Morphometric parameters, metabolic profile and musculoskeletal alterations in Criollo horses competing in the morphology trial.

Research Overview

• This study examined the physical characteristics, metabolic health, hoof structure, and joint health of Criollo horses competing in morphological events, with a focus on how body fat and sex differences relate to these traits.
• It identified links between overweight conditions, hoof morphology, and degenerative joint changes, emphasizing potential risks for musculoskeletal problems in these horses.

Objectives of the Study

• Assess morphometric traits, metabolic profiles, hoof morphology, and tarsal joint alterations in Criollo horses participating in morphological trials.
• Evaluate differences between male and female horses regarding these parameters.
• Investigate associations between morphometric measurements, hoof structure, and the severity of osteoarthritis in tarsal joints.

Methods

• Sample: 55 Criollo horses (30 mares, 25 stallions) involved in morphology competitions.
• Physical evaluation included:
  • Body condition score (BCS), a numerical indicator of body fat and overall condition.
  • Cresty neck score (CNS) to evaluate neck fat deposition.
  • Various morphometric measurements, including neck circumference and hoof dimensions.
• Metabolic assessments measured blood concentrations of:
  • Cholesterol and lipoproteins.
  • Leptin and adiponectin, hormones linked to fat regulation and metabolism.
  • Muscle enzymes indicating metabolic or muscular status.
• Radiographic examinations:
  • Forelimb hooves (49 horses) to analyze hoof morphology.
  • Tarsal joints (48 horses) to detect degenerative changes (osteoarthritis lesions).

Key Findings

• High prevalence of overweight horses: Many Criollos scored BCS ≥7, indicating excess body fat.
• Sex differences found:
  • Males had significantly larger neck circumference than females (p < 0.05).
  • Females had higher overall body fat percentage (p < 0.05).
  • Males exhibited longer second phalanx bones (P2) in the hooves (p < 0.05).
• Associations between adiposity and hoof morphology:
  • Positive correlation between distal phalanx descent and both body fat and tailhead fat (r=0.31, P=0.01), suggesting that higher fat is related to hoof bone positional changes.
  • Distal lamellar zone distance, a measure of hoof laminae structure, was positively associated with body and tailhead fat (r=0.34, P=0.009).
  • Hoof angle negatively correlated with neck fat (r=-0.41, P=0.02), indicating that increased neck fat may be linked to changes in hoof conformation.
• Tarsal joint degeneration:
  • All horses showed radiographic signs of tarsal joint lesions, indicating widespread joint degeneration.
  • Females had higher lesion scores than males (p = 0.005), suggesting more severe joint changes.

Conclusions and Implications

• Overweight conditions are common in Criollo horses competing in morphological trials, likely due to intensive management practices favoring early fat accumulation.
• The study revealed important sex-related differences in fat distribution, hoof structure, and joint health.
• Correlations between adiposity measures and hoof morphology suggest that excess body fat may contribute to hoof alterations, which are a known risk factor for laminitis (a painful inflammation of the hoof).
• Widespread tarsal osteoarthritis highlights a musculoskeletal health concern in this horse population, possibly worsened by increased body condition.
• Results underscore the need to consider body condition and metabolic health in managing horses for morphological competitions to prevent orthopedic problems and preserve performance and welfare.