Comparison of abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with left displaced abomasum or abomasal volvulus

OBJECTIVE: To compare abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with a left displaced abomasum (LDA) or abomasal volvulus (AV). ANIMALS: 40 lactating dairy cows (25 with an LDA and 15 with an AV). PROCEDURE: Abomasal luminal gas pressure and volume and pulse oximetry values for the caudal portion of the dorsal ruminal sac and abomasal wall were measured during laparotomy. Abomasal perfusion was assessed on the basis of abomasal O2 saturation (pulse oximetry) before correction of the LDA or AV. Abomasal perfusion was also assessed after correction of the LDA or AV by measuring venous O2 saturation in the right gastroepiploic vein and calculating the abomasal oxygen-extraction ratio. RESULTS: Abomasal luminal gas pressure and volume were higher in cattle with an AV than in cattle with an LDA. Abomasal O2 saturation was lower and abomasal oxygen-extraction ratio higher in cattle with an AV, compared with values in cattle with an LDA. In cows with an AV, lactate concentration in the gastroepiploic vein was greater than that in a jugular vein, whereas no difference in lactate concentrations was detected in cows with an LDA. Abomasal luminal gas pressure was positively correlated (r, 0.51) with plasma lactate concentration in the gastroepiploic vein and negatively correlated (r, -0.32) with abomasal O2 saturation determined by use of pulse oximetry. CONCLUSIONS AND CLINICAL RELEVANCE: Abomasal perfusion decreases as luminal pressure increases in cattle with an AV or LDA.     

Peritoneal fluid analysis in dairy cows with left displaced abomasum and abomasal volvulus

Peritoneal fluid (PF) was evaluated in 40 cows with left displaced abomasum (LDA) and 15 cows with abomasal volvulus (AV). PF was obtained by abdominocentesis at the right ventral abdomen at admission. Simultaneously, a blood sample was taken from the jugular vein. Biochemical and cytological variables in blood and PF specific for ischaemia, inflammation and cell damage were compared. Total protein, albumin, glucose and cholesterol were normal in PF of cows with LDA and AV. Although L-lactate increased in both groups, cows with AV had significantly higher values (LDA: 1.47/0.69/2.68 mmol/l; AV: 6.45/4.55/12.89 mmol/l (median/1. quartile/3. quartile)). D-dimer (LDA: 0.50/0.22/0.88 mg/l; AV: 1.11/0.40/1.85 mg/l) and LDH (LDA: 663/437/943 U/l; AV: 1099/750/1439 U/l) were only increased in PF of cows with AV. The number of leucocytes was normal; however, significantly more peritoneal neutrophils appeared necrotic or apoptotic after AV. PF of cows with abomasal displacement showed distinctive features of ischaemia and inflammation. Characteristics of haemostatic dysfunction and cell damage were mainly evident in PF of cows with AV. The results suggest that anti-inflammatory therapy is indicated in each cow with abomasal displacement. Additionally, medical treatment should be directed to prevent complications of ischaemia and reperfusion in cows with AV.     

Prevalence of endotoxemia in healthy postparturient dairy cows and cows with abomasal volvulus or left displaced abomasum

Left displaced abomasum (LDA) and abomasal volvulus (AV) occur most commonly in postparturient dairy cows. Our main hypothesis was that endotoxemia occurred more frequently in the peripheral blood of cows with LDA or AV than in healthy cows because increased luminal pressure in AV or LDA, or the presence of a hemorrhagic strangulating obstruction in AV, may have injured the abomasal mucosa, thereby facilitating translocation of luminal endotoxin into the circulation. Therefore, our main objective was to compare the prevalence and magnitude of endotoxemia in healthy postparturient cows with the prevalence and magnitude of endotoxemia in cows with AV and LDA. We examined 60 adult dairy cows in early lactation that were diagnosed with AV (n = 15) or LDA (n = 15) or were healthy on physical examination (control group, n = 30). Jugular venous blood was obtained from cows in all 3 groups, and right gastroepiploic venous blood was obtained during surgical correction of AV and LDA immediately after repositioning of the abomasum. Platelet-rich plasma endotoxin concentrations were measured with a chromogenic limulus amoebocyte lysate assay. Endotoxin was detected in jugular vein plasma in 50% (15/30) of control cows; however, the prevalence of endotoxemia was significantly lower (P < .05) in cows with AV (7%, 1/15) or LDA (20%, 3/15). Endotoxin was detected simultaneously in right gastroepiploic and jugular vein plasma in only 1 cow with LDA and 0 cows with AV. Contrary to our hypothesis, we conclude that endotoxemia is infrequently present in postparturient dairy cows with AV or LDA.     

