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Abstract

OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses.

ANIMALS 12 healthy adult research horses.

PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential expression of the fecal and gastric microbiota. Data were analyzed by visual examination and by statistical methods.

RESULTS Composition and diversity of the fecal microbiota did not differ significantly between treatment groups or over time. Substantial variation in gastric fluid results within groups and over time precluded meaningful interpretation of the microbiota in those samples.

CONCLUSIONS AND CLINICAL RELEVANCE Results supported that omeprazole administration had no effect on fecal microbiota composition and diversity in this group of healthy adult horses. Small sample size limited power to detect a difference if one existed; however, qualitative graphic examination supported that any difference would likely have been small and of limited clinical importance. Adequate data to evaluate potential effects on the gastric microbiota were not obtained. Investigations are needed to determine the effects of omeprazole in horses with systemic disease or horses receiving other medical treatments.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether the concentrations of airborne virulent Rhodococcus equi in stalls housing foals during the first 2 weeks after birth are associated with subsequent development of R equi pneumonia in those foals.

Sample—Air samples collected from foaling stalls and holding pens in which foals were housed during the first 2 weeks after birth.

Procedures—At a breeding farm in Texas, air samples (500 L each) were collected (January through May 2011) from stalls and pens in which 121 foals were housed on day 1 and on days 4, 7, and 14 after birth. For each sample, the concentration of airborne virulent R equi was determined with an immunoblot technique. The association between development of pneumonia and airborne R equi concentration was evaluated via random-effects Poisson regression analysis.

Results—Some air samples were not available for analysis. Of the 471 air samples collected from stalls that housed 121 foals, 90 (19%) contained virulent R equi. Twenty-four of 121 (20%) foals developed R equi pneumonia. Concentrations of virulent R equi in air samples from stalls housing foals that developed R equi pneumonia were significantly higher than those in samples from stalls housing foals that did not develop pneumonia. Accounting for disease effects, air sample concentrations of virulent R equi did not differ significantly by day after birth or by month of birth.

Conclusions and Clinical Relevance—Exposure of foals to airborne virulent R equi during the first 2 weeks after birth was significantly (and likely causally) associated with development of R equi pneumonia.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine concentrations of 2 acute-phase proteins (serum amyloid A [SAA] and lipopolysaccharide-binding protein [LBP]) in serum samples obtained from horses with colic and identify relationships among these acute-phase proteins and clinical data.

Animals—765 horses with naturally developing gastrointestinal tract diseases characterized by colic (ie, clinical signs indicative of abdominal pain) and 79 healthy control horses; all horses were examined at 2 university teaching hospitals.

Procedure—Serum concentrations of SAA and LBP were determined by immunoturbidometric and dotblot assays, respectively.

Results—SAA and LBP concentrations were determined for 718 and 765 horses with colic, respectively. Concentrations of SAA were significantly higher in nonsurvivors than in survivors, and horses with enteritis or colitis and conditions characterized by chronic inflammation (eg, abdominal abscesses, peritonitis, or rectal tears) had SAA concentrations significantly greater than those for horses with other conditions. Serum concentrations of LBP did not correlate with outcome, disease process, or portion of the gastrointestinal tract affected.

Conclusions and Clinical Relevance—Circulating concentrations of SAA were significantly higher at admission in horses with colic attributable to conditions having a primary inflammatory cause (eg, enteritis, colitis, peritonitis, or abdominal abscesses) and were higher in horses that failed to survive the episode of colic, compared with concentrations in horses that survived. Serum concentrations of LBP did not correlate with survival. Analysis of these findings suggests that evaluation of SAA concentrations may be of use in identifying horses with colic attributable to diseases that have inflammation as a primary component of pathogenesis. (Am J Vet Res 2005;66:1509–1516)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate a real-time quantitative polymerase chain reaction (QPCR) assay in the detection and quantitation of virulent Rhodococcus equi.

