A comparison of traditional and quantitative analysis of acid-base and electrolyte imbalances in horses with gastrointestinal disorders.
Authors: Navarro Marga, Monreal Luis, Segura Dídac, Armengou Lara, Añor Sònia
Journal: Journal of veterinary internal medicine
Summary
When horses present with acute colic, the underlying acid-base and electrolyte disturbances can be subtle and easily overlooked using conventional blood gas analysis alone. Researchers compared traditional diagnostic approaches with quantitative (Stewart) methods across 115 colic cases stratified by pathology type (obstructive, ischaemic, inflammatory, and diarrheic) and 45 healthy controls, measuring standard parameters alongside strong ion difference, nonvolatile weak buffers, and strong ion gap. Whilst pH remained relatively preserved across all colic groups, the quantitative approach revealed substantially higher rates of metabolic imbalance—notably 78% of diarrheic cases showed strong ion acidosis masked by concurrent nonvolatile buffer alkalosis—compared to conventional interpretation which detected abnormalities in only 22% of this group. All colic horses demonstrated statistically significant hypocalcaemia, and diarrheic cases additionally exhibited hyponatraemia, hypokalaemia, and hypoproteinaemia alongside reduced strong ion difference. For practitioners managing colic cases, particularly those with concurrent hypoproteinaemia or electrolyte abnormalities, adopting quantitative acid-base analysis provides superior diagnostic sensitivity and more rational guidance for targeted fluid and electrolyte therapy than traditional methods alone.
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Practical Takeaways
- •Traditional acid-base analysis can miss important metabolic disturbances in colic horses—quantitative approaches should be used when strong ion imbalances and low plasma protein are present to guide more accurate treatment decisions
- •All colic types involve electrolyte changes requiring supplementation; pay particular attention to calcium, potassium, and magnesium losses in diarrheic cases
- •Even when blood pH appears normal on routine testing, significant acid-base disturbances may be present and require quantitative analysis for proper clinical management
Key Findings
- •All colic horses showed statistically significant decreases in ionized calcium concentration despite normal pH in most cases
- •Quantitative analysis revealed metabolic imbalances in 78% of diarrheic horses compared to only 22% detected by traditional analysis, primarily strong ion acidosis with nonvolatile buffer alkalosis
- •Ischemic colic (74%) and inflammatory colic (87%) showed higher rates of metabolic imbalance by traditional analysis compared to obstructive (26%) and diarrheic (22%) groups
- •Diarrheic colic group demonstrated significant decreases in sodium, total calcium, magnesium, total protein, albumin, and strong ion difference