Use of the D-xylose absorption test to measure abomasal emptying rate in healthy lactating Holstein-Friesian cows and in cows with left displaced abomasum or abomasal volvulus

We determined the abomasal emptying rates of Holstein-Friesian cows at different stages of lactation, with left displaced abomasum (LDA), or immediately after surgical correction of LDA or abomasal volvulus (AV). D-xylose (0.5 g/kg body weight [BW], 50% solution) was injected into the abomasum in healthy cows (group 1, 4-7 days in milk [DIM], n = 7; group 2, 90-120 DIM, n = 7; group 3, > 300 DIM, n = 7) and in cows with LDA (n = 10; group 4). D-xylose was injected into the abomasum during right flank laparotomy in cows with LDA (n = 22; group 5) and cows with AV (n = 15; group 6). The time to maximal serum D-xylose concentration was used as an index of emptying rate. The abomasal emptying rates for cows in groups 1, 2, and 3 were similar, whereas emptying was slower in cows with LDA and in cows after surgical correction of LDA or AV. The abomasal emptying rate of cows with LDA was slowed to a greater extent immediately after surgery, when compared to the rate obtained before surgery. There was no difference in abomasal emptying rate immediately after surgical correction between cows with LDA or AV. The results indicate that the increased incidence of LDA in the first month of lactation is not associated with an intrinsic decrease in abomasal emptying rate in healthy cows. Our findings also demonstrate that surgical correction further slows the emptying rate in cows with LDA.     

Risk factors for abomasal volvulus and left abomasal displacement in cattle.

A hospital-based case-control study was conducted to evaluate and compare risk factors for abomasal volvulus (AV) and left displaced abomasum (LDA) in cattle. Medical record abstracts were derived from 17 North American veterinary schools by the Veterinary Medical Data Program for all cattle admitted between Jan 1, 1977 and Dec 31, 1986, and for those with a diagnosis of AV or LDA. From a total of 108,956 individual cattle records, 1,036 cases of AV and 7,695 cases of LDA were identified, with a ratio of LDA to AV cases of 7.4 to 1. In-hospital mortality was 23.5% for AV and 5.6% for LDA. Age, breed, gender, and season each had significant (P less than 0.05) effects on risk for AV and LDA. Risk for AV and LDA increased with increasing age, with greater risk in cattle aged 4 to 7 years. Dairy cattle were at higher risk of developing AV (adjusted odds ratio, 36.4) and LDA (adjusted odds ratio, 95.2) than were beef cattle. The odds of AV in Brown Swiss cattle were significantly (P less than 0.0001) lower, and the odds of LDA in Guernsey cattle were significantly (P less than 0.0001) higher than those in Holstein cattle. Female cattle were also at higher risk of developing AV (adjusted odds ratio, 3.3) and LDA (adjusted odds ratio, 29.1) than were male cattle. The odds of AV and LDA varied considerably throughout the year, with the lowest number of cases observed in autumn. Seasonal development of AV differed significantly (P less than 0.0001) from that of LDA, with the odds of AV and LDA being highest in January and March, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Polymorphonuclear leukocyte function in cattle with left displaced abomasum with or without concurrent infections

