Serum symmetric dimethylarginine concentration in healthy horses and horses with acute kidney injury.
Authors: Siwinska Natalia, Zak Agnieszka, Slowikowska Malwina, Niedzwiedz Artur, Paslawska Urszula
Journal: BMC veterinary research
Summary
# Editorial Summary: Symmetric Dimethylarginine as an Early Marker for Equine Acute Kidney Injury Acute kidney injury in horses presents a diagnostic challenge, with current detection methods relying on creatinine and urea—markers that may not elevate until significant renal damage has already occurred. Researchers measured serum symmetric dimethylarginine (SDMA), a metabolite that precedes conventional markers of renal dysfunction, in 53 healthy horses (including 17 foals and 36 adults) and 23 horses with confirmed AKI, using a commercial ELISA assay alongside conventional blood work and ultrasonographic evaluation of the urinary tract. Horses with AKI demonstrated significantly elevated SDMA concentrations compared to healthy animals, and the marker showed age-dependent variation in the healthy population—an important consideration for establishing clinically relevant reference ranges in different age groups. SDMA concentration correlated with serum creatinine and urea levels but appeared to rise earlier in the disease process, suggesting potential value as an earlier diagnostic indicator. For equine practitioners, SDMA testing may offer a more sensitive window for detecting subclinical or early-stage kidney injury before traditional markers become elevated, enabling earlier intervention; however, establishing robust species-specific reference intervals across different age groups remains essential before incorporating this marker into routine clinical protocols.
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Practical Takeaways
- •SDMA appears to be a promising diagnostic tool for detecting acute kidney injury in horses when traditional markers (creatinine, urea) may still be normal
- •Reference ranges for healthy horses need to be established accounting for age and body weight differences, as these factors influence SDMA concentrations
- •Consider SDMA testing as part of diagnostic workup for suspected AKI, particularly in foals and young horses where early detection is critical
Key Findings
- •Serum SDMA concentrations were measurable in healthy horses (foals and adults) using commercial ELISA, establishing baseline reference values
- •SDMA concentrations were elevated in horses with acute kidney injury compared to healthy controls
- •Age, sex, and body weight showed associations with serum SDMA levels in healthy horses
- •SDMA may serve as an earlier or more sensitive marker of kidney dysfunction than traditional creatinine and urea measurements