FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Equine veterinary journal2026; doi: 10.1002/evj.70140

Mono-dimensional, two-dimensional and Doppler echocardiographic measurements in healthy Standardbred neonatal foals in the first 5 days of life.

Abstract: Bodyweight, age and breed influence the echocardiographic assessment of foals. There are no echocardiographic studies in Standardbred neonatal foals. Objective: To describe echocardiographic values for selected variables, evaluate intra- and inter-observer variability and assess cardiac changes in the first 5 days of life in healthy Standardbred neonatal foals. Methods: Prospective observational study. Methods: Fifty-six healthy Standardbred neonatal foals were examined by transthoracic echocardiography using standard right parasternal and subcostal views at three time points: in the first 48 h (T1), between 49 and 96 h (T2), and 97 and 144 h (T3) after birth. Descriptive statistics, variability analysis and linear mixed models assessed age-related changes in cardiac parameters. Intra/inter-observer variability was assessed using intraclass correlation coefficients (ICC). Results: A total of 114 echocardiographic examinations were performed. Intra-observer agreement was excellent for most variables, while inter-observer agreement was excellent in approximately half. An increase in end-diastolic left ventricular internal diameter (T1: 5.3 ± 0.6 cm; T3: 5.6 ± 0.8 cm; p < 0.01), left atrial diameter in the four-chamber view (T1: 5.8 ± 0.6 cm; T3: 6.0 ± 0.6 cm; p = 0.01), end-diastolic aortic sinus diameter in the left ventricular outflow tract view (T1: 3.0 ± 0.3 cm; T3: 3.2 ± 0.3 cm; p < 0.01) and peak velocity of the transmitral E wave (T1: 0.8 ± 0.1 m/s; T3: 0.9 ± 0.1 m/s; p < 0.01) were observed over time. Additionally, a gradual decrease in the end-diastolic pulmonary diameter at the sinus (T1: 2.8 ± 0.3 cm; T3: 2.5 ± 0.3 cm; p < 0.01) and at the valve (T1: 2.6 ± 0.3 cm; T3: 2.5 ± 0.4 cm; p = 0.03) levels was noted. Conclusions: Some variables have fewer individuals; coefficients of variation are moderate to high for some variables. Conclusions: Changes in echocardiographic variables in a healthy Standardbred neonatal foal population reflect a physiological adaptation of the cardiorespiratory system from foetal to extrauterine life. These observations can be used as a reference in the assessment of neonatal foals of similar age and weight.
© 2026 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Get Full Text
Publication Date: 2026-01-06 PubMed ID: 41493062DOI: 10.1002/evj.70140Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • 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 establishes normal heart ultrasound (echocardiographic) measurements in healthy newborn Standardbred foals during their first five days of life.
  • It evaluates how heart measurements change in the initial days after birth and examines the reliability of these measurements when taken by the same or different observers.

Background and Objective

  • Bodyweight, age, and breed are known to affect heart ultrasound assessments in foals.
  • Prior to this study, no echocardiographic data existed specifically for Standardbred neonatal foals, which is a common horse breed.
  • The study aimed to:
    • Describe typical heart ultrasound values for certain heart measurements in these foals.
    • Assess how consistent these measurements are when repeated by the same observer (intra-observer variability) and different observers (inter-observer variability).
    • Identify how these heart measurements change physiologically during the first 5 days after birth.

Methods

  • Study design: Prospective observational study involving 56 healthy Standardbred neonatal foals.
  • The foals underwent transthoracic echocardiographic exams at three time periods after birth:
    • T1: Within the first 48 hours
    • T2: Between 49 and 96 hours
    • T3: Between 97 and 144 hours
  • Echocardiograms used standard right parasternal and subcostal imaging views to capture heart structures and blood flow.
  • Statistical analyses included descriptive statistics, variability analyses, and linear mixed models to detect age-related heart parameter changes.
  • Reliability of measurements was assessed using intraclass correlation coefficients (ICC) for both intra- and inter-observer variability.

