0’ (P<0.01) compared with CON group, while LPT had higher cortisol at D0’ than LPS (P<0.05). These results indicated that LPS has the potential to improve the convalescence period of LDA in primiparous cows.

Treatments and outcomes of severe hemorrhagic enteritis in three eastern bongos (Tragelpahus eurycerus isaacii) at the Singapore Zoo

Three eastern bongos (Tragelaphus eurycerus isaaci) presented acutely with hemorrhagic diarrhea at the Singapore Zoo, thought to be caused by a mouldy batch of hay. Repeated fecal tests were negative of parasites and common gastrointestinal bacteria including salmonella and campylobacter. The diarrhea resolved for all individuals after a week of leaf-only diet. However, 2 individuals developed signs of colic. Both animals were anesthetized for examination including blood tests and imaging studies. The findings were consistent of gastrointestinal ileus and a possible impaction. With intensive treatment involving repeated sedations for fluid therapy administration and treatments for gastrointestinal impaction, one individual eventually made a full recovery, but the other individual died due to septic peritonitis secondary to a rupture in the spiral colon. Persistent supportive therapy may be vital in treating severe gastrointestinal disease in this species.

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

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.

IMAGING DIAGNOSIS-TRAUMATIC ABOMASITIS CAUSED BY FOREIGN BODIES IN A COW

A 2-year-old Holstein cow presented with a history of colic signs of 3 days' duration that had not responded to routine medical therapy. Physical examination findings were consistent with tachycardia and colic. Ultrasonographic examination of the abomasum revealed a thin hyperechoic line producing a cone shadow. Radiography of the cranial abdomen revealed two radiopaque objects within the abomasum. Right paracostal laparotomy and abomasotomy permitted palpation and manual removal of two metallic foreign bodies and a small quantity of gravel. The animal recovered well after surgery and no signs of colic were observed. Her appetite and rumination were also improved.

Preoperative cow-side lactatemia measurement predicts negative outcome in Holstein dairy cattle with right abomasal disorders

The objectives of the current study were (1) to determine the gain in prognostic accuracy of preoperative l-lactate concentration (LAC) measured on farm on cows with right displaced abomasum (RDA) or abomasal volvulus (AV) for predicting negative outcome; and (2) to suggest clinically relevant thresholds for such use. A cohort of 102 cows with on-farm surgical diagnostic of RDA or AV was obtained from June 2009 through December 2011. Blood was drawn from coccygeal vessels before surgery and plasma LAC was immediately measured by using a portable clinical analyzer. Dairy producers were interviewed by phone 30 d following surgery and the outcome was determined: a positive outcome if the owner was satisfied of the overall evolution 30 d postoperatively, and a negative outcome if the cow was culled, died, or if the owner reported being unsatisfied 30 d postoperatively. The area under the curve of the receiver operating characteristic curve for LAC was 0.92 and was significantly greater than the area under the curve of the receiver operating characteristic curve of heart rate (HR; 0.77), indicating that LAC, in general, performed better than HR to predict a negative outcome. Furthermore, the ability to predict a negative outcome was significantly improved when LAC measurement was considered in addition to the already available HR data (area under the curve: 0.93 and 95% confidence interval: 0.87, 0.99). Important inflection points of the misclassification cost term function were noted at thresholds of 2 and 6 mmol/L, suggesting the potential utility of these cut-points. The 2 and 6 mmol/L thresholds had a sensitivity, specificity, positive predictive value, and negative predictive value for predicting a negative outcome of 76.2, 82.7, 53.3, and 93.1%, and of 28.6, 97.5, 75, and 84%, respectively. In terms of clinical interpretation, LAC ≤2 mmol/L appeared to be a good indicator of positive outcome and could be used to support a surgical treatment decision. The treatment decision for cows with LAC between 2 and 6 mmol/L, however, would depend on the economic context and the owner's attitude to risk in regard to potential return on its investment. Finally, performing a surgical correction on commercial cows with RDA or AV and a LAC ≥6 mmol/L appeared to be unjustified and these animals should be culled based on their high probability of negative outcome.

Minimally invasive field abomasopexy techniques for correction and fixation of left displacement of the abomasum in dairy cows

To reduce the potential drawbacks associated with laparotomy techniques for correction and fixation of left displaced abomasums (LDA), minimally invasive techniques have been developed. This chapter reviews the toggle pin suture (TPS) and the laparoscopic abomasopexy procedures used in the field for correction and fixation of the abomasum for correction of left-displacement of the abomasum in dairy cows. The importance of case selection cannot be overestimated. By combining laparoscopy with the principle of the TPS procedure, the lack of visual control associated with the TPS procedure is eliminated, while the advantage of the speed of completion and minimal invasiveness provided by both procedures are maintained. Successful LDA treatment includes not only early detection and treatment of the LDA, but also the prevention of secondary ketosis and aggressive treatment of concurrent disease.

Ischaemia/reperfusion injury in experimentally induced abomasal volvulus in sheep

The purpose of the study was to evaluate ischaemia/reperfusion injury in simulated abomasal volvulus in sheep. Sixteen ewes were randomly allocated to three groups. The control group (n=4) served as sham-operated controls. The animals of the ischaemia group and reperfusion group (n=6, each) underwent a simulated 'abomasal volvulus'. The abomasum was exteriorized under general inhalation anesthesia and forced into a 180( composite function) anticlockwise rotation around its longitudinal axis, followed by another 270( composite function) anticlockwise rotation around its transectional axis. All ewes were monitored for 4 h. In the reperfusion group, volvulus was released after 3 h (i.e., 1 h of reperfusion). In the ischaemia group, the volvulus remained for 4 h (no reperfusion). Vital signs were monitored and some haematological and biochemical parameters were measured, without any significant differences. Full-section biopsy specimens were taken at the 3rd and 4th hours from the greater curvature of the abomasum. Histopathological lesions were scored according to the severity of mucosal oedema, submucosal oedema, haemorrhage submucosal and submuscularis layers, and polymorphonuclear infiltration on a scale of 0 to 4 (nil, mild, moderate, severe, and extreme). Another biopsy specimen was taken at the 4th hour for transmission electron microscopic examination. The scored lesions in light-microscopic examination were significantly different at the 3rd and 4th hours between the control and the experimental groups (p<0.05). There was no significant difference between the reperfusion and ischaemia groups (p>0.1). Within-group comparisons (3rd hour with 4th hour) revealed no significant differences. In transmission electron microscopic examination there were no remarkable changes in the control group, but in the ischaemia and reperfusion groups there were remarkable cellular (epithelial and goblet cells), mitochondrial and microvillous changes that strongly implied the occurrence of ischaemia (p<0.05). In transmission electron-microscopic examination of abomasal samples the lesions were more remarkable in reperfusion group than in the ischaemia group. It is concluded that ischaemia/reperfusion injury occurred in this model of simulated abomasal volvulus in sheep and that ischaemia/reperfusion injury should be considered as a potential determining factor in the outcome of cattle with abomasal volvulus.

Distribution of muscarinic receptor subtypes and interstitial cells of Cajal in the gastrointestinal tract of healthy dairy cows

OBJECTIVE

To describe the distribution of muscarinic receptor subtypes M(1) to M(5) and interstitial cells of Cajal (ICCs) in the gastrointestinal tract of healthy dairy cows.

SAMPLE POPULATION

Full-thickness samples were collected from the fundus, corpus, and pyloric part of the abomasum and from the duodenum, ileum, cecum, proximal loop of the ascending colon, and both external loops of the spiral colon of 5 healthy dairy cows after slaughter.

PROCEDURES

Samples were fixed in paraformaldehyde and embedded in paraffin. Muscarinic receptor subtypes and ICCs were identified by immunohistochemical analysis.

RESULTS

Staining for M(1) receptors was found in the submucosal plexus and myenteric plexus. Antibodies against M(2) receptors stained nuclei of smooth muscle cells only. Evidence of M(3) receptors was found in the lamina propria, in intramuscular neuronal terminals, on intermuscular nerve fibers, and on myocytes of microvessels. There was no staining for M(4) receptors. Staining for M(5) receptors was evident in the myocytes of microvessels and in smooth muscle cells. The ICCs were detected in the myenteric plexus and within smooth muscle layers. Distribution among locations of the bovine gastrointestinal tract did not differ for muscarinic receptor subtypes or ICCs.

CONCLUSIONS AND CLINICAL RELEVANCE

The broad distribution of M(1), M(3), M(5), and ICCs in the bovine gastrointestinal tract indicated that these components are likely to play an important role in the regulation of gastrointestinal tract motility in healthy dairy cows. Muscarinic receptors and ICCs may be implicated in the pathogenesis of motility disorders, such as abomasal displacement and cecal dilatation-dislocation.

Ventral laparoscopic abomasopexy in 18 cattle with displaced abomasum

OBJECTIVE

To evaluate the feasibility and outcome of a technique for laparoscopic abomasopexy in cattle with displaced abomasum (DA).

STUDY DESIGN

Retrospective study.

ANIMALS

Dairy cattle (n=18).

METHODS

Retrieved data included signalment, clinical findings, treatments, and outcome. Laparoscopic abomasopexy was performed with the sedated cow in dorsal recumbency. The pexy site was determined after identification of the antrum and the greater curvature of the abomasum. Three or 4 absorbable sutures were passed through the body wall and abomasal wall for abomasal fixation. Wound complications, DA recurrence, food consumption, owner satisfaction, and long-term survival were assessed.

