Endocrine, morphometric, and ultrasonographic characterization of neck adiposity in Andalusian horses.

The research article focuses on finding easier ways to identify horses that are affected by or are at risk for equine metabolic syndrome (EMS), a common condition characterized by obesity and insulin resistance. The study examines the relationship between hormonal markers of obesity (leptin) and insulin resistance (insulin), with morphometric (measurable physical quantities) and ultrasonographic measurements of neck fat in Andalusian horses. The results suggest that subcutaneous fat thickness at the base of the neck can potentially predict EMS.

Study Objective and Methods

• The objective of the research was to find easier ways to predict EMS in horses by investigating the relationship between hormonal markers, leptin and insulin, and physical measurements of neck adiposity (fat).
• The plasma leptin and insulin concentrations were measured in 127 Andalusian horses using a Radioimmunoassay (RIA).
• The researchers measured the neck circumferences of the horses at 25%, 50%, and 75% of their neck length, and at the same points, used ultrasound to measure the thickness of subcutaneous fat (the fat beneath the skin).

Results and Findings

• The study confirmed a tendency towards adiposity (obesity) in the studied horse population, indicated by elevated plasma leptin levels, but the plasma insulin concentrations were generally within normal range.
• The researchers found that neck circumference showed significant sexual dimorphism (differences between males and females) but did not correlate well with the hormonal measurements.
• In contrast, the ultrasonographic assessment of fat thickness at the base of the neck was significantly correlated with both plasma leptin and insulin levels, and did not show differences between males and females.

Conclusion and Implications

• The results suggest that the measurement of subcutaneous fat thickness at the base of the neck (SFT-75%) could potentially serve as a predictor for EMS.
• This finding may provide a simple and feasible way to assess the risk for EMS in large populations of horses by measuring a single parameter rather than undertaking extensive hormonal testing.