Key Results

  • A total of 114 echocardiographic exams were performed across the foal cohort.
  • Intra-observer variability (the same person repeating measurements) showed excellent agreement for most heart variables, indicating high measurement consistency.
  • Inter-observer variability (different people making measurements) showed excellent agreement about half the time, reflecting some variability depending on the measurer.
  • Significant changes in heart measurements were observed over the 5-day period, including:
    • Increase in end-diastolic left ventricular internal diameter (from 5.3 cm to 5.6 cm).
    • Increase in left atrial diameter measured in the four-chamber heart view (from 5.8 cm to 6.0 cm).
    • Increase in end-diastolic aortic sinus diameter observed in the left ventricular outflow tract view (from 3.0 cm to 3.2 cm).
    • Increase in peak velocity of the transmitral E wave, indicating changes in blood flow speed during heart filling (from 0.8 m/s to 0.9 m/s).
    • Decrease in the pulmonary artery diameter at both the sinus and valve levels (from 2.8 cm to 2.5 cm and from 2.6 cm to 2.5 cm respectively).
  • Some measurements had fewer foals contributing data, and there was moderate to high variability (coefficient of variation) in some variables.

Conclusions and Implications

  • The observed changes in heart size and blood flow parameters reflect normal physiological adaptations as the foal’s cardiovascular and respiratory systems transition from fetal to postnatal life.
  • The values and trends documented can serve as reference standards for veterinarians assessing healthy Standardbred foals at a similar age and bodyweight.
  • The study highlights the importance of using consistent measurement techniques to reduce observer variability in echocardiographic assessments.
  • These findings improve understanding of normal cardiac development in neonatal Standardbred foals, assisting in the early detection of cardiac abnormalities in this breed.

Cite This Article

APA
D'el Rey Dantas FT, Forni G, Hallowell G, Castagnetti C, Menchetti L, Romito G, Lanci A, Mariella J, Freccero F. (2026). Mono-dimensional, two-dimensional and Doppler echocardiographic measurements in healthy Standardbred neonatal foals in the first 5 days of life. Equine Vet J. https://doi.org/10.1002/evj.70140

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

D'el Rey Dantas, Fernanda Timbó
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Forni, Giulia
  • Department of Animal Medicine, Production and Health, University of Padova, Padova, Italy.
Hallowell, Gayle
  • Medicine Vet Equine Referrals, Leicestershire, UK.
Castagnetti, Carolina
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Menchetti, Laura
  • School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy.
Romito, Giovanni
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Lanci, Aliai
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Mariella, Jole
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Freccero, Francesca
  • Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.

