Correlation between l‐lactate and glucose concentrations and body condition score in healthy horses and ponies

BACKGROUND: Blood l‐lactate and glucose concentrations were higher in ponies with gastrointestinal disease than in horses, possibly because of differences in body condition (BC). OBJECTIVES: To investigate whether l‐lactate and glucose concentrations correlate with BC and differ between healthy horses and ponies. ANIMALS: Systemically healthy client‐owned ponies (n = 101) and horses (n = 51). METHODS: Prospective observational study. Breed, weight, height, and subjective and objective measures of BC were recorded and l‐lactate and glucose concentrations were measured. Correlations between l‐lactate and glucose concentrations and BC were established. The association between l‐lactate concentrations, equid type (pony or horse), BC, age, and glucose concentrations was investigated using a multivariable model. RESULTS: Weak but significant (P = .001) negative correlations were detected between l‐lactate concentration and average BC score (r = −0.29), heart girth:height ratio (r = −0.27), and age (r = −0.27). Glucose concentrations were significantly (P < .001) positively correlated with neck length:heart girth ratio (r = 0.37) and heart girth:height ratio (r = 0.31). l‐lactate and glucose concentrations were weakly correlated (r = 0.15; P = .04). In the final multivariable model, age (−0.02 ± 0.006; P = .001) and heart girth:height ratio (−1.74 ± 0.53; P = .001) were significantly associated with the natural logarithm of l‐lactate concentration (Lnl‐Lactate). This represents a 2% decrease in l‐lactate concentration per year increase in age and 10% decrease in l‐lactate concentration per 0.06 unit increase in heart girth:height ratio. CONCLUSIONS AND CLINICAL IMPORTANCE: In healthy horses and ponies, age and BC significantly influence l‐lactate concentrations.