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Abstract

Objective—To determine and compare the effects of erythromycin, neostigmine, and metoclopramide on abomasal motility and emptying rate in suckling calves.

Animals—6 male Holstein calves (15 to 40 days of age).

Procedure—Calves were monitored for 1 hour before being fed milk replacer (60 mL/kg; time, 0 minutes) and then were monitored for another 3 hours. Calves received 6 treatments in randomized order: erythromycin (8.8 mg/kg, IM) at –30 minutes; low-dose erythromycin (0.88 mg/kg, IM) at –30 minutes; erythromycin (8.8 mg/kg, IM) at –30 minutes and neostigmine (0.02 mg/kg, SC) at –30 and 90 minutes; neostigmine (0.02 mg/kg, SC) at –30 and 90 minutes; metoclopramide (0.1 mg/kg, IM) at –30 and 90 minutes; and placebo (2 mL of saline [0.9% NaCl] solution, SC) at –30 minutes. Abomasal volume was calculated from ultrasonographic measurements of abomasal width, length, and height. Abomasal motility and emptying rate were assessed by measuring luminal pressure and change in abomasal volume over time.

Results—Administration of erythromycin (8.8 mg/kg) increased the frequency of abomasal luminal pressure waves and the mean abomasal luminal pressure and decreased the half-time of abomasal emptying by 37%. Administration of metoclopramide, neostigmine, and low-dose erythromycin (0.88 mg/kg) did not alter abomasal motility, mean luminal pressure, or emptying rate.

Conclusions and Clinical Relevance—Results indicated that administration of erythromycin at the labeled antimicrobial dose (8.8 mg/kg, IM) exerted an immediate, marked prokinetic effect in healthy suckling calves, whereas administration of metoclopramide or neostigmine did not alter abomasal motility or emptying rate. (Am J Vet Res 2005;66:545–552)

Full access
in American Journal of Veterinary Research

Abstract

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. ( Am J Vet Res 2004; 65:597–603)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare the effects of surgical correction of left displaced abomasum (LDA) by means of omentopexy via right flank laparotomy or 2-step laparoscopy-guided abomasopexy on postoperative abomasal emptying rate in lactating dairy cows.

Design—Controlled clinical trial.

Animals—30 lactating dairy cows with an LDA.

Procedures—Cows were alternately assigned to 2 groups of 15 cows each to receive surgical correction of LDA by means of 2-step laparoscopy-guided abomasopexy or omentopexy via right flank laparotomy. A 50% D-xylose solution (0.5 g/kg [0.23 g/lb]) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum D-xylose concentration were periodically obtained after injection. Abomasal emptying rate was evaluated by pharmacokinetic determination of the time to modeled maximal serum D-xylose concentration (Tmax-model).

Results—Mean ± SD abomasal emptying rate was significantly faster after laparoscopy-guided abomasopexy (Tmax-model, 192 ± 51 minutes) than after omentopexy via right flank laparotomy (Tmax-model, 264 ± 94 minutes). Rumen contraction rate and milk yield increased faster after laparoscopy-guided abomasopexy, compared with values obtained after omentopexy; however, milk yield did not differ after the 2 procedures.

Conclusions and Clinical Relevance—Amelioration of abomasal hypomotility after laparoscopy-guided abomasopexy rather than omentopexy via right flank laparotomy may result in faster clinical improvement in the immediate postoperative period in cows undergoing correction of an LDA.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To develop nuclear scintigraphic and acetaminophen absorption methods for measuring abomasal emptying rate in suckling calves.

Animals—9 male Holstein-Friesian calves < 30 days old.

Procedure—Calves were fed 2 L of milk replacer, fresh cow's milk, or an isoosmotic (150mM) solution of NaCl, NaHCO3, or sodium acetate containing technetium TC 99m-diethylenetriamine-pentaacetic acid (370 MBq) and acetaminophen (50 mg/kg). Right lateral scintigraphic images and venous blood samples were obtained periodically after feeding. Two power exponential equations were fitted to the scintigraphic data, and 3 pharmacokinetic models were fitted to the acetaminophen concentration–time data.

Results—Data from 32 feedings were analyzed, with half emptying time for scintigraphic evaluation ranging from 29 to 202 minutes. Siegel's modified power exponential equation provided a better description of the scintigraphic data than did Elashoff's power exponential equation. The first derivative of Siegel's modified power exponential formula provided the best pharmacokinetic model for the acetaminophen absorption data. Time to maximal acetaminophen concentration (Tmax) provided the most accurate index of abomasal emptying rate from the acetaminophen concentration–time data.

Conclusions and Clinical Relevance—Abomasal emptying rate is best determined in healthy suckling calves by use of Siegel's modified power exponential equation to model the scintigraphic data. Pharmacokinetic calculation of Tmax from the acetaminophen absorption curve provides an alternative method for determining abomasal emptying rate in healthy suckling calves that is accurate, inexpensive, practical, and safe. However, it is unclear whether diarrhea would alter the acetaminophen absorption curve in calves. (Am J Vet Res 2005;66:364–374)

Full access
in American Journal of Veterinary Research

Abstract

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. (Am J Vet Res 2005;66:537–544)

Full access
in American Journal of Veterinary Research

Abstract

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 midline. (J Am Vet Med Assoc 2005;227:1469–1475)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine clinical examination findings, clinicopathologic abnormalities, and outcome of treatment in dairy cattle with abomasal impaction.