References

This article includes 43 references
  1. Corley KTT. Monitoring and treating the cardiovascular system in neonatal foals. Clin Tech Equine Pract 2003;2:42–55.
    doi: 10.1016/s1534-7516(03)000179google scholar: lookup
  2. Marr CM. The equine neonatal cardiovascular system in health and disease. Vet Clin North Am Equine Pract 2015;31:545–565.
    doi: 10.1016/j.cveq.2015.09.005google scholar: lookup
  3. Freccero F, Romito G, Beato C, Mariella J, Lanci A, Ellero N. Echocardiographic assessment of fluid‐responsiveness in critically ill newborn foals: a pilot study. J Vet Intern Med 2022;36:2449.
    doi: 10.1111/jvim.16541google scholar: lookup
  4. Giguere S. Research and clinical expertise in hemodynamic monitoring of critically ill foals. In: Proceedings of the ACVIM Forum and Canadian VMA Convention, Montreal, Quebec, Canada. 2009.
  5. Ribonnet C. The equine neonatal cardiovascular system. UK‐Vet Equine 2024;8:225–233.
    doi: 10.12968/ukve.2023.0055google scholar: lookup
  6. Bakos Z, Vörös K, Järvinen T, Reiczigel J. Two‐dimensional and M‐mode echocardiographic measurements of cardiac dimensions in healthy Standardbred trotters. Acta Vet Hung 2002;50:273–282.
    doi: 10.1556/avet.50.2002.3.3google scholar: lookup
  7. Collins N, Palmer L, Marr C. Two‐dimensional and M‐mode echocardiographic findings in healthy Thoroughbred foals. Aust Vet J 2010;88:428–433.
    doi: 10.1111/j.1751-0813.2010.00641.xgoogle scholar: lookup
  8. Freccero F, Cordella A, Dondi F, Castagnetti C, Niinistö K, Cipone M. Feasibility of the echocardiographic subcostal view in newborn foals: two‐dimensional and Doppler aortic findings. Equine Vet J 2018;50:865–869.
    doi: 10.1111/evj.12832google scholar: lookup
  9. Al‐Haidar A, Moula N, Leroux A, Farnir F, Deleuze S, Sandersen C. Reference values of two‐dimensional and M‐mode echocardiographic measurements as a function of body size in various equine breeds and in ponies. J Vet Cardiol 2017;19:492–501.
    doi: 10.1016/j.jvc.2017.08.008google scholar: lookup
  10. Sleeper MM, Durando MM, Holbrook TC, Payton ME, Birks EK. Comparison of echocardiographic measurements in elite and nonelite Arabian endurance horses. Am J Vet Res 2014;75:893–898.
    doi: 10.2460/ajvr.75.10.893google scholar: lookup
  11. Zucca E, Ferrucci F, Croci C, Di Fabio V, Zaninelli M, Ferro E. Echocardiographic measurements of cardiac dimensions in normal Standardbred racehorses. J Vet Cardiol 2008;10:45–51.
    doi: 10.1016/j.jvc.2008.04.002google scholar: lookup
  12. Lombard CW, Evans M, Martin L, Tehrani J. Blood pressure, electrocardiogram and echocardiogram measurements in the growing pony foal. Equine Vet J 1984;16:342–347.
    doi: 10.1111/j.2042-3306.1984.tb01939.xgoogle scholar: lookup
  13. Stewart JH, Rose RJ, Bark AM. Echocardiography in foals from birth to three months old. Equine Vet J 1984;19:332–341.
    doi: 10.1111/j.2042-3306.1984.tb01938.xgoogle scholar: lookup
  14. Slack J, Durando MM, Belcher CN, Collins N, Palmer L, Ousey J. Intraoperator, intraobserver and interoperator variability of echocardiographic measurements in healthy foals. Equine Vet J 2012;44:69–75.
    doi: 10.1111/j.2042-3306.2011.00503.xgoogle scholar: lookup
  15. Fernandes T, Uberti B, Robin M. Changes in measurable ultrasonographic parameters in growing Arabian foals from birth to 1 year. Equine Vet J 2025;58:157–164.
    doi: 10.1111/evj.14520google scholar: lookup
  16. Rovira S, Muñoz A. Two‐dimensional and M‐Mode echocardiographic measurements and indices of cardiac function in Spanish colts and fillies of different age. J Vet Med Sci 2009;71:957–964.
    doi: 10.1292/jvms.71.957google scholar: lookup
  17. Vaala WE, House JK, Madigan JE. Initial management and physical examination of the neonate. In: Smith BP, editor. Large animal internal medicine. 3rd ed. St. Louis, MO: Mosby; 2002. p. 277–293.
  18. de Navas Solis C. Fetal circulation and cardiorespiratory transition. In: Wong DM, Wilkins PA, editors. Equine neonatal medicine. Chichester: Wiley‐Blackwell; 2024. p. 45–67.
  19. Long KJ, Bonagura JD, Darke PGG. Standardised imaging technique for guided M‐mode and Doppler echocardiography in the horse. Equine Vet J 1992;24:226–235.
    doi: 10.1111/j.2042-3306.1992.tb02820.xgoogle scholar: lookup
  20. Fleiss JL. The design and analysis of clinical experiments. New York: Wiley‐Interscience; 2011.
  21. Friedrichs KR, Harr KE, Freeman KP, Szladovits B, Walton RM, Barnhart KF. ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics. Vet Clin Pathol 2012;41:441–453.
    doi: 10.1111/vcp.12006google scholar: lookup
  22. Grenacher PA, Schwarzwald CC. Assessment of left ventricular size and function in horses using anatomical M‐mode echocardiography. J Vet Cardiol 2010;12:111–121.
    doi: 10.1016/j.jvc.2010.01.002google scholar: lookup
