Researchers have established baseline reference intervals for symmetric dimethylarginine (SDMA) in clinically healthy Lacaune sheep, providing clinical thresholds for a renal biomarker that demonstrates higher sensitivity than traditional markers in detecting severe kidney damage. In a cohort of 143 healthy animals, serum SDMA concentrations established an overall reference interval of 0.59 to 1.72 µmol/l, filling a critical diagnostic gap where species-specific ovine values were previously undocumented.
The study sought to resolve key limitations linked to conventional renal monitoring tools, specifically serum creatinine and urea. Because traditional indicators depend heavily on dietary protein intake and muscle mass, they frequently fail to detect early renal dysfunction, especially in emaciated livestock. While SDMA had previously shown promise in other species for earlier and more sensitive kidney disease detection, baseline reference intervals in ovine species had remained undocumented.
To establish standardized values, investigators evaluated a reference population of 143 healthy Lacaune sheep selected on the basis of clinical health, body condition scores, and baseline serum creatinine concentrations. The study population was stratified by age into juvenile sheep under one year of age and adult sheep aged one year or older. Serum SDMA concentrations were quantified using an enzyme-linked immunosorbent assay (ELISA) previously validated for canine and feline patients.
Analysis of the healthy cohort yielded an adult reference interval of 0.59 to 1.56 µmol/l and a juvenile interval of 0.59 to 1.83 µmol/l. Juvenile sheep exhibited significantly higher SDMA concentrations than adults (p < 0.001), establishing age-related variation in ovine baselines. In contrast to the age-related distinctions, the researchers identified no significant differences in SDMA levels between male and female sheep.
The clinical utility of the biomarker was assessed through a retrospective analysis of 51 deceased sheep that had undergone histopathological renal examinations. Serum SDMA was significantly elevated in animals with severe renal lesions compared to those displaying no, mild, or moderate lesions (p = 0.005), whereas serum creatinine showed no statistically significant differences across lesion severities. Notably, SDMA successfully identified severe renal lesions in animals with poor body condition whose creatinine levels remained within or below normal reference intervals. While the authors identified the economic feasibility of testing as an ongoing limitation, the established intervals provide a foundation for clinical application and early renal diagnosis in sheep.
Subject of Research: Reference intervals and diagnostic utility of symmetric dimethylarginine in Lacaune sheep
Article Title: Determination of reference intervals for symmetric dimethylarginine (SDMA) in Lacaune sheep
Article References: Kiene, F., Wagener, M. G., Röhrig, P., & Ganter, M. (2026). Determination of reference intervals for symmetric dimethylarginine (SDMA) in Lacaune sheep. BMC Veterinary Research, 22(1), Article 670. https://doi.org/10.1186/s12917-026-06074-7
Image Credits: AI Generated
DOI: 10.1186/s12917-026-06074-7
Keywords: symmetric dimethylarginine, SDMA, Lