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.     

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.     

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.     

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.     

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 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.     

81例奶牛真胃右方变位和真胃扭转临床诊断治疗及体会

报道了南京地区 81例奶牛真胃右方变位 (RAD)和真胃扭转 (AV)的发病情况、临床症状、剖检变化、诊断和治疗过程 ,并就RAD和AV在奶牛胎次、产后天数、病程天数等方面进行了比较 ;详述了RAD和AV各自临床症状、诊断特点、治疗方法上的差异以及作者对手术固定方法的改进 ,同时对病因、预后等进行了讨论。     

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 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).     

Cecal dilatation and volvulus in dairy cows: 84 cases (1977-1983)

The records of 84 cows with cecal dilatation or cecal volvulus were reviewed. The diagnosis was made by exploratory laparotomy or necropsy in 21 cows with cecal dilatation, and in 45 cows with cecal volvulus. Eighteen of the cows with cecal dilatation responded to medical management and the diagnosis was made by physical examination alone. The most useful criteria for determining that surgery was necessary were the presence of a high heart rate, apparent abdominal pain, scant or absence of feces, and the apex of the cecum rotated cranially on rectal examination. The prognosis for cattle with cecal dilatation and volvulus was good following medical therapy or decompression at surgery unless there was severe vascular compromise of the cecum. There was a 10% recurrence rate, and in these cows a partial typhlectomy was performed.     

Left-side displacement of the abomasum in dairy cows at pasture

The presentation of approximately 40 dairy cows affected with left-side displacement of the abomasum (LDA) per annum in a cattle practice in East Gippsland, Victoria provided an opportunity to conduct a survey and case-control study of the disease in a grazing environment. The study, involving 37 dairy cows at pasture, revealed significant differences from the pattern of the disease occurring in the northern hemisphere where cows in older age groups, of larger frame size, higher production and fed high grain rations are at increased risk. Affected cows were diagnosed over a 10-month period and represented approximately 0.06% of the dairy cow population. Most cases were diagnosed in the early lactation period. Evidence for a genetic predisposition was suggested by the discovery that one sire generated a disproportionately large number (9) of the cows with LDA. Although affected cows were average producers in their herds, being a member of a high-producing herd was a significant risk factor.     

Risk factors for abomasal displacement in dairy cows.

OBJECTIVE: To determine whether various periparturient events or 305-day milk production during the previous lactation period were associated with abomasal displacement in dairy cows. DESIGN: Retrospective, case-control study. ANIMALS: 75 pairs of case and control cows from 3 university-owned and 3 commercial dairy herds. PROCEDURE: Cows with abomasal displacement were matched with control cows on the basis of herd of origin, breed, age, and calving date. Frequency of specific periparturient events during the period from 2 weeks prior to parturition to diagnosis of abomasal displacement, as well as milk production during the preceding lactation period, were compared between case and control cows. RESULTS: Multivariate analyses indicated that case cows were significantly more likely to have had retained placenta, ketosis, a stillborn calf, metritis, twins, or parturient paresis than were control cows. Dystocia, mastitis, and milk production during the previous lactation period were not associated with abomasal displacement. CLINICAL IMPLICATIONS: Results indicated that a variety of periparturient events were associated with development of abomasal displacement among dairy cows.     

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.     

Prognostic value of anion gap calculation in cattle with abomasal volvulus: 58 cases (1980-1985)

Values for anion gap, serum chloride, and base excess were tabulated for 58 dairy cows with abomasal volvulus. Test values for survivors (n = 40) and nonsurvivors (n = 18) were compared. Surviving cattle were released for production or salvage. Nonsurviving cows died or were euthanatized. Accuracy of preoperative anion gap, serum chloride, and base excess values in predicting outcome was evaluated by calculating the sensitivity, specificity, predictive value, and negative predictive value of these at assigned cutoff values. Anion gaps greater than or equal to 30 mEq/L were indicative of a poor prognosis. At this value, the sensitivity (0.889), specificity (0.925), predictive value (0.842), negative predictive value (0.949), and efficiency (0.914) were higher than when serum chloride concentration less than or equal to 84 mEq/L or base excess value less than or equal to 0 were used to denote poor prognosis. We concluded that preoperative anion gap calculation could reliably predict the outcome of cows with abomasal volvulus and was more accurate than either serum chloride concentration or base excess value.     

Ultrasonographic examination of the omasum, liver, and small and large intestines in cows with right displacement of the abomasum and abomasal volvulus

OBJECTIVE: To describe ultrasonographic appearance of the liver, small and large intestines, and omasum in cows with right displacement of the abomasum (RDA) and with abomasal volvulus (AV) and to determine whether RDA and AV can be differentiated on the basis of ultrasonographic findings. ANIMALS: 17 cows with RDA, 9 cows with AV, and 10 healthy control cows. PROCEDURES: A linear transducer was used to examine the abomasum, liver, omasum, and small and large intestines from the right side. Results-The liver was imaged less frequently in cows with RDA or AV, compared with control cows. In 9 cows with RDA or AV, the liver could not be imaged. The small intestine was imaged less frequently in cows with RDA or AV than in control cows; in cows with AV, the small intestine could not be imaged in the 8th, 9th, or 10th intercostal space. The large intestine was imaged less frequently in the 11th and 12th intercostal spaces and the cranial region of the flank in cows with RDA or AV. The omasum was also imaged less frequently in the 8th and 9th intercostal spaces in cows with RDA or AV. Cows with RDA or AV could not be differentiated on the basis of ultrasonographic findings. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with control cows, cows with RDA and AV had changes in positioning and therefore extent of ultrasonographic imaging of the liver, omasum, and small and large intestines; however, these findings were not useful in differentiating between cows with RDA and AV.     

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.     

奶牛真胃变位发病规律的研究

为了阐明奶牛真胃变位的发病规律，对263例奶牛患有真胃变位的自然病例进行了研究。结果表明：真胃变位的发生与过食精料和高产奶牛有密切关系，2－4胎次体格健壮的、产后30天内的、11月份到来年的5月份奶牛发病率高。