Sample Population—1 virulent, 2 intermediately virulent, and 2 avirulent strains of R equi and 16 isolates of bacteria genetically related to R equi.

Procedure—The QPCR assay was evaluated for detection and quantitation of the virulence-associated gene (vapA) of R equi in pure culture and in samples of tracheobronchial fluid, which were inoculated with known numbers of virulent R equi. Results were compared with those derived via quantitative microbial culture and standard polymerase chain reaction methods.

Results—The QPCR assay detected the vapAgene in pure culture of R equi and in tracheobronchial fluid samples that contained as few as 20 CFUs of virulent R equi/mL and accurately quantitated virulent R equi to 103 CFUs/mL of fluid. The assay was highly specific for detection of the vapA gene of virulent R equi and was more sensitive than standard polymerase chain reaction for detection of R equi in tracheobronchial fluid.

Conclusions and Clinical Relevance—The QPCR assay appears to be a rapid and reliable method for detecting and quantitating virulent R equi. The accuracy of the QPCR assay is comparable to that of quantitative microbial culture. The increased sensitivity of the QPCR method in detection of virulent R equi should facilitate rapid and accurate diagnosis of R equi pneumonia in foals. (Am J Vet Res 2005;66:755–761)

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in American Journal of Veterinary Research

Abstract

Objective—To characterize the temporality of dates of breeding and abortion classified as mare reproductive loss syndrome (MRLS) among mares with abortions during early gestation.

Animals—2,314 mares confirmed pregnant at approximately 28 days after breeding from 36 farms in central Kentucky, including 515 mares that had earlyterm abortions.

Procedure—Farm veterinarians and managers were interviewed to obtain data for each mare that was known to be pregnant to determine pregnancy status, breeding date, last date known to be pregnant, and date of abortion.

Results—Mares bred prior to April 1, 2001, appeared to be at greatest risk of early-term abortion, both among and within individual farms. Mares bred in mid-February appeared to be at greatest risk of abortion, with an estimated weekly incidence rate of abortion of 66% (95% CI, 52% to 80%).

Conclusions and Clinical Relevance—Mares in central Kentucky bred between mid-February and early March were observed to be at greatest risk of early-term abortion, and risk gradually decreased to a background incidence of abortion of approximately 11%. Mares bred after April 1, 2001, appeared to be at markedly less risk, indicating that exposure to the cause of MRLS likely occurred prior to this date. (Am J Vet Res 2005;66:1792–1797)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To estimate spatial risks associated with mare reproductive loss syndrome (MRLS) during 2001 among horses in a specific study population and partition the herd effects into those attributable to herd location and those that were spatially random and likely attributable to herd management.

Animals—Pregnant broodmares from 62 farms in 7 counties in central Kentucky.

Procedure—Veterinarians provided the 2001 abortion incidence proportions for each farm included in the study. Farms were georeferenced and data were analyzed by use of a fully Bayesian risk-mapping technique.

Results—Large farm-to-farm variation in MRLS incidence proportions was identified. The farm-to-farm variation was largely attributed to spatial location rather than to spatially random herd effects

Conclusions and Clinical Relevance—Results indicate that there are considerable data to support an ecologic cause and potential ecologic risk factors for MRLS. Veterinary practitioners with more detailed knowledge of the ecology in the 7 counties in Kentucky that were investigated may provide additional data that would assist in the deduction of the causal factor of MRLS via informal geographic information systems analyses and suggest factors for inclusion in further investigations. (Am J Vet Res 2005;66:17–20)

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen.

Animals—6 mature horses.

Procedure—Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness of fit of the data. Serial serum samples were taken, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 240 minutes and the absorption constant (Ka) were determined, using a parameter estimation program. Correlations were calculated, using the Spearman rank correlation coefficient.

Results—Correlations between T50 and Tmax and between T50 and Ka were significant.