Cattle submitted to the University of Minnesota for surgical correction of left displaced abomasum (LDA) were examined for the in vitro phagocytic and bactericidal activities of their polymorphonuclear leukocytes (PMN). The PMN from cattle with LDA with or without concurrent infection had depressed phagocytic function when compared with PMN from healthy animals (controls). Those with concurrent infection had phagocytic activities lower than those in the group of cattle with LDA without any concurrent infection, and the former group was also observed to have depressed intracellular killing. Cattle with LDA complicated by infection were the only group in which phagocytic function was altered during surgical correction of LDA (and recovery). Treatment of PMN from both groups of affected cattle with levamisole in vitro enhanced intracellular killing, but had no effect on phagocytosis.     

Prognostic indicators in cattle with right-sided displacement of the abomasum and abomasal volvulus]

The records of 106 cases of right-sided displacement of the abomasum (RDA) and abomasal volvulus (AV) were reviewed. Pre- and postoperative heart rate (> or = 90 BPM), serum BUN (> or = 10 mmol/L), potassium (< or = 3.3 mmol/L) and chloride (< or = 85 mmol/L) were the best indicators for a non-productive outcome. High gamma-GT activity can be used as a preoperative indicator to differentiate AV from RDA. The overall rate of return to a productive life was 74% (81.2% of RDA cases and 67.3% of AV cases).     

Preoperative prognostic indicators in cattle with abomasal volvulus

A prospective study evaluating preoperative prognostic indicators in 80 cattle with abomasal volvulus was done. Surgical correction of the abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Mean values for study variables did not differ significantly between salvaged and nonsurvivor groups. Cattle in these 2 groups were combined to form a nonproductive group, which was compared with the productive group. Productive cattle had a significantly lower preoperative heart rate than nonproductive cattle, were less dehydrated, had lower serum alkaline phosphatase (ALP) activity and serum creatinine concentration, more frequent rumen contractions, higher serum Na+ and Cl- concentrations, and had been inappetent for a shorter period. Significant differences were not detected in blood pH, base excess, anion gap, PCV, and serum K+ concentrations between the 2 groups. Feces from nonproductive cattle tended to be reduced in volume and were significantly darker. A number of preoperative prognostic indices were evaluated by calculating the sensitivity, specificity, and positive predictive value (+PV) of each variable and by using logistic regression. Positive predictive values were generally higher in identifying productive cattle than nonproductive cattle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Abomasal volvulus in cattle following correction of left displacement by casting and rolling

Seven adult cows developed abomasal volvulus immediately following correction of left displacement by casting and rolling. Three cows were rolled to provide temporary relief from left displaced abomasum because of concurrent disease and 4 were rolled as the principal therapy for left displacement. In each animal surgical correction of abomasal volvulus was accomplished via right paralumbar fossa celiotomy and inclusion of an omentopexy during abdominal closure. Surgery was performed within 24 hours of casting and rolling. All 7 cows recovered after surgery and were reported to have satisfactory milk production and appetite 6 weeks later.     

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.     

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.     

Phosphorus homeostasis in dairy cows with abomasal displacement or abomasal volvulus

