Salivary alpha-amylase activity and concentration in horses with acute abdominal disease: Association with outcome.
Authors: Contreras-Aguilar M D, Martínez-Subiela S, Cerón J J, Martín-Cuervo M, Tecles F, Escribano D
Journal: Equine veterinary journal
Summary
# Salivary alpha-amylase as a prognostic indicator in equine colic Researchers investigated whether salivary alpha-amylase (sAA) could serve as an objective biomarker of disease severity and survival outcome in horses presenting with acute abdominal disease, comparing 33 affected horses against 25 healthy controls using both colorimetric activity assays and immunofluorometric concentration measurements. Diseased horses demonstrated dramatically elevated sAA activity (median 29.8 IU/L versus 4.3 IU/L in controls) and concentration (388.3 ng/mL versus 58.4 ng/mL), with non-surviving horses showing substantially higher activity levels (479.0 IU/L) than survivors (19.3 IU/L). sAA activity correlated moderately with heart rate (r = 0.66) and plasma lactate (r = 0.57), weakly with salivary cortisol and systemic inflammatory response syndrome scores, and emerged as an independent predictor of mortality risk. For equine practitioners, sAA activity—though not concentration alone—offers potential clinical value as a prognostic aid in acute abdominal cases, particularly when interpreted alongside traditional markers of systemic stress and tissue hypoperfusion, though the relatively small sample size warrants cautious application until findings are validated in larger cohorts. Further investigation should incorporate pain assessment data to establish whether sAA changes reflect acute stress response pathways distinct from mechanical colonic disease.
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Practical Takeaways
- •Salivary alpha-amylase activity measured via simple colorimetric assay may serve as a rapid, non-invasive prognostic indicator for horses presenting with acute abdominal disease
- •Markedly elevated sAA activity in a horse with colic should raise concern for poor prognosis and may help guide clinical decision-making regarding intensive treatment or referral
- •This biomarker correlates with conventional severity markers (heart rate, lactate) but offers the advantage of being measurable from saliva without blood sampling
Key Findings
- •Salivary alpha-amylase (sAA) activity was significantly elevated in horses with acute abdominal disease (median 29.8 IU/L) compared to healthy controls (median 4.3 IU/L, P<0.001)
- •Non-surviving horses had markedly higher sAA activity (median 479.0 IU/L) than survivors (median 19.3 IU/L, P<0.001)
- •sAA activity correlated moderately with heart rate (r=0.66) and plasma lactate concentration (r=0.57), both indicators of disease severity
- •sAA activity, but not concentration, was significantly associated with increased risk of non-survival (P=0.01)