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Abstract

OBJECTIVE To evaluate use of a telemetric gastrointestinal (GI) pill to continuously monitor GI temperature in horses at rest and during exercise and to compare time profiles of GI temperature and rectal temperature.

ANIMALS 8 Standardbred horses.

PROCEDURES Accuracy and precision of the GI pill and a rectal probe were determined in vitro by comparing temperature measurements with values obtained by a certified resistance temperature detector (RTD) in water baths at various temperatures (37°, 39°, and 41°C). Subsequently, both GI and rectal temperature were recorded in vivo in 8 horses over 3 consecutive days. The GI temperature was recorded continuously, and rectal temperature was recorded for 3.5 hours daily. Comparisons were made between GI temperature and rectal temperature for horses at rest, during exercise, and after exercise.

RESULTS Water bath evaluation revealed good agreement between the rectal probe and RTD. However, the GI pill systematically underestimated temperature by 0.14°C. In vivo, GI temperature data were captured with minimal difficulties. Most data loss occurred during the first 16 hours, after which the mean ± SD data loss was 8.6 ± 3.7%. The GI temperature was consistently and significantly higher than rectal temperature with an overall mean temperature difference across time of 0.27°C (range, 0.22° to 0.32°C). Mean measurement cessation point for the GI pill was 5.1 ± 1.0 days after administration.

CONCLUSIONS AND CLINICAL RELEVANCE This study revealed that the telemetric GI pill was a reliable and practical method for real-time monitoring of GI temperature in horses.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To determine whether infrared thermographic images obtained the morning after overnight heat abatement could be used as the basis for diagnostic algorithms to predict subsequent heat stress events in feedlot cattle exposed to high ambient temperatures.

ANIMALS 60 crossbred beef heifers (mean ± SD body weight, 385.8 ± 20.3 kg).

PROCEDURES Calves were housed in groups of 20 in 3 pens without any shade. During the 6 am and 3 pm hours on each of 10 days during a 14-day period when the daily ambient temperature was forecasted to be > 29.4°C, an investigator walked outside each pen and obtained profile digital thermal images of and assigned panting scores to calves near the periphery of the pen. Relationships between infrared thermographic data and panting scores were evaluated with artificial learning models.

RESULTS Afternoon panting score was positively associated with morning but not afternoon thermographic data (body surface temperature). Evaluation of multiple artificial learning models indicated that morning body surface temperature was not an accurate predictor of an afternoon heat stress event, and thermographic data were of little predictive benefit, compared with morning and forecasted weather conditions.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated infrared thermography was an objective method to monitor beef calves for heat stress in research settings. However, thermographic data obtained in the morning did not accurately predict which calves would develop heat stress later in the day. The use of infrared thermography as a diagnostic tool for monitoring heat stress in feedlot cattle requires further investigation.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To develop 2 rapid loop-mediated isothermal amplification (LAMP) assays for detection of Pasteurella multocida DNA (Pm-LAMP assay) and P multocida DNA from strains associated with hemorrhagic septicemia (HS) in cattle and buffalo (HS-LAMP assay).

SAMPLE Solutions containing 16 P multocida strains and 9 other bacterial species at various concentrations.

PROCEDURES Optimal conditions were determined for running the Pm-LAMP and HS-LAMP assays. The assays were then used to detect DNA of the test organisms. Results of LAMP assays were validated against conventional PCR assays designed for specific detection of P multocida and the B:2 serotype of HS-associated strains.

RESULTS Following incubation of sample reaction mixtures for 27 minutes, specificity and sensitivity of the HS-LAMP assay at template DNA amounts as low as 5 pg were 93% and 97%, respectively. When duplicates of each sample were incubated for 28 minutes (a positive result defined as positive results for both reactions of a given sample), specificity and sensitivity of the HS-LAMP assay in the same conditions increased to 100%. The best specificity and sensitivity of Pm-LAMP single (93% and 91%) and duplicate (97% and 98%) reactions at template DNA amounts as low as 10 pg were achieved at 33 and 34 minutes, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE These preliminary findings suggested the developed HS-LAMP assay had high sensitivity and specificity for detection of HS-associated P multocida. Additional research is needed to determine the accuracy of the assay for use on clinical specimens obtained in HS-endemic countries such as Pakistan and Thailand.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate the effect of intra-abdominal pressure (IAP) on morphology and compliance of the lower esophageal sphincter (LES) by use of impedance planimetry in healthy dogs and to quantify the effect of changes in IAP.

ANIMALS 7 healthy, purpose-bred sexually intact male hound-cross dogs.

PROCEDURES Dogs were anesthetized, and cross-sectional area (CSA), minimal diameter (MD), LES length, LES volume, and distensibility index (DI) of the LES were evaluated by use of an endoscopic functional luminal imaging probe. For each dog, measurements were obtained before (baseline) and after creation of a pneumoperitoneum at an IAP of 4, 8, and 15 mm Hg. Order of the IAPs was determined by use of a randomization software program.

