Blood amino acid changes associated with Lawsonia intracellularis infection in horses.
Authors: Mizuguchi Yuya, Niwa Hidekazu, Inoue Hiroki, Iwano Hidetomo
Journal: Equine veterinary journal
Summary
# Editorial Summary: Blood Amino Acid Changes in *Lawsonia intracellularis* Infection Whilst hypoproteinaemia and hypoalbuminaemia are well-recognised markers of equine proliferative enteropathy (EPE) caused by *Lawsonia intracellularis*, the broader disruption to amino acid metabolism in affected horses has remained largely unexplored until now. Mizuguchi and colleagues conducted a retrospective analysis of 135 serum samples from 59 farms, stratifying 135 horses into four groups: clinical EPE (n=46), subclinical EPE (n=22), exposed but unaffected animals (n=41), and unexposed controls (n=26), to characterise amino acid perturbations across the disease spectrum. Beyond shared alterations in asparagine, glutamine, aspartic acid, glutamic acid, and glycine across all infected and exposed groups, clinical EPE patients demonstrated characteristic depletion of alanine, citrulline, and tryptophan—findings with potential implications for muscle catabolism, immune function, and intestinal health. These results suggest that aminogram analysis could provide clinically relevant biomarkers for disease staging and potentially guide targeted nutritional or therapeutic interventions, though practitioners should note that farm-level variability inherent to the retrospective design may have influenced results. For nutritionists and clinicians managing *Lawsonia*-positive herds, these findings indicate that plasma amino acid profiling might help differentiate disease severity and inform more nuanced management strategies beyond conventional protein supplementation.
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Practical Takeaways
- •Blood amino acid profiles may provide a novel diagnostic marker for Lawsonia intracellularis infection status in horses, distinguishing clinical disease from subclinical exposure.
- •Specific amino acid perturbations (alanine, citrulline, tryptophan) could inform targeted nutritional interventions or therapeutic strategies in clinical EPE cases.
- •Consider aminogram analysis alongside traditional protein markers (albumin, total protein) when evaluating horses with suspected proliferative enteropathy.
Key Findings
- •Asparagine, glutamine, aspartic acid, glutamic acid, and glycine were significantly perturbed in clinical, subclinical, and exposure groups compared to controls.
- •Alanine, citrulline, and tryptophan were characteristically perturbed in clinical EPE horses relative to other groups.
- •Amino acid concentration perturbations correlate with clinical status of Lawsonia intracellularis infection.
- •Aminogram evaluation provides novel diagnostic and potentially therapeutic information for equine proliferative enteropathy.