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Australian veterinary journal2026; doi: 10.1111/avj.70068

Imaging of the equine abdomen using point of care ultrasound (POCUS): Effects of sedation on intestinal motility in horses.

Abstract: Point of care ultrasonographic (POCUS) assessment of the equine abdomen is now readily available to the equine practitioner using hand-held ultrasound transducers. Commonly used medications may alter the sonographic appearance or function of the small intestine, caecum or colon. Objective: To demonstrate qualitative and quantitative effects of xylazine sedation on intestinal motility of healthy horses using hand-held, wi-fi ultrasound transducers and validate POCUS methodology by determination of intra- and interobserver agreement. Methods: Double-blind cross-over study of eight healthy horses using hand-held, wi-fi ultrasound transducers to determine the effects of sedation on intestinal motility in comparison with administration of a placebo (saline). Motility was independently assessed by three observers using deidentified videos obtained using hand-held, wi-fi ultrasound transducers. Agreement was assessed by determination of intraclass correlation coefficient (number of duodenal contractions) and weighted kappa statistic for motility grades. Results: Sedation was associated with fewer duodenal contractions (median 0.5, range 0 to 2) after sedation, compared with administration of saline (median 4, range 3 to 5, p < 0.001). Large colon and composite motility grades were also reduced (median 4.5, range 2 to 6 after sedation; median 10, range 7 to 12, after saline, p = 0.005), and qualitative changes were evident in the sonographic appearance of jejunal loops in six of eight horses. Interobserver agreement was moderate to good, and intraobserver agreement was good to excellent. Conclusions: POCUS proved to be an effective tool to recognise qualitative and quantitative changes associated with sedation.
© 2026 The Author(s). Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.
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Publication Date: 2026-03-22 PubMed ID: 41866886DOI: 10.1111/avj.70068Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study examined how sedation with xylazine affects intestinal motility in healthy horses by using hand-held, wi-fi ultrasound devices (POCUS) and assessed the reliability of this method by analyzing observer agreement.

Background and Purpose

  • Point of care ultrasound (POCUS) is increasingly accessible for veterinarians working with horses, particularly for abdominal imaging.
  • Common sedatives used in horses may influence the movement and appearance of intestinal structures (small intestine, caecum, and colon) on ultrasound.
  • The study aimed to:
    • Demonstrate both qualitative (visual) and quantitative (measurable) effects of xylazine sedation on intestinal motility in horses.
    • Validate the POCUS technique by assessing consistency and reliability between different observers (interobserver) and within the same observer over time (intraobserver).

Methods

  • Study design:
    • Double-blind cross-over design to minimize bias.
    • Eight healthy horses were included.
    • Each horse received both xylazine sedation and saline placebo on different occasions.
  • Imaging:
    • Used hand-held, wi-fi-enabled ultrasound transducers for abdominal imaging.
    • Videos of the intestines were recorded before and after administration of sedation or placebo.
  • Motility Assessment:
    • Three independent observers assessed intestinal motility from deidentified videos.
    • Two measures were used:
      • Quantitative: Number of duodenal contractions.
      • Qualitative: Graded motility scoring for large colon and composite intestinal regions.
  • Statistical analysis:
    • Intraclass correlation coefficient (ICC) to measure agreement for number of duodenal contractions.
    • Weighted kappa statistics for motility grade agreement.
    • Comparative statistics to assess differences between sedation and placebo conditions.

Results

  • Effect of sedation on intestinal motility:
    • Duodenal contractions were significantly decreased after sedation (median 0.5 contractions) compared to saline (median 4 contractions), indicating reduced small intestinal motility.
    • Large colon and composite motility scores were similarly reduced after sedation (median 4.5) compared to saline (median 10), showing sedation suppresses motility across intestinal regions.
    • Visual changes were noted in the appearance of jejunal loops in six out of eight horses under sedation, indicating qualitative alterations in the ultrasound image.
  • Observer agreement:
    • Interobserver agreement (between different observers) was moderate to good, suggesting consistent ratings across observers.
    • Intraobserver agreement (consistency within the same observer) was good to excellent, indicating reproducible measurements over time.
    • This validates that POCUS assessments are reliable for evaluating intestinal motility in horses.

Conclusions and Implications

  • Point of care ultrasound is an effective tool for identifying both qualitative and quantitative changes in intestinal motility caused by sedation in horses.
  • Using hand-held, wireless ultrasound devices enables practical and reliable assessment in clinical or field settings.
  • Veterinarians should consider the effects of sedatives like xylazine on intestinal motility and sonographic appearance when interpreting POCUS findings.
  • The demonstrated observer agreement supports the use of POCUS as a consistent method for abdominal evaluation in equine practice.

Cite This Article

APA
Freccero F, Padalino B, Carstens A, Raidal SL. (2026). Imaging of the equine abdomen using point of care ultrasound (POCUS): Effects of sedation on intestinal motility in horses. Aust Vet J. https://doi.org/10.1111/avj.70068

Publication

Australian veterinary journal
ISSN: 1751-0813
NlmUniqueID: 0370616
Country: England
Language: English

Researcher Affiliations

Freccero, F
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Padalino, B
  • Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia.
  • Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy.
Carstens, A
  • School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia.
Raidal, S L
  • School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia.
  • Melbourne Veterinary School, The University of Melbourne, Werribee, Victoria, Australia.

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