The aim of this study was to compare within-horse changes and between-horse differences in selected metabolic parameters for twenty cold-blooded mares, of which ten belonged to a group with a history of laminitis (LG) and ten formed the control group (CG). Measurements were conducted during four seasonal sampling periods in March (S0), May (S1), July (S2), and September (S3). Changes within individual horses over the season were determined using the coefficient of variation (CV) for each animal and differences between groups were evaluated using the t-test or Mann–Whitney test, depending on normality. LG showed a significantly higher insulin CV (LG 20.06% vs. CG 7.52%; p = 0.023). For fructosamines, the CV was higher in CG (26.61% vs. 20.09%; p = 0.0312), whereas glucose (p = 0.279) and body weight (p = 0.0576) showed no group differences. Variability between horse groups within samples was analyzed using the F-test. In S0, no differences were observed for glucose (p = 0.607) or insulin (p = 0.980), and fructosamines showed borderline significance (p = 0.05). Body weight variability was higher in LG (p = 0.010). In S1, greater dispersion in LG was found for fructosamines (p = 0.016) and insulin (p = 0.0329), while glucose (p = 0.952) and body weight (p = 0.0981) did not differ. In S2, LG showed markedly higher CV for glucose (p < 0.0001) and insulin (p = 0.0007), whereas fructosamines (p = 0.282) and body weight (p = 0.7418) remained comparable. In S3, no differences were detected for glucose (p = 0.512), fructosamines (p = 0.147) or insulin (p = 0.872), while body weight variability was again higher in LG (p = 0.0046). Overall, laminitic horses displayed greater seasonal fluctuations in metabolic parameters and, in several periods, more pronounced between-horse variability, suggesting a less stable metabolic response to seasonal conditions.
Thank you for your interesting abstract. I found your work very insightful.
Do you think that the increased seasonal variability in insulin observed in mares with a previous history of laminitis could reflect an underlying metabolic predisposition, such as insulin dysregulation or equine metabolic syndrome, even when clinical parameters remain within normal ranges?
Thank you in advance
Dr. Melina C. Crettaz Minaglia
Thank you for your interest in our work.
We believe that the increased seasonal variability in insulin concentrations observed in mares with a history of laminitis may indeed reflect the presence of an underlying metabolic predisposition, such as insulin dysregulation or equine metabolic syndrome. Importantly, this altered response may be present even when baseline clinical parameters remain within physiological reference ranges.
In our study, mares with a history of laminitis did not exhibit insulin concentrations exceeding physiological ranges; however, they showed markedly greater variability in response to seasonal changes in pasture composition. This suggests reduced stability of metabolic regulation and potentially increased sensitivity to the intake of non-structural carbohydrates.
These findings support the hypothesis that such individuals may exhibit a form of metabolic dysfunction that is not detectable through single time-point measurements. However, further studies with larger cohorts and more detailed endocrine profiling are needed to confirm this relationship and better understand its clinical relevance.
Thank you once again for your question.
Kind regards,
Stanislav Zaťko