RESULTS CSA and MD at 4 and 8 mm Hg were not significantly different from baseline measurements; however, CSA and MD at 15 mm Hg were both significantly greater than baseline measurements. The LES length and LES volume did not differ significantly from baseline measurements at any IAP. The DI differed inconsistently from the baseline measurement but was not substantially affected by IAP.

CONCLUSIONS AND CLINICAL RELEVANCE Pneumoperitoneum created with an IAP of 4 or 8 mm Hg did not significantly alter LES morphology in healthy dogs. Pneumoperitoneum at an IAP of 15 mm Hg caused a significant increase in CSA and MD of the LES. Compliance of the LES as measured by the DI was not greatly altered by pneumoperitoneum at an IAP of up to 15 mm Hg.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To identify variations in glucose values concurrently obtained by use of a continuous glucose monitoring system (CGMS) at the same site, reliability of results for each site, lag time for each site, and influence of site thickness on CGMS accuracy.

ANIMALS 8 random-source research dogs.

PROCEDURES In experiment 1, 8 CGMS sensors were implanted bilaterally at 1 site (4 sensors/side) in 4 dogs. In experiment 2, 2 CGMS sensors were implanted bilaterally at each of 4 sites (1 sensor/side) in 8 dogs; 4 of those 8 dogs then were subjected to a glycemic clamp technique. The CGMS results were compared among sensors and with criterion-referenced results during periods of euglycemia for all 8 dogs and during hyperglycemia and hypoglycemia for 4 dogs during the glycemic clamp procedure.

RESULTS Differences (median, −7 mg/dL; interquartile range [IQR], −18.75 to 3 mg/dL) between CGMS and criterion-referenced glucose concentrations differed significantly among dogs and sites; during euglycemia, they were not different from the expected normal variation between multiple sensors concurrently implanted at the same site. Differences (median, −35 mg/dL; IQR, −74 to −15 mg/dL) between CGMS and criterion-referenced concentrations were greater during changes in glucose concentrations. Thoracic sensors were most accurate but had the shortest mean functional life.

CONCLUSIONS AND CLINICAL RELEVANCE Significant differences were detected between CGMS and criterion-referenced glucose concentrations. Overall clinical utility of CGMS was acceptable at all sites, with most of the values from all sensors, sites, and dogs meeting guidelines for point-of-care glucometers.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To validate the use of high-resolution manometry (HRM) in awake, healthy dogs and compare the effects of bolus type (liquid vs solid) and drug treatment (saline [0.9% NaCl] solution [SS] vs cisapride) on esophageal pressure profiles.

ANIMALS 8 healthy dogs.

PROCEDURES In a crossover study, each dog received SS (10 mL) IV, and HRM was performed during oral administration of 10 boluses (5 mL each) of water or 10 boluses (5 g each) of canned food. Cisapride (1 mg/kg in 60 mL of SS) was subsequently administered IV to 7 dogs; HRM and bolus administration procedures were repeated. Two to 4 weeks later, HRM was repeated following administration of SS and water and food boluses in 4 dogs. Pressure profile data were obtained for all swallows, and 11 outcome variables were statistically analyzed.

RESULTS After SS administration, predicted means for the esophageal contractile integral were 850.4 cm/mm Hg/s for food boluses and 660.3 cm/mm Hg/s for water boluses. Predicted means for esophageal contraction front velocity were 6.2 cm/s for water boluses and 5.6 cm/s for food boluses after SS administration. Predicted means for residual LES pressure were significantly higher following cisapride administration.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that HRM was feasible and repeatable in awake healthy dogs of various breeds and sizes. Stronger esophageal contractions and faster esophageal contraction velocity occurred during solid bolus and liquid bolus swallows, respectively. Lower esophageal sphincter pressure increased significantly following cisapride administration. Esophageal contractions and bolus transit latency should be further evaluated by HRM in clinically dysphagic dogs.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To investigate associations between inertial sensor and stationary force plate measurements of hind limb lameness in horses.

ANIMALS 21 adult horses with no lameness or with mild hind limb lameness.

PROCEDURES Horses were instrumented with inertial sensors and evaluated for lameness with a stationary force plate while trotting in a straight line. Inertial sensor–derived measurements of maximum and minimum pelvic height differences between right and left halves of the stride were compared with vertical and horizontal ground reaction forces (GRFs). Stepwise linear regression was performed to investigate the strength of association between inertial sensor measurements of hind limb lameness and amplitude, impulse, and time indices of important events in the vertical and horizontal GRF patterns.

RESULTS Difference in minimum pelvic position was moderately (R a 2 = 0.60) associated with the difference in peak vertical GRF but had little association with any horizontal GRF measurements. Difference in maximum pelvic position was strongly (R a 2 = 0.77) associated with a transfer of vertical to horizontal ground reaction impulse in the second half of the stance but was not associated with difference in peak vertical GRF.

