PSI-9 Efficacy of Electrolyte Chews in Horses

Abstract

Oral supplementation with electrolytes is commonly practiced among horse owners. However, practical ease of administration can be challenging due to palatability issues. The objective of this study was to investigate the efficacy of a novel electrolyte product form during routine exercise. Protocol approval (21-029) by Southern Illinois University Institutional Animal Care and Use Committee was obtained before initiation of this work. Privately-owned local foxhunting horses (n = 15) were evaluated. Treatment groups were identified based on voluntary consumption of chews and include control (CON) = 0 chews; light (LIG) 6 to 9 chews; and moderate (MOD) 15 to 20 chews. Jugular venipuncture and vitals assessments were completed 30 minutes before and 30 minutes following a 2-hour ride. Electrolyte chews were offered in two sessions: 30 minutes pre-ride and immediately post-ride. Serology values for Na, K, Cl, Ca, HCO⁻₃, Mg were measured as well as respiratory rate (RR), skin turgor (SKN), and rectal temperature (BT). Categorical variables included body condition score (BCS), sex, and breed (BRD). Data were analyzed via PROC GLM, PROC FREQ and PROC CORR dependent on test with SAS (v. 9.5). Significance for all tests was set at P < 0.05. Serological values were unaffected by electrolyte consumption (P > 0.05). Body temperature was significantly higher for all horses following exercise, regardless of treatment group (P = 0.0005). Skin turgor showed significantly more time before return to original state during post-ride evaluation (P = 0.0013). Respiratory rate was noted to decrease post-exercise, suggesting an increased baseline due to recent transport (P = 0.0158). Directional serum changes between Cl and K were correlated (P = 0.0227) as well as Mg and Cl (P = 0.0316). Correlations of relational change between Ca and HCO⁻₃ in addition to Ca and Na were approaching significance (P = 0.0707; P = 0.0800). Mares demonstrated a greater ability to maintain lower post-ride serum calcium levels than geldings (P = 0.013). Preliminary effect of breed on serological calcium change may also be considered (P = 0.0312). To conclude, differences in sex may alter electrolyte use pathways, such as calcium. The exercise challenge was sufficient based on vitals assessments. These data suggest key factors associated with chewable electrolyte form administration. Further research is needed to identify the impacts of electrolyte form on efficacy as well as improve palatability.