Design—Retrospective study.

Animals—80 lactating Holstein-Friesian cows ≥ 2 years old.

Procedure—Medical records of cattle with abomasal impaction admitted between 1980 and 2003 were retrieved, and data were extracted.

Results—All cows were reported to have decreased food intake; concurrent diseases were identified in 54 (68%). Seventeen cows did not have detectable ruminal motility, but physical examination findings were nonspecific and variable. In general, cattle had mild hypocalcemia, hyperbilirubinemia, and hyperglycemia, but serum potassium and chloride concentrations were typically within reference limits. Fifty-five (69%) cattle had impaction of the pyloric antrum alone, and 25 (31%) had impaction of the abomasal body and pyloric antrum. Right flank laparotomy and abomasal massage were performed in 73 cattle. After surgery, 54 (74%) cattle received 3 to 4 L of mineral oil, PO, daily for 1 to 5 days. Short-term (ie, discharged from the hospital) survival rate was significantly higher for cows with impaction of the pyloric antrum alone (42/45 [93%]) than for cows with impaction of the body and antrum (12/24 [50%]).

Conclusions and Clinical Relevance—Results suggest that physical examination findings and results of serum biochemical analyses do not facilitate the diagnosis of abomasal impaction in lactating Holstein cows and that exploratory right flank laparotomy is necessary to make the diagnosis. Abomasal impaction should be considered as a differential diagnosis for inappetence and poor milk production in lactating dairy cows. (J Am Vet Med Assoc 2005;227:287–291)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether preoperative administration of erythromycin or flunixin meglumine altered postoperative abomasal emptying rate, rumen contraction rate, or milk production in dairy cattle undergoing surgical correction of left displacement of the abomasum (LDA).

Design—Nonrandomized, controlled clinical trial.

Animals—45 lactating Holstein-Friesian cows with LDA.

Procedures—Cows were alternately assigned to an erythromycin (10 mg/kg [4.5 mg/lb], IM), flunixin (2.2 mg/kg [1.0 mg/lb], IV), or control group (n = 15/group). Treatments were administered once 1 hour before surgical correction of LDA. D-Xylose solution (50%; 0.5 g/kg [0.23 g/lb]) was injected into the abomasal lumen during surgery, and venous blood samples were periodically obtained to determine time to maximum serum D-xylose concentration.

Results—Abomasal emptying rate was significantly faster in cows treated with erythromycin (mean ± SD time to maximum serum D-xylose concentration, 149 ± 48 minutes) than in control cows (277 ± 95 minutes) but was not significantly different between cows treated with flunixin (230 ± 49 minutes) and control cows. Cows treated with erythromycin had significantly greater milk production, relative to production before surgery, on postoperative days 1 and 2 than did control cows. Cows in the erythromycin and flunixin groups had a significantly higher rumen contraction rate on the first postoperative day than did control cows.

Conclusions and Clinical Relevance—Results suggested that preoperative administration of a single dose of erythromycin increased abomasal emptying rate, rumen contraction rate, and milk production in the immediate postoperative period in cows undergoing surgical correction of LDA.

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in Journal of the American Veterinary Medical Association

Abstract

Objectives—To compare abomasal emptying rates in calves after suckling milk replacer or 3 common orally administered electrolyte solution components.

Animals—5 male calves < 35 days of age.

Procedures—Calves with a cannula fitted in the abomasal body were fed 2 L of milk replacer with or without parenteral administration of atropine (0.01 mg/kg, IV, then 0.02 mg/ kg, SC, q 30 min) or isotonic (150mM) solutions of sodium acetate, NaHCO3, or NaCl in a randomized crossover design. Abomasal emptying rates were determined via scintigraphy, acetaminophen absorption, ultrasonography, and change in abomasal luminal pH.

Results—Scintigraphic half-emptying time, time of maximal plasma acetaminophen concentration, ultrasonographic half-emptying time, and pH return time indicated similar abomasal emptying rates following suckling of isotonic sodium acetate, NaHCO3, and NaCl solutions, whereas the emptying rate of milk replacer was significantly slower. Mean maximal abomasal luminal pH was highest following suckling of NaHCO3 (pHmax = 7.85) and lowest following suckling of NaCl (pHmax = 4.52); sodium acetate (pHmax = 6.59) and milk replacer (pHmax = 5.84) yielded intermediate pH values.

Conclusions and Clinical Relevance—Isotonic solutions of sodium acetate, NaHCO3, and NaCl were rapidly emptied from the abomasum but varied markedly in their ability to alkalinize the abomasum. Sodium bicarbonate–containing orally administered electrolyte solution might increase the frequency of infection or severity of clinical disease in diarrheic calves treated for dehydration by causing prolonged abomasal alkalinization.

Full access
in American Journal of Veterinary Research