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BMC veterinary research2025; 21(1); 596; doi: 10.1186/s12917-025-05032-z

Morphometric changes in overweight horses following 10-week weight loss programs.

Abstract: Up to 70% of horses in domestic equine populations are overweight. Promotion of weight loss is an important component of limiting the detrimental co-morbidities associated with excess adipose tissue. The use of a body condition score (BCS) can help equine caregivers track their horse's weight-status. However, this single score doesn't reflect changes in individual adipose depots. The purpose of this study was to characterize morphometric changes (including 8 anatomic BCS measurements that make up the whole-BCS) in horses during 3 different weight-loss programs over 10 weeks. Methods: Thirty-two horses were randomly assigned to one of three weight loss groups [exercise (E; fed to 100% digestible energy (DE) requirements, exercise 5x/week), feed restriction (FR; fed to 85% DE requirements, no exercise), or feed restriction and exercise (FRE; 85% DE, exercise 5x/week)], or a weight-maintained control (C; 100% DE, no exercise)] for 10 weeks. Horses were fed individualized diets formulated to meet their nutritional requirements. Outcome measures were recorded at weeks 1, 5 and 10, and included 11 morphometric measurements [body weight (BW) via weight tape, cresty neck score (CNS), and 8 individual BCSs (neck, shoulder, leg, withers, ribs, back, haunches, and tailhead) and a whole-BCS)]. Data were analyzed using a 2-Way RM ANOVA with respect to treatment group and week. Results: All 4 groups (including controls) had a significant reduction in BW and whole BCS. At week 10 whole BCS was lower in FRE than controls. All groups had a reduction in back, haunches, leg and shoulder; FR, FRE and E horses had reductions in rib BCS; E and FRE horses had reductions in tailhead BCS and CNS. Conclusions: In conclusion, all weight loss strategies produced significant weight loss, but only those strategies which included exercise reduced fat deposits known to be implicated in metabolic dysregulation in obese horses. Future studies should explore the optimum exercise load (duration and intensity) to facilitate loss of fat from these areas.
© 2025. The Author(s).
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Publication Date: 2025-10-10 PubMed ID: 41068901PubMed Central: PMC12512596DOI: 10.1186/s12917-025-05032-zGoogle 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.

Overview

  • This study investigated how different 10-week weight loss programs affect body fat distribution and morphometric measurements in overweight horses.
  • It found that exercise combined with feed restriction more effectively decreases fat in specific areas linked to metabolic problems compared to feed restriction alone or no intervention.

Background and Purpose

  • Up to 70% of domestic horses are overweight, which can lead to serious health issues related to excess fat.
  • Body Condition Score (BCS) is commonly used by caregivers to monitor overall fat but does not reflect changes in specific fat deposits on the body.
  • The study aimed to examine detailed morphometric changes, including eight regional BCS measurements (neck, shoulder, leg, withers, ribs, back, haunches, tailhead), during weight loss across different interventions.

Methods

  • Thirty-two horses were randomly assigned to one of four groups for 10 weeks:
    • Exercise only (E): fed at 100% digestible energy (DE) requirements, exercised 5 times per week.
    • Feed Restriction only (FR): fed at 85% DE requirements, no exercise.
    • Feed Restriction + Exercise (FRE): fed at 85% DE requirements, exercised 5 times per week.
    • Control (C): fed at 100% DE requirements, no exercise.
  • Diets were individually formulated to meet nutritional needs while controlling for energy intake.
  • Measurements were taken at weeks 1, 5, and 10, and included:
    • Body Weight (BW) via weight tape.
    • Cresty Neck Score (CNS) to assess fat accumulation in the neck area.
    • Eight individual BCS regions making up the whole-body BCS (neck, shoulder, leg, withers, ribs, back, haunches, tailhead).
    • Whole-body BCS score.
  • Data analysis used two-way repeated measures ANOVA considering treatment group and time to evaluate effects on morphometric measurements.

Results

  • All groups, including control animals, showed a significant decrease in body weight and whole-body BCS over the study period.
  • At the end of 10 weeks, whole-body BCS was significantly lower in the feed restriction + exercise (FRE) group compared to controls.
  • Specific fat depot changes:
    • All groups exhibited reductions in fat scores around the back, haunches, legs, and shoulders.
    • The FR, FRE, and E groups had reductions in the rib fat BCS, indicating fat loss in the rib area.
    • The E and FRE groups showed reductions in tailhead BCS and cresty neck score (CNS), areas associated with metabolic risk.

Conclusions and Implications

  • Multiple weight loss strategies can result in significant weight loss in overweight horses.
  • However, only those including exercise (E and FRE groups) effectively reduced fat deposits known to contribute to metabolic dysfunction, such as in the crest of the neck and tailhead regions.
  • This suggests exercise is crucial not just for weight loss but for targeting detrimental fat depots linked to health risks.
  • Future research should focus on determining the optimal exercise intensity and duration to maximize fat loss in these critical regions.
  • The study highlights the importance of assessing regional fat changes rather than relying solely on whole-body BCS to monitor health improvements during weight loss programs in horses.

Cite This Article

APA
Garland A, van Doorn DA, van den Boom R, Roelfsema E, Jung L, Boast M, Papadakis K, Margiotta M, Wafelbakker S, Briggs M, McCrae P, Pearson W. (2025). Morphometric changes in overweight horses following 10-week weight loss programs. BMC Vet Res, 21(1), 596. https://doi.org/10.1186/s12917-025-05032-z

Publication

BMC veterinary research
ISSN: 1746-6148
NlmUniqueID: 101249759
Country: England
Language: English
Volume: 21
Issue: 1
Pages: 596
PII: 596

Researcher Affiliations

Garland, Anna
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
van Doorn, David A
  • Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112, Utrecht, 3584 CM, The Netherlands.
  • Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112, Utrecht, 3584 CM, The Netherlands.
van den Boom, Robin
  • Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112, Utrecht, 3584 CM, The Netherlands.
Roelfsema, Ellen
  • Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112, Utrecht, 3584 CM, The Netherlands.
Jung, Lola
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Boast, Madeline
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Papadakis, Katerina
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Margiotta, Mary
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Wafelbakker, Samara
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Briggs, Morgan
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
McCrae, Persephone
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Pearson, Wendy
  • Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1, Canada. wpearson@uoguelph.ca.

MeSH Terms

  • Animals
  • Horses
  • Horse Diseases / therapy
  • Horse Diseases / diet therapy
  • Horse Diseases / pathology
  • Overweight / veterinary
  • Overweight / therapy
  • Overweight / diet therapy
  • Overweight / pathology
  • Physical Conditioning, Animal
  • Weight Loss / physiology
  • Male
  • Female
  • Body Composition

Grant Funding

  • RGPIN-2020-05823 / Natural Sciences and Engineering Research Council of Canada
  • RGPIN-2020-05823 / Natural Sciences and Engineering Research Council of Canada

Conflict of Interest Statement

Declarations. Ethics approval and consent to participate: All procedures were reviewed and approved by the University of Guelph’s Animal Care Committee (AUP #4436) in accordance with the guidelines of the Canadian Council on Animal Care. Consent for publication: Not Applicable. Competing interests: The authors declare no competing interests.

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