  23. Chakkarapani AA, Roehr CC, Hooper SB, Te Pas AB, Gupta S. Transitional circulation and hemodynamic monitoring in newborn infants. Pediatr Res 2024;96:595–603.
    doi: 10.1038/s41390-022-02427-8google scholar: lookup
  24. Oberhänsli I, Brandon G, Lacourt G, Friedli B. Growth patterns of cardiac structures and changes in systolic time intervals in the newborn and infant: a longitudinal echocardiographic study. Acta Paediatr 1980;69:239–247.
    doi: 10.1111/j.1651-2227.1980.tb07068.xgoogle scholar: lookup
  25. Morton SU, Brodsky D. Fetal physiology and the transition to extrauterine life. Clin Perinatol 2016;43:395–407.
    doi: 10.1016/j.clp.2016.04.001google scholar: lookup
  26. Erbel R, Schweizer P, Krebs W, Langen H‐J, Meyer J, Effert S. Effects of heart rate changes on left ventricular volume and ejection fraction: a 2‐dimensional echocardiographic study. Am J Cardiol 1984;53:590–597.
    doi: 10.1016/0002-9149(84)90036-5google scholar: lookup
  27. Fries RC, Clark‐Price SC, Kadotani S, Stack JP, Schaeffer DJ, Lascola KM. Quantitative assessment of left ventricular volume and function by transthoracic and transesophageal echocardiography, ultrasound velocity dilution, and gated magnetic resonance imaging in healthy foals. Am J Vet Res 2020;81:930–939.
    doi: 10.2460/ajvr.81.12.930google scholar: lookup
  28. Constantine G, Shan K, Flamm SD, Sivananthan MU. Role of MRI in clinical cardiology. Lancet 2004;363:2162–2171.
    doi: 10.1016/s0140-6736(04)16509-4google scholar: lookup
  29. Yamanaka T, Oku K, Koyama H, Mizuno Y. Time‐related changes of the cardiovascular system during maintenance anesthesia with sevoflurane and isoflurane in horses. J Vet Med Sci 2001;63:527–532.
    doi: 10.1292/jvms.63.527google scholar: lookup
  30. De Lange L, Vernemmen I, Van Loon G, Decloedt A. Echocardiographic features of the ductus arteriosus and the foramen ovale in a hospital‐based population of neonatal foals. Animals 2022;12:2242.
    doi: 10.3390/ani12172242google scholar: lookup
  31. Macdonald AA, Fowden AL, Silver M, Ousey J, Rossdale PD. The foramen ovale of the foetal and neonatal foal. Equine Vet J 1988;20:255–260.
    doi: 10.1111/j.2042-3306.1988.tb01517.xgoogle scholar: lookup
  32. Machida N, Yasuda J, Too K. A morphometric study of foetal and newborn cardiac growth in the horse. Equine Vet J 1988;20:261–267.
    doi: 10.1111/j.2042-3306.1988.tb01519.xgoogle scholar: lookup
  33. Giguère S, Bucki E, Adin DB, Valverde A, Estrada AH, Young L. Cardiac output measurement by partial carbon dioxide rebreathing, 2‐dimensional echocardiography, and lithium‐dilution method in anesthetized neonatal foals. J Vet Intern Med 2005;19:737–743.
    doi: 10.1111/j.1939-1676.2005.tb02754.xgoogle scholar: lookup
  34. Decloedt A, De Clercq D, Ven Sofie S, Van Der Vekens N, Sys S, Broux B. Echocardiographic measurements of right heart size and function in healthy horses. Equine Vet J 2017;49:58–64.
    doi: 10.1111/evj.12554google scholar: lookup
  35. Boon JA. Veterinary echocardiography. 2nd ed. Ames, IA: Wiley‐Blackwell; 2011.
  36. Hu Q, Ren WD, Mao J, Li J, Qiao W, Bi WJ. Changes in pulmonary artery pressure during early transitional circulation in healthy full‐term newborns. Ultrasonics 2015;56:524–529.
    doi: 10.1016/j.ultras.2014.10.005google scholar: lookup
  37. Kang C, Zhao E, Zhou Y, Zhao H, Liu Y, Gao N. Dynamic changes of pulmonary arterial pressure and ductus arteriosus in human newborns from birth to 72 hours of age. Medicine (Baltimore) 2016;95:e2599.
    doi: 10.1097/md.0000000000002599google scholar: lookup
  38. Marr CM, Bowen IM. Cardiology of the horse. 2nd ed. Edinburgh: Saunders/Elsevier; 2010.
  39. Clinical and Laboratory Standards Institute. Defining, establishing, and verifying reference intervals in the clinical laboratory: approved guideline. 3rd ed. Wayne: CLSI; 2010.
  40. Blissitt KJ, Young LE, Jones RS, Darke PGG, Utting J. Measurement of cardiac output in standing horses by Doppler echocardiography and thermodilution. Equine Vet J 1997;29:18–25.
    doi: 10.1111/j.2042-3306.1997.tb01631.xgoogle scholar: lookup
  41. McConachie E, Barton MH, Rapoport G, Giguère S. Doppler and volumetric echocardiographic methods for cardiac output measurement in standing adult horses. J Vet Intern Med 2013;27:324–330.
    doi: 10.1111/jvim.12034google scholar: lookup
  42. Roustaei A, Masoudifard M, Azari O, Keshipour H, Koohestani O. Echocardiographic and clinical effects of two sedative doses of dexmedetomidine in healthy horses. J Equine Vet Sci 2025;146:105382.
    doi: 10.1016/j.jevs.2025.105382google scholar: lookup
  43. Schwarzwald C. Equine echocardiography. Vet Clin North Am Equine Pract 2019;35:43–64.
    doi: 10.1016/j.cveq.2018.12.008google scholar: lookup

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 100,227 horse owners like you who receive our email updates on horse health and nutrition.