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Frontiers in veterinary science2025; 12; 1545577; doi: 10.3389/fvets.2025.1545577

Investigating the interplay of stressors and health in horses through fecal cortisol metabolite analysis.

Abstract: Horses are highly sensitive to stress, which can affect their wellbeing and lead to various health issues. Effective and objective stress assessment is therefore crucial for improving their care and management. The production of the glucocorticoid cortisol is increased in response to stressful stimuli and its metabolites can be measured non-invasively in feces. Therefore, this study aimed to explore the impact of different environmental and physiological stressors on fecal cortisol metabolite (FCM) concentrations in horses, with a particular focus on the relationship between stress, health, and welfare. We hypothesized that increased FCM levels may be indicative of disease and thus improve early detection and subsequent intervention. Unassigned: Fresh fecal samples of = 41 horses (20 geldings and 21 mares) from the same herd were collected once weekly for 1 year. Horses had been housed in the same stable for at least a month and were accustomed to the habitat, daily routine, and social groups. Environmental conditions, health data, and potentially stressful events were recorded. Fecal concentrations of 11,17-dioxoandrostanes were measured via 11-oxoetiocholanolone enzyme immunoassay. Unassigned: We showed stable baseline FCM concentrations of 6.3 ng/g feces (range 0.6-28.1 ng/g feces). During the summer months, median FCM concentrations increased significantly ( < 0.05; One Way RM ANOVA), and this increase correlated with higher ambient temperatures ( < 0.0001, = 0.669, Pearson Product Moment correlation). Additionally, other factors such as breed, coat color, and housing conditions influenced the FCM concentrations. Stressful events, such as riding exams and some painful conditions, also resulted in elevated FCM levels, although the magnitude of these responses varied across individual horses. However, not all diseases were associated with increased FCMs. Unassigned: Our findings emphasize the complexity of the hypothalamic-pituitary-adrenal axis in horses, suggesting that while high FCM levels can indicate stress, they may not be reliable biomarkers for early disease detection. Particularly in the light of climate change, the impact of heat stress in the summer months should not be neglected and measures to improve the housing conditions accordingly should become an essential part of equine health management.
Copyright © 2025 Nowak, Macho-Maschler, Biermann, Palme and Dengler.
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Publication Date: 2025-04-08 PubMed ID: 40264993PubMed Central: PMC12013657DOI: 10.3389/fvets.2025.1545577Google 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.

This research article showed that fecal cortisol metabolite (FCM) concentrations in horses can reflect their stress levels and is influenced by variables like surrounding environmental conditions and health status. However, the study also found that while high FCM values can signal stress, they may not serve as dependable early markers for disease detection.

Research Objective and Process

  • The research primarily aimed to assess the impact of various environmental and physiological stressors on FCM concentrations in horses.
  • The focus was on the interaction between stress, health, and welfare.
  • The researchers hypothesized that increased FCM levels might indicate disease, thereby aiding in early detection and intervention.
  • Fecal samples from 41 horses were collected once weekly for a year with consistent environmental conditions and a familiar daily routine.
  • Recordings were made of possibly stressful events, health data, and environmental conditions.
  • The study then measured fecal concentrations of 11,17-dioxoandrostanes through an 11-oxoetiocholanolone enzyme immunoassay.

Findings of the Study

  • Baseline FCM concentrations were stable, and a significant increase was observed during summer months, which correlated with higher ambient temperatures.
  • FCM concentrations were found to be influenced by certain factors such as the breed of the horse, the color of its coat, and conditions of the housing.
  • Elevated FCM levels were seen during stressful events like riding exams and some painful conditions. However, the increase varied among individual horses.
  • The research found that increased FCMs were not linked with all diseases.

Implications of the Research

  • The study demonstrated the complexity of the hypothalamic-pituitary-adrenal (HPA) axis in horses.
  • It suggested that even though high FCM levels may indicate stress, they might not act as reliable biomarkers for early disease detection.
  • The research emphasized the importance of assessing climate change’s impact on heat stress during summer months.
  • The study advised that improving housing conditions should be integral to managing equine health, particularly considering climate change and heat stress.

Cite This Article

APA
Nowak AC, Macho-Maschler S, Biermann NM, Palme R, Dengler F. (2025). Investigating the interplay of stressors and health in horses through fecal cortisol metabolite analysis. Front Vet Sci, 12, 1545577. https://doi.org/10.3389/fvets.2025.1545577

Publication

Frontiers in veterinary science
ISSN: 2297-1769
NlmUniqueID: 101666658
Country: Switzerland
Language: English
Volume: 12
Pages: 1545577
PII: 1545577

Researcher Affiliations

Nowak, Aurelia C
  • Department of Biological Sciences and Pathobiology, Institute of Physiology and Pathophysiology, University of Veterinary Medicine Vienna, Vienna, Austria.
Macho-Maschler, Sabine
  • Department of Biological Sciences and Pathobiology, Experimental Endocrinology, University of Veterinary Medicine Vienna, Vienna, Austria.
Biermann, Nora M
  • Department of Small Animals and Horses, Clinical Unit of Equine Surgery, University of Veterinary Medicine Vienna, Vienna, Austria.
Palme, Rupert
  • Department of Biological Sciences and Pathobiology, Experimental Endocrinology, University of Veterinary Medicine Vienna, Vienna, Austria.
Dengler, Franziska
  • Department of Biological Sciences and Pathobiology, Institute of Physiology and Pathophysiology, University of Veterinary Medicine Vienna, Vienna, Austria.
  • Department of Livestock Tissue Metabolism, Institute of Animal Science, University of Hohenheim, Stuttgart, Germany.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Citations

This article has been cited 2 times.
  1. Fialová S, Kuřitková D, Sobotková E. Stress Responses in Dressage Horses: Insights from FEI Noseband Measurements Across National Competition Levels. Animals (Basel) 2026 Feb 6;16(3).
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  2. Krieber J, Nowak AC, Geissberger J, Illichmann O, Macho-Maschler S, Palme R, Dengler F. Fecal Cortisol Metabolites Indicate Increased Stress Levels in Horses During Breaking-In: A Pilot Study. Animals (Basel) 2025 Jun 7;15(12).
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