Abnormal phosphorus homeostasis occurs in dairy cows with an abomasal displacement or volvulus. The goal of this study was to identify potential mechanisms for hypophosphatemia and hyperphosphatemia in cows with a left displaced abomasum (LDA), right displaced abomasum (RDA), or abomasal volvulus (AV). Accordingly, the results of preoperative clinicopathologic analyses for 1,368 dairy cows with an LDA (n = 1,189), RDA, or AV (n = 179) (data set 1) and for 44 cows with an AV (data set 2) were retrieved. Laboratory values were compared by Student's t-tests, and correlation and regression analyses were performed. Thirty-four percent of the animals from data set 1 (463/1,368) were hypophosphatemic (serum phosphorus concentration ([Pi]) < 1.4 mmol/L), and 9% (122/1,368) were hyperphosphatemic ([Pi] >2.3 mmol/L). Serum [Pi] was significantly lower (P < .05) in cows with an LDA (1.60 +/- 0.53 mmol/L; mean +/- SD) than in cows with an RDA or AV (1.85 +/- 0.68 mmol/L). For cows with an LDA, [Pi] was correlated with serum urea nitrogen concentration ([SUN]) (r = 0.34) and serum concentration of magnesium ([Mg]) (r = 0.20). For cows with an RDA or AV, linear correlations existed between [Pi] and [SUN] (r = 0.45), [Mg] (r = 0.43), and serum chloride concentration ([Cl]) (r = -0.27). Stepwise logistic regression analysis indicated that low [SUN] and the diagnosis of an LDA had the strongest associations with hypophosphatemia. In cows with hyperphosphatemia, [Pi] was most strongly associated with azotemia. In cows with an AV, the strongest correlations with [Pi] were found for [SUN] and serum creatinine. We conclude that hypophosphatemia in cows with an LDA is primarily due to decreased feed intake. In contrast, hyperphosphatemia in cattle with an RDA or AV appears to result from dehydration and decreased renal blood flow.     

Base excess as a prognostic and diagnostic indicator in cows with abomasal volvulus or right displacement of the abomasum

The case records of 102 cows with abomasal volvulus and 71 cows with right-side displacement of the abomasum (RDA) were examined to determine whether the preoperative base-excess concentration of the extracellular fluid could be used both as a prognostic indicator for post-operative recovery in cattle with abomasal volvulus and as an aid in differentiating between abomasal volvulus and RDA. The survival rate of cows with abomasal volvulus decreased as the base excess concentration decreased (P = 0.08); the lowest survival rate was observed in cows with base excess less than or equal to -0.1 mEq/L. There was a significant difference (0.01 less than P less than 0.025) among base excess ranges between abomasal volvulus and RDA. All cows with preoperative base-excess concentrations less than or equal to -5.0 mEq/L had abomasal volvulus, rather than RDA.     

Prognostic value of surgical and postoperative findings in cattle with abomasal volvulus.

A prospective study evaluating the prognostic value of surgical and postoperative findings in 80 cattle with abomasal volvulus was performed. Surgical correction of abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Cattle with omasal-abomasal volvulus had a significantly (P less than 0.005) worse prognosis than cattle without omasal involvement. Large abomasal fluid volume, venous thrombosis, and blue or black abomasal color before decompression were all indicative of a poor prognosis. Most cattle had poor or fair appetites the first day after surgery; productive animals had marked improvement in appetite over the next 3 days. All cattle observed to have a good appetite within 3 days after surgery were later determined to be productive animals. The heart rate decreased in all groups after surgery; however, tachycardia (heart rate greater than 80 beats/min) was sustained in cattle that were later salvaged for slaughter. Diarrhea was observed after surgery in 54% of cattle. The duration of diarrhea was significantly shorter (P = 0.009) in productive cattle than in salvaged and nonsurviving cattle. The presence or absence of diarrhea was only of predictive value when considered in conjunction with the estimated abomasal fluid volume.     

Decision-tree analysis of treatment alternatives for left displaced abomasum

This study evaluates treatment alternatives for left displaced abomasum (LDA) in dairy cattle. The technique of decision-tree analysis was used to evaluate 3 treatment possibilities. A computerized spreadsheet decision tree was used for the evaluation. Results of this investigation suggested that surgical treatment had the highest expected monetary value. Closed surgical techniques had expected monetary values close to the surgical techniques. Rolling the cow had the lowest expected monetary value, but the expected monetary value for rolling was higher than the expected monetary value for selling. If an LDA recurs after treatment, surgical and closed surgical treatments are preferred over rolling. From this study, we can conclude that surgical and closed surgical treatment alternatives are preferred if expected monetary values are considered. Rolling is preferred over selling the cow. However, if an LDA recurs, selling the cow is preferred over rolling.     

