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

Abstract 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 (Ln l ‐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.