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behaviour
nutrition
riding science
2022
Case Report

Inflammatory Response and Electrocardiographic Examination in Horses Vaccinated against Equine Herpesvirus (Ehv-1).

Authors: Biondi Vito, Landi Alessandra, Pugliese Michela, Merola Giordana, Passantino Annamaria

Journal: Animals : an open access journal from MDPI

Summary

# Editorial Summary: Cardiac Inflammation Following EHV-1 Vaccination Vaccination programmes are fundamental to equine health management, yet potential adverse effects on cardiac tissue remain underexplored. This investigation examined 18 healthy horses receiving inactivated EHV-1 vaccine (Pneumoequine®), measuring electrocardiographic changes alongside cardiac troponin I (cTnI) and inflammatory markers (serum amyloid A and C-reactive protein) at baseline, 7 days and 14 days post-vaccination. Notably, the study identified abnormalities in electrocardiographic findings concurrent with elevated inflammatory biomarkers following vaccination, suggesting subclinical myocardial involvement driven by the inflammatory response to immunisation. Although the clinical significance of these electrocardiographic changes requires further investigation—particularly regarding whether they represent transient physiological responses or warrant concern in performance horses—practitioners should be aware that EHV-1 vaccination may trigger measurable cardiac inflammation in some individuals. Further research characterising the duration and intensity of these changes, and identifying risk factors for exaggerated responses, would help optimise vaccination protocols and post-vaccination monitoring strategies for at-risk populations.

Read the full abstract on PubMed

Practical Takeaways

  • Monitor vaccinated horses for cardiac signs within 1-2 weeks post-vaccination, particularly if clinical signs of myocarditis develop
  • Be aware that EHV-1 inactivated vaccines may cause transient myocardial inflammation; baseline cardiac assessment may be prudent in at-risk individuals
  • Consider staggered vaccination protocols or medical monitoring in horses with pre-existing cardiac conditions or sensitivity to vaccine reactions

Key Findings

  • Inactivated EHV-1 vaccination triggered measurable changes in cardiac troponin I (cTnI) in healthy horses
  • Serum amyloid A (SAA) and C-reactive protein (CRP) increased following vaccination, indicating inflammatory response
  • Electrocardiographic abnormalities were detected post-vaccination, suggesting myocardial involvement
  • Peak inflammatory markers and cardiac changes occurred within 7-14 days post-vaccination

Conditions Studied

equine herpesvirus-1 (ehv-1)vaccine responsemyocardial inflammationcardiac biomarker elevation