CONCLUSIONS AND CLINICAL RELEVANCE Inertial sensor–derived measurements of asymmetric pelvic fall (difference in minimum pelvic position) indicated a decrease in vertical GRF, but similar measurements of asymmetric pelvis rise (difference in maximum pelvic position) indicated a transfer of vertical to horizontal force impulse in the second half of the stance. Evaluation of both pelvic rise and fall may be important when assessing hind limb lameness in horses.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate plasma interleukin 6 (IL-6) concentration in Standardbred racehorses by means of a novel ELISA following validation of the assay for use with equine plasma samples.

SAMPLE Plasma samples obtained from 25 Thoroughbreds for use in assay validation and from 319 Standardbred racehorses at rest 2 to 2.5 hours prior to warm-up and racing.

PROCEDURES A sandwich ELISA was developed with equine anti–IL-6 polyclonal antibody and the biotin-streptavidin chemical interaction to enhance sensitivity. The assay was validated for specificity, sensitivity, precision, and accuracy by use of both recombinant and endogenous proteins.

RESULTS For the assay, cross-reactivity with other human and equine cytokines was very low or absent. Serial dilution of plasma samples resulted in proportional decreases in reactivity, indicating high specificity of the method. Partial replacement of detection antibody with capture antibody or pretreatment of samples with capture antibody caused assay signals to significantly decrease by 55%. The inter- and intra-assay precisions were ≤ 13.6% and ≤ 9.3%, respectively; inter- and intra-assay accuracies were within ranges of ± 14.1% and ± 8.6%, respectively, at concentrations from 78 to 5,000 pg/mL, and the sensitivity was 18 pg/mL. Plasma IL-6 concentration varied widely among the 319 Standardbreds at rest (range, 0 to 193,630 pg/mL; mean, 6,153 pg/mL; median, 376 pg/mL).

CONCLUSIONS AND CLINICAL RELEVANCE This ELISA method proved suitable for quantification of IL-6 concentration in equine plasma samples. Plasma IL-6 concentration was high (> 10,000 pg/mL) in 9.1% of the Standardbred racehorses, which warrants further investigation.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To assess intraobserver repeatability and interobserver and in vivo versus photographic agreement of a scoring system for the implant-skin interface (ISI) of external skeletal fixation (ESF).

SAMPLE 42 photographs of ISIs from 18 dogs for interobserver agreement and intraobserver repeatability and 27 photographs of ISIs from 6 dogs for in vivo versus photograph agreement.

PROCEDURES An ISI inflammation scoring system was developed. It included scales for 6 metrics (erythema, drainage amount, drainage type, swelling, hair loss or lack of hair regrowth, and granulation tissue). Photographs of the ISI of ESF were obtained by use of a standard protocol and evaluated to determine intraobserver repeatability and interobserver agreement (Cronbach α; 4 raters) of the ISI score. Agreement between in vivo and photographic ISI scores (2 raters) and correlation between median scores across metrics were evaluated.

RESULTS 42 photographs met the inclusion criteria. Overall intraclass correlation coefficients ranged from 0.922 to 0.975. Interobserver overall Cronbach α ranged from 0.835 to 0.943. For in vivo versus photographic assessment, 27 ISIs in 6 dogs and their photographs were evaluated. The Cronbach α for both raters ranged from 0.614 to 0.938. Overall, the Cronbach α ranged from 0.725 to 0.932. Mean photographic scores were greater than mean in vivo scores for each metric. Pearson correlation coefficients ranged from 0.221 to 0.923. Erythema, swelling, and granulation were correlated with all other metrics.

CONCLUSIONS AND CLINICAL RELEVANCE In this study, an ISI scoring system used in this study had high repeatability and agreement and may therefore be considered for use in clinical situations. Photographic scores were not equivalent to in vivo scores and should not be used interchangeably.

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To determine changes in dimensions of feline skin samples as a result of histologic processing and to identify factors that contributed to changes in dimensions of skin samples after sample collection.

SAMPLE Cadavers of 12 clinically normal cats.

PROCEDURES Skin samples were obtained bilaterally from 3 locations (neck, thorax, and tibia) of each cadaver; half of the thoracic samples included underlying muscle. Length, width, and depth were measured at 5 time points (before excision, after excision, after application of ink to mark tissue margins, after fixation in neutral-buffered 10% formalin for 36 hours, and after completion of histologic processing and staining with H&E stain). Measurements obtained after sample collection were compared with measurements obtained before excision.

RESULTS At the final time point, tissue samples had decreased in length (mean decrease, 32.40%) and width (mean decrease, 34.21%) and increased in depth (mean increase, 54.95%). Tissue from the tibia had the most shrinkage in length and width and that from the neck had the least shrinkage. Inclusion of underlying muscle on thoracic skin samples did not affect the degree of change in dimensions.

CONCLUSIONS AND CLINICAL RELEVANCE In this study, each step during processing from excision to formalin fixation and histologic processing induced changes in tissue dimensions, which were manifested principally as shrinkage in length and width and increase in depth. Most of the changes occured during histologic processing. Inclusion of muscle did not affect thoracic skin shrinkage. Shrinkage should be a consideration when interpreting surgical margins in clinical cases. 945)

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in American Journal of Veterinary Research