Conclusions and Clinical Relevance—Tmax and Ka are valuable variables in the assessment of liquidphase gastric emptying using acetaminophen absorption. Acetaminophen absorption may be a valuable alternative to nuclear scintigraphy in the determination of gastric emptying rates in equine patients with normally functioning small intestine. (Am J Vet Res 2000;61:310–315)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the correlation between the half-time of liquid-phase gastric emptying (T50) determined by use of nuclear scintigraphy, using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen in horses with experimentally delayed gastric emptying.

Animals—6 mature horses.

Procedure—Delayed gastric emptying was induced by IV injection of atropine sulfate. Twenty minutes later, acetaminophen and technetium Tc 99m pentetate were administered simultaneously via nasogastric tube. Serial lateral images of the stomach region were obtained, using a gamma camera. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness-of-fit of the data. Serial serum samples were obtained, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 480 minutes, and the appearance rate constant were determined, using a parameter estimation program. Correlations were calculated, using a Spearman rank correlation coefficient.

Results—A significant correlation was detected between T50 determined by use of scintigraphy and Tmax determined by use of acetaminophen absorption. Correlation between T50 and other absorption variables of acetaminophen was not significant.

Conclusions and Clinical Relevance—The acetaminophen absorption method was a valid technique in this model of delayed gastric emptying in horses. The method may be a valuable tool for use in research as well as in clinical evaluation of gastric emptying in horses. (Am J Vet Res 2002;63:170–174)

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate quality of duodenal tissue specimens obtained endoscopically from dogs and cats and submitted to 1 of 2 diagnostic laboratories for evaluation.

Design—Case series.

Sample Population—Slides from 50 consecutive canine and 50 consecutive feline endoscopically obtained duodenal tissue specimens submitted to laboratory 1 and 49 consecutive canine and 46 consecutive feline specimens submitted to laboratory 2.

Procedure—Slides were examined independently by 3 investigators, and each tissue piece on each slide was classified as clearly inadequate, questionable, or clearly adequate on the basis of 4 criteria. An overall score was then assigned to the slide.

Results—Slides from laboratory 1 were more likely to be scored as clearly adequate and less likely to be scored as clearly inadequate than slides from laboratory 2. Clearly adequate slides from laboratory 1 had a higher number of clearly adequate pieces of tissue than did clearly adequate slides from laboratory 2. Slides scored as clearly adequate had a higher number of individual tissue pieces than did slides scored as clearly inadequate.

Conclusions and Clinical Relevance—Results suggest that the quality of endoscopically obtained duodenal tissue specimens submitted to laboratories can vary, possibly because of differences in experience of individuals collecting biopsy specimens. Results suggest that at least 8 individual tissue pieces should be submitted when performing endoscopic biopsy of the duodenum in dogs and cats. (J Am Vet Med Assoc 2001;219:474–479)

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the association between high-speed exercise and risk of injury while racing among Thoroughbreds in Kentucky.

Design—Matched case-control study.

Animals—206 Thoroughbreds that sustained a musculoskeletal injury while racing and 412 Thoroughbreds that were not injured during the same races.

Procedure—Data regarding official timed workouts and races and the Beyer's numbers for the 3 races before the race during which injury occurred were extracted from past performance charts and compared between injured horses and control horses.

Results—For injured horses, cumulative distance of high-speed exercise during the 1- and 2-month periods prior to the race in which injury occurred was significantly less than that of control horses; for either period, a difference of 10 furlongs was associated with approximately 2-fold greater risk of injury. Beyer's numbers were significantly higher for injured horses than for control horses. These effects remained significant after adjusting for age and results of prerace physical inspection.

Conclusions and Clinical Relevance—In Kentucky, injured horses had significantly less cumulative highspeed exercise than did control horses during the 1- and 2-month periods prior to the race in which injury occurred. These results differ from those observed in California. The association of injury with cumulative high-speed exercise appears to vary among regions in the United States. (J Am Vet Med Assoc 2000; 216:1273–1278)

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in Journal of the American Veterinary Medical Association