RESULTS

Left DA was diagnosed in 17 cows and right DA in 1 cow. Abomasal decompression was performed in 12 cows and abomasopexy was achieved in all cows. Surgical wounds healed without complication, except in 4 cows that had mild periportal swelling. Postoperative return to normal appetite occurred quickly except for 2 cows with concurrent diseases. Owner satisfaction varied from good to excellent. DA did not recur.

CONCLUSION

Ventral laparoscopic abomasopexy was successfully performed in 18 cows with DA. Abomasal decompression was necessary for adequate abomasal manipulation and identification of landmarks for pexy. An adequate return to food consumption and no recurrence of DA occurred (mean follow-up, 15.5 months).

CLINICAL RELEVANCE

Ventral laparoscopic abomasopexy is technically feasible and an effective method for surgical treatment of DA.

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.

Feed intake, milk yield, and metabolic parameters prior to left displaced abomasum in dairy cows

As left-displaced abomasum (LDA) often occurs in cows with high contents of fat in the liver (fatty liver), a postpartum fatty liver-inducing regimen was applied to 16 cows. The main interest of the study was whether there were productive or metabolic changes in cows prior to LDA. Therefore, feed intake and milk production were monitored and blood samples were collected from the cows. The LDA occurred in 4 out of 16 dairy cows that were included in the feeding regimen. Compared to cows not developing LDA, LDA-cows had a significantly lower feed intake, 6.5 kg/d less, and milk production, 8 kg/d less, prior to clinical diagnosis of LDA. In the 10-d period preceding clinical diagnosis of LDA, blood concentrations of calcium, glucose, and insulin were significantly lower, whereas blood concentrations of nonesterified fatty acids and beta-hydroxybutyrate, as well as aspartate aminotransferase activities were significantly elevated compared to cows not developing LDA. These preclinical changes may play an important role in the pathogenesis of LDA. It is not certain, however, whether there is a causal association between these parameters and LDA.

Spontaneous in vitro contractile activity of specimens from the abomasal wall of healthy cows and comparison among dairy breeds

OBJECTIVE

To characterize and compare in vitro contractility patterns of sections of abomasal wall harvested from cattle of 3 dairy breeds.

SAMPLE POPULATION

Longitudinal and circular smooth muscle preparations harvested from the antrum and body of the abomasum of 30 recently slaughtered Holstein-Friesian, Brown Swiss, and Simmental X Red Holstein cows.

PROCEDURE

Spontaneous isometric contractions of specimens in tissue baths of modified Krebs solution were recorded during a 4-hour period. Maximal amplitude, frequency of contractions, and change of basal tension were used to characterize contractility. Statistical analyses were used to test for differences among time periods, among breeds, between specimen locations, and between fiber orientations.

RESULTS

Myoactivity patterns of abomasal smooth muscle preparations are highly variable and differ on the basis of location and fiber orientation. Frequency of contractions differed significantly among time periods for longitudinally oriented specimens with decreasing frequencies of contractions over time. Maximal amplitude of the longitudinally oriented specimens from the antrum increased significantly, whereas maximal amplitude of the circularly oriented specimens from the antrum decreased significantly. Values did not differ significantly among breeds.

CONCLUSIONS AND CLINICAL RELEVANCE

Patterns of spontaneous contractility of abomasal wall specimens are not homogeneous. During a 4-hour recording period, maximal amplitude and frequency of contractions of specimens varied significantly with respect to orientation and location; however, spontaneous contractile myoactivity did not differ significantly among breeds. Therefore, breed predisposition for displaced abomasum is not correlated with spontaneous activity of smooth muscle specimens.

Drugs coordinating and restoring gastrointestinal motility and their effect on selected hypodynamic gastrointestinal disorders in horses and cattle

Hypodynamic gastrointestinal disorders in horses and cattle that are thought to benefit from treatment with drugs restoring and coordinating gastrointestinal motility include postoperative ileus and large colon impaction in the horse and displacement of the abomasum and dilatation of the cecum in cattle. Important physiologic, pathophysiologic and pharmacologic mechanisms involved in the intrinsic control of gastrointestinal motility include cholinergic, adrenergic, dopaminergic, serotoninergic, and opioid-mediated pathways. Preliminary results suggest that cisapride, acting on 5-Hydroxytryptamine receptors, might be useful for treatment of idiopathic postoperative ileus and the alpha 2-adrenoceptor blocking agent yohimbine for endotoxic postoperative ileus. Naloxone, an opioid antagonist, and neostigmine, an acetylcholinesterase inhibitor, are thought to restore motility of the large colon in cases of large colon impaction in the horse. Bethanechol and neostigmine significantly increase myoelectric activity of the cecum and proximal loop of the ascending colon in healthy cows. Investigations of the effects of prokinetic drugs on displacement of the abomasum of cattle do not allow any conclusions because no results derived from controlled experimental disease models are available.