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GeroScience2025; doi: 10.1007/s11357-025-01738-y

Indicators of mortality risk in ageing horses.

Abstract: Clinical care for patients with limited life expectancy often requires adjustments, prioritizing immediate benefits over long-term outcomes, as the relevance of future complications diminishes. This study identifies indicators of mortality risk in horses with chronic orthopaedic conditions to enhance individualized care and welfare. Over 3 years, 123 chronically lame horses and 6 healthy control horses at an animal sanctuary underwent regular (every 3 months) comprehensive health assessments and activity monitoring using wearable sensors. Data collected included body condition scores, musculoskeletal pain scores, lameness evaluations, and time budgets for eating, resting, and activity. Of the 123 chronically lame horses, 31 horses died (n = 31/123, 25.2%), with 10 succumbing to acute decompensation of their chronic condition (DAC, n = 10/123, 8.1%), while 21 were euthanized due to intractable pain or progressively deteriorating health and function (DCC, n = 21/123, 17.1%). Statistical modelling using death as outcome measure revealed body condition, pain scores, and time budget data to be strongly associated with equine mortality. Notably, low body condition score and reduced eating time predicted mortality in DAC horses, aligning with human studies linking weight loss to frailty and increased mortality risk. Additionally, depression-like behaviours were prevalent in DAC horses, mirroring the link between depression and mortality in humans. While pain scores were elevated in all deceased horses, weight loss was specific to DAC, suggesting multifactorial influences beyond pain. These findings provide a foundation for developing equine-specific tools to predict outcomes and guide clinical and end-of-life decisions, enabling individualized treatment to enhance the welfare and quality of life for aging horses. These insights may also offer valuable information for human medicine, particularly for at-risk groups such as individuals with cognitive impairments who may struggle to communicate their symptoms.
Publication Date: 2025-06-25 PubMed ID: 40555923PubMed Central: 9817422DOI: 10.1007/s11357-025-01738-yGoogle Scholar: Lookup
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Summary

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The paper examines indicators of mortality risk in ageing horses suffering from chronic orthopaedic conditions. The researchers discovered that body condition, pain scores, and certain behavioral data could be utilized to predict the likelihood of equine mortality.

Study Details and Methodology

  • This study monitored 123 chronically lame horses and 6 healthy control horses over a period of 3 years. Every quarter, each horse underwent a comprehensive health assessment and was monitored using wearable sensors.
  • Data collected included body condition scores, musculoskeletal pain scores, lameness evaluations, and time spent eating, resting, and engaging in activity.
  • Out of the 123 chronically lame horses, 31 died (equivalent to 25.2% of the total sample), with different ailments causing the deaths. 10 horses experienced acute degradation of their chronic condition (DAC), while 21 deteriorated progressively and were euthanized due to unmanageable pain or declining health and function (DCC).

Findings and Discoveries

  • Statistical modelling demonstrated a strong correlation between equine mortality and various factors including body condition, pain scores, and time allocated to different activities.
  • In particular, horses with low body condition scores and less eating time were more likely to die due to DAC. This is in line with human studies suggesting an increased risk of mortality due to weight loss and frailty.
  • Depression-like behaviors were prevalent in DAC horses, reflecting similar connections between depression and mortality in human subjects.
  • All deceased horses had high pain scores, but weight loss was found to be exclusively associated with DAC cases. This indicates the presence of several contributing factors beyond pain.

Implications and Applications

  • The results of this study could inform the development of tools to predict outcomes and navigate clinical and end-of-life decisions for horses, facilitating personalized treatment and thereby improving animal welfare and quality of life for ageing horses.
  • Depressed mood and musculoskeletal pain being indicators of mortality risk resonates with findings in human medicine. Therefore, the findings could also be potentially relevant in human contexts, especially for susceptible population groups, such as those with cognitive impairments who have difficulty expressing their symptoms.

Cite This Article

APA
Kelemen Z, Vogl C, Torres Borda L, Auer U, Jenner F. (2025). Indicators of mortality risk in ageing horses. Geroscience. https://doi.org/10.1007/s11357-025-01738-y

Publication

ISSN: 2509-2723
NlmUniqueID: 101686284
Country: Switzerland
Language: English

Researcher Affiliations

Kelemen, Z
  • Equine Surgery Unit, Centre for Equine Health and Research, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria.
Vogl, C
  • Department for Biological Sciences and Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
Torres Borda, L
  • Equine Surgery Unit, Centre for Equine Health and Research, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria.
Auer, U
  • Anaesthesia Unit, Centre for Small Animal Health and Research, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria.
Jenner, F
  • Equine Surgery Unit, Centre for Equine Health and Research, Department for Small Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria. florien.jenner@vetmeduni.ac.at.

Conflict of Interest Statement

Declarations. Ethics approval: This study was purely observational in nature and entailed only monitoring the horses under their current conditions of life. No experimental procedures, invasive interventions, or alterations to routine care were performed, and no specific veterinary treatments or interventions were carried out for the purpose of this study. The study protocol was submitted to the Institutional Ethics Committee of the University of Veterinary Medicine Vienna, which determined that formal ethical approval was not required and issued a waiver (ETK-152/09/2019) in accordance with the “Good Scientific Practice. Ethics in Science and Research” guidelines implemented at the University of Veterinary Medicine Vienna and national legislation. All methods were carried out in accordance with relevant guidelines and regulations. Competing interests: The authors declare no competing interests.

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