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Home / Equine Research Bank / Vet Sci / Alterations in the Microbiome of Horses Affected with Fecal ...
Veterinary sciences2025; 12(8); 724; doi: 10.3390/vetsci12080724

Alterations in the Microbiome of Horses Affected with Fecal Water Syndrome.

Abstract: Fecal water syndrome (FWS) in horses is characterized by two-phase defecation, including both solid and liquid phases. While satisfactory explanations for FWS are unavailable, bacterial dysbiosis has been suggested as a contributing or causative factor. The objectives of this study were to determine whether fecal bacterial dysbiosis is associated with FWS in horses in the midwestern USA. Fecal samples were collected from horses with FWS and from unaffected horses at the same location. In total, 16S rRNA amplicon libraries produced from fecal bacterial DNA were sequenced using the Illumina sequencing platform. Significant differences in beta diversity were detected between affected and control horses ( = 7 × 10, F = 1.51), and differential abundance testing identified several features enriched in affected and control horses. These results agree with prior work regarding specific features in the bacterial microbiome associated with FWS, including spp., and suggest fecal dysbiosis is associated with FWS.
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Publication Date: 2025-07-31 PubMed ID: 40872676PubMed Central: PMC12390410DOI: 10.3390/vetsci12080724Google 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.

Alterations in the bacterial communities of feces are associated with fecal water syndrome (FWS) in horses, indicating that changes in gut microbiota may contribute to the condition where horses experience abnormal watery defecation.

Background and Purpose

  • Fecal Water Syndrome (FWS) in horses leads to a two-phase defecation process featuring both solid stool and watery feces.
  • The exact cause of FWS is not well understood, but disruptions in the normal bacterial populations of the gut (bacterial dysbiosis) have been proposed as a possible factor.
  • The study aimed to investigate whether horses affected by FWS show differences in their fecal bacterial communities compared to unaffected horses, particularly in a population from the midwestern United States.

Methods

  • Samples were taken from two groups of horses: those diagnosed with FWS and unaffected control horses located at the same site to control for environmental factors.
  • Researchers extracted bacterial DNA from fecal samples.
  • 16S rRNA gene sequencing was performed using the Illumina sequencing platform to profile the bacterial communities present. The 16S rRNA gene is commonly used for identifying bacteria because it contains both conserved and variable regions allowing taxonomic classification.
  • Bioinformatic analyses including beta diversity (a measure of differences in bacterial community composition between samples) comparisons and differential abundance testing were conducted to identify bacteria that differed significantly between affected and control horses.

Key Findings

  • Statistical analysis revealed significant differences in beta diversity between horses with FWS and unaffected horses, indicating distinct overall fecal bacterial community structures.
  • Differential abundance testing highlighted specific bacterial taxa that were more common either in FWS-affected horses or in controls, suggesting particular bacteria might be associated with the presence or absence of FWS.
  • The findings were consistent with prior studies that also found specific bacterial features associated with FWS, including certain unnamed species (represented by spp.).

Implications

  • The association between fecal bacterial dysbiosis and FWS supports a hypothesis that gut microbiota imbalance may contribute to the pathogenesis of FWS in horses.
  • This opens avenues for potential therapeutic approaches targeting the microbiome, such as probiotics, prebiotics, or dietary modifications to restore microbial balance and alleviate symptoms.
  • Further research is needed to clarify causal relationships and determine whether correcting microbial imbalances can prevent or treat FWS effectively.

Summary

  • This research enhances understanding of the role of the gut microbiome in equine fecal water syndrome.
  • Using advanced sequencing techniques, the study demonstrates that horses with FWS have altered fecal bacterial populations compared to healthy horses.
  • The study provides evidence supporting the involvement of gut dysbiosis in FWS, an important insight for veterinary medicine and equine health management.

Cite This Article

APA
Porter MM, Davis DJ, McAdams ZL, Townsend KS, Martin LM, Wilhite C, Johnson PJ, Ericsson AC. (2025). Alterations in the Microbiome of Horses Affected with Fecal Water Syndrome. Vet Sci, 12(8), 724. https://doi.org/10.3390/vetsci12080724

Publication

Veterinary sciences
ISSN: 2306-7381
NlmUniqueID: 101680127
Country: Switzerland
Language: English
Volume: 12
Issue: 8
PII: 724

Researcher Affiliations

Porter, Madison M
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
Davis, Daniel J
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Animal Modeling Core, University of Missouri (MU), 4011 Discovery Drive, Columbia, MO 65201, USA.
McAdams, Zachary L
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Metagenomics Center (MUMC), University of Missouri, 4011 Discovery Drive, Columbia, MO 65201, USA.
Townsend, Kile S
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Department of Veterinary Medicine and Surgery, MU College of Veterinary Medicine, 900 E. Campus Drive, Columbia, MO 65211, USA.
Martin, Lynn M
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Department of Veterinary Medicine and Surgery, MU College of Veterinary Medicine, 900 E. Campus Drive, Columbia, MO 65211, USA.
Wilhite, Christopher
  • Wilhite and Frees, 21215 S. Peculiar Drive, P.O. Box 425, Peculiar, MO 64078, USA.
Johnson, Philip J
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Department of Veterinary Medicine and Surgery, MU College of Veterinary Medicine, 900 E. Campus Drive, Columbia, MO 65211, USA.
Ericsson, Aaron C
  • College of Veterinary Medicine (CVM), University of Missouri (MU), 1520 E. Rollins Drive, Columbia, MO 65211, USA.
  • Metagenomics Center (MUMC), University of Missouri, 4011 Discovery Drive, Columbia, MO 65201, USA.

Conflict of Interest Statement

The authors declare no conflicts of interest.

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