Insulin resistance and abomasal motility disorders in cows detected by use of abomasoduodenal electromyography after surgical correction of left displaced abomasum

OBJECTIVE: To determine the correlation between insulin concentrations and myoelectrical activity of the abomasum in cows with a left displaced abomasum (LDA). ANIMALS: 14 dairy cows with an LDA at the onset of lactation. PROCEDURE: During surgical correction of an LDA, 3 pairs of electrodes were placed in the smooth muscle of the gastrointestinal tract (abomasal body, pars pylorica, and duodenum) of each cow. Electromyographic recordings were obtained once per day for 7 days. Samples were collected and tested to determine concentrations of insulin, glucagon, cortisol, glucose, beta-hydroxybutyrate, and nonesterified fatty acids. RESULTS: All 14 cattle had high glucose and insulin concentrations at the time of admission, independent of ketosis. Concentrations of glucose and insulin decreased slowly after surgical treatment and were associated with a progressive increase in abomasoduodenal myoelectric activity. The 14 cows were allocated into 2 groups (suspected insulin-resistant cattle, n = 7; suspected non-insulin-resistant cattle, 7) on the basis of persistent hyperinsulinemia during the postoperative period. Seven days after surgery, the abomasoduodenal myoelectric patterns were still significantly lower for the insulin-resistant cows, compared with patterns for the non-insulin-resistant cows. CONCLUSIONS AND CLINICAL RELEVANCE: Insulin resistance appears to be common in cows with an LDA. Analysis of results of this study reveals that abomasal atony in cows with an LDA depends on persistence of high serum concentrations of insulin. Results of this study could provide an explanation for a pathogenetic factor of LDAs and the frequent relapses of cattle affected by this condition.     

Origin of abomasum gas in the cows with displaced abomasum

The gas composition of the rumen and the abomasum were investigated in 71 cows including 25 cows with displaced abomasum. The ratio of methane (CH4) to CO2 in the abomasum gas was higher than that in the rumen. In the incubated mixtures of fresh rumen fluid, CH4 was detected at a high concentration, while a small amount of CO2 and CH4 was found in incubated mixtures of fresh abomasum fluids. Hence, it was suggested that the gas in the abomasum originated not from the abomasum itself but from the rumen. In cows fed with mixed roughages and concentrates, the rumen CO2:CH4 ratio was higher compared with cows fed with roughages alone. Marked changes in rumen gas composition were presumed to be associated with changes in abomasum gas composition. Consequently, it is possible that feeding a large quantity of concentrates may increase the flow rate of the ingesta through the forestomach, so that the return rate of gas separated from the ingesta in the abomasum to the forestomach may also increase. Therefore, the frequent accumulation of a large amount of gas with concomitant changes in the total volatile fatty acid (VFA) concentration in the abomasum caused abomasal atony and subsequently displaced abomasum.     

Use of a multiple logistic regression model to determine prognosis of dairy cows with right displacement of the abomasum or abomasal volvulus

Data at admission and at surgery were collected on 458 cows with right displacement of the abomasum or abomasal volvulus, to derive multiple logistic regression models for predicting postsurgical outcome (productive, salvaged, or terminal). The derived models contained few and easily obtained variables. The weight associated with each variable was determined objectively. Three admission variables (heart rate, base excess, and plasma chloride concentration), and 5 surgical variables (heart rate, base excess, diagnosis, method of decompression used, and appearance of abomasal serosa) were used in the final models. Predicted outcomes that used the admission and surgical models were closely related with actual outcomes. Total correct classification for satisfactory (productive) versus unsatisfactory outcome (salvaged and terminal) was 78.2% for the admission model and 82.7% for the surgical model. Combining data on cows with productive and salvaged outcomes as satisfactory outcome, and terminal as unsatisfactory outcome, total correct classification was 90.7% for the admission model and 93.2% for the surgical model. Using predicted probabilities, the market value of productive and salvaged cows, and the medical and surgical costs, one can calculate the expected economic value of each outcome. Treatment can be justified if the sum of the expected value of productive and salvaged outcome exceeds the sum of the medical and surgical costs and the expected salvaged value of the cow that was not treated surgically.