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Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association2026; 67(4); e70188; doi: 10.1111/vru.70188

Renal Perfusion in Healthy Horses: A Feasibility Study With Contrast-Enhanced Ultrasound.

Abstract: This study assessed the feasibility of contrast-enhanced ultrasound (CEUS) for evaluating renal perfusion in horses and compared perfusion parameters between age groups. In a prospective study, eight healthy horses were divided into young (3-5 years, n = 4) and old (16-17 years, n = 4) groups. All animals underwent B-mode, Doppler ultrasonography, and CEUS of the right kidney after an intravenous bolus of SonoVue (0.02 mL/kg). Qualitative analysis assessed contrast kinetics, whereas quantitative parameters (peak intensity, time to peak [TP], area under the curve, and wash-out time) were obtained from time-intensity curves in the renal cortex and medulla. The technique was safely performed in all horses, and the 0.02 mL/kg dose proved optimal for achieving adequate renal enhancement and consistent quantitative measurements. Quantitative analysis revealed a significantly longer TP in the renal cortex of older horses compared to young ones (p = 0.03), suggesting an age-related reduction in perfusion velocity. No other parameters showed significant differences. CEUS proved to be a feasible and safe method for assessing renal perfusion in horses. The prolonged cortical TP in older animals indicates that CEUS may be a sensitive tool for detecting early, subclinical perfusion changes associated with aging, warranting further investigation in horses with renal disease.
© 2026 The Author(s). Veterinary Radiology & Ultrasound published by Wiley Periodicals LLC on behalf of American College of Veterinary Radiology.
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Publication Date: 2026-05-31 PubMed ID: 42216711DOI: 10.1111/vru.70188Google Scholar: Lookup
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  • Journal Article

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 explored the use of contrast-enhanced ultrasound (CEUS) as a safe and viable method to assess kidney blood flow (renal perfusion) in healthy horses of different ages and identified age-related changes in kidney blood flow parameters.

Introduction

  • The kidneys require sufficient blood flow to function properly; changes in renal perfusion can indicate kidney health or disease.
  • Assessing renal perfusion in horses non-invasively is challenging, and existing methods have limitations.
  • Contrast-enhanced ultrasound (CEUS) uses microbubble contrast agents to improve ultrasound imaging of blood flow and has been useful in other species.
  • The goal of the study was to determine if CEUS can be safely and effectively used to evaluate renal perfusion in healthy horses and investigate differences between young and old horses.

Methods

  • Study Design:
    • Prospective study involving eight healthy horses.
    • Horses divided into two groups based on age: young (3-5 years, 4 horses) and old (16-17 years, 4 horses).
  • Procedures:
    • Each horse underwent three imaging techniques on the right kidney: B-mode ultrasound, Doppler ultrasound, and CEUS.
    • The CEUS involved an intravenous bolus injection of SonoVue (a microbubble contrast agent) at a dose of 0.02 mL/kg, optimized for best renal enhancement.
  • Data Collection:
    • Qualitative analysis: Visual assessment of how the contrast moved through the kidney tissue (kinetics).
    • Quantitative analysis: Measurement of time-intensity curves in two main regions of the kidney – the cortex (outer layer) and medulla (inner layer).
    • Key quantitative parameters measured included:
      • Peak intensity (PI) – maximum brightness indicating blood flow volume.
      • Time to peak (TP) – time taken to reach maximum intensity, reflecting perfusion velocity.
      • Area under the curve (AUC) – overall blood volume passing through over time.
      • Wash-out time – how quickly contrast leaves the tissue.

Results

  • Safety and Feasibility:
    • The CEUS technique was safely performed on all horses with no adverse effects.
    • The chosen contrast dose (0.02 mL/kg of SonoVue) provided clear and consistent kidney enhancement suitable for measurement.
  • Perfusion Parameters:
    • A significant finding was that the Time to Peak (TP) in the renal cortex was longer in older horses compared to young horses (p = 0.03).
    • This suggests that blood flows more slowly through the cortex in older horses, indicating an age-related decline in renal perfusion velocity.
    • No significant differences between age groups were found for other parameters such as peak intensity, area under curve, or wash-out time.

Discussion and Implications

  • CEUS is demonstrated as a practical, non-invasive imaging tool to assess kidney blood flow in horses.
  • Age-related prolongation in cortical TP suggests that CEUS can detect early, subtle reductions in renal blood flow that may not be apparent with other methods.
  • This sensitivity is clinically important as it could help identify early kidney changes before overt disease develops.
  • Future studies are warranted to evaluate CEUS in horses with kidney disease or other health conditions to further validate its diagnostic utility.
  • The study provides baseline perfusion data for healthy equine kidneys, aiding future comparative research.

Conclusion

  • Contrast-enhanced ultrasound is a feasible, safe, and effective method to evaluate renal perfusion in horses.
  • Older horses exhibit slower cortical renal perfusion as detected by prolonged time to peak contrast enhancement, indicating possible early changes in kidney blood flow with aging.
  • CEUS shows promise as a tool for monitoring kidney health and detecting early perfusion alterations in equine veterinary medicine.

Cite This Article

APA
(2026). Renal Perfusion in Healthy Horses: A Feasibility Study With Contrast-Enhanced Ultrasound. Vet Radiol Ultrasound, 67(4), e70188. https://doi.org/10.1111/vru.70188

Publication

Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association
ISSN: 1740-8261
NlmUniqueID: 9209635
Country: England
Language: English
Volume: 67
Issue: 4
Pages: e70188

Researcher Affiliations

MeSH Terms

  • Animals
  • Horses / physiology
  • Contrast Media
  • Feasibility Studies
  • Kidney / diagnostic imaging
  • Kidney / blood supply
  • Ultrasonography / veterinary
  • Ultrasonography / methods
  • Male
  • Sulfur Hexafluoride
  • Female
  • Phospholipids
  • Prospective Studies
  • Renal Circulation / physiology
  • Ultrasonography, Doppler / veterinary
  • Aging / physiology
  • Age Factors

Grant Funding

  • -FinanceCode001. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES)

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