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Home / Equine Research Bank / BMC Vet Res / Detection and genetic characterization of equine viruses in ...
BMC veterinary research2025; 21(1); 119; doi: 10.1186/s12917-025-04613-2

Detection and genetic characterization of equine viruses in Sweden using viral metagenomics.

Abstract: Viral infections pose a significant challenge to the equine population, compromising welfare and causing substantial economic losses for the global equine industry. While numerous equine viral pathogens have been identified, many suspected viral infections remain undiagnosed. This highlights the need for further identification and characterization of viruses circulating within the equine population. In this study, we utilized viral metagenomics to investigate viruses present in serum samples and nasal swabs collected from horses in Sweden. The primary focus was on horses presenting with fever, although control horses were also included for comparison. Results: The viral metagenomic analysis identified several viruses in the investigated samples. Among nasal swabs, the majority of the viral reads were classified as various equine herpesvirues (EHVs), mainly EHV-2 and EHV-5. Other viruses in nasal swabs include but are not limited to EHV-4, Torque teno equus virus 1 (TTeqV1) and equine copiparvovirus (eqCopV). Both TTeqV1 and eqCopV were also detected in the serum samples together with equine circovirus and equine pegivirus. A number of the detected viruses were further genetically characterized and were shown to display high sequence similarity to viruses from the US and/or China. qPCR screening of a selected number of the detected viruses revealed a rather low detection rate (1.6%-9.4%) in individual horses. Conclusions: This study identified several viruses that circulate in the horse population in Sweden, some of which have not been previously detected in Sweden or Europe. Furthermore, the complete or nearly complete genomes of several of these viruses have been genetically characterized. These new data provide a valuable foundation for developing improved detection assays and conducting larger prevalence studies to assess the potential impact of these viruses on the equine population. Such efforts could ultimately contribute to enhanced equine welfare.
© 2025. The Author(s).
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Publication Date: 2025-02-27 PubMed ID: 40011862PubMed Central: PMC11866639DOI: 10.1186/s12917-025-04613-2Google 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.

This study focuses on identifying and characterizing various viruses found in horses in Sweden, primarily those with fever symptoms. Several types of viruses were detected, some newly identified in Europe or Sweden, providing significant information to develop better detection tools and assess the potential impacts on the equine population.

Study Design and Methodology

  • The researchers collected serum samples and nasal swabs from horses in Sweden to analyze viral metagenomics, specifically focusing on horses presenting with fever. They also included control horses for comparison.
  • They performed a metagenomic analysis on these samples to identify the presence of different types of viruses, such as Equine Herpesvirus (EHV).
  • Following the detection of the viruses, they genetically characterized them to gain deeper insights into their nature. They identified the ones that displayed high sequence similarity to viruses from other regions such as the US and China.
  • Finally, using qPCR screening, the research team tested a selected number of the detected viruses in individual horses, indicating a low detection rate.

Key Findings

  • The viral metagenomic analysis identified several viruses in the investigated samples. EQ Herpesvirus-2 and EQHerpesvirus-5 were found in majority of the nasal swabs.
  • The discovery of other viruses, such as EQHerpesvirus-4, Torque teno equus virus 1 (TTeqV1) and equine copiparvovirus (eqCopV) in nasal swabs and TTeqV1, eqCopV, equine circovirus and equine pegivirus in serum samples further expanded the spectrum of viral presence.
  • These identified viruses were found to have high genetic similarities to viruses identified in the United States and/or China.
  • qPCR screening of these viruses, however, revealed a low detection rate, ranging between 1.6% to 9.4% in individual horses.

Conclusions and Implications

  • This study successfully identified several viruses within the horse population in Sweden, including some viruses not previously detected in Europe or Sweden.
  • The genetic characterization offered comprehensive insights into these viruses and indicated similarity to viruses from other regions.
  • Although the study demonstrated a low detection rate, this study contributes valuable data for better virus detection development and larger prevalence studies.
  • This information enables more profound assessments of potential viral impacts on the horse population, eventually leading to improved equine welfare.

Cite This Article

APA
Blomström AL, Källse A, Riihimäki M. (2025). Detection and genetic characterization of equine viruses in Sweden using viral metagenomics. BMC Vet Res, 21(1), 119. https://doi.org/10.1186/s12917-025-04613-2

Publication

BMC veterinary research
ISSN: 1746-6148
NlmUniqueID: 101249759
Country: England
Language: English
Volume: 21
Issue: 1
Pages: 119

Researcher Affiliations

Blomström, Anne-Lie
  • Department of Animal Biosciences, Swedish University of Agricultural Sciences, Uppsala, Sweden. anne-lie.blomstrom@slu.se.
Källse, Annika
  • Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Riihimäki, Miia
  • Department of Animal Biosciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
  • Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.

MeSH Terms

  • Animals
  • Horses / virology
  • Sweden / epidemiology
  • Horse Diseases / virology
  • Horse Diseases / epidemiology
  • Metagenomics
  • Virus Diseases / veterinary
  • Virus Diseases / virology
  • Virus Diseases / epidemiology
  • Viruses / genetics
  • Viruses / isolation & purification
  • Viruses / classification
  • Phylogeny

Grant Funding

  • H-20-47-555 / The Swedish-Norwegian Foundation for Equine Research

Conflict of Interest Statement

Declarations. Ethics approval and consent to participate: All the samples were collected by authorized personnel at the animal hospital, and an ethical permit (no. 5.8.18–15528/2021) was obtained from the Swedish Board of Agriculture, Uppsala regional ethical committee on animal experiments before any samples were collected. Informed consent was obtained from the animal owners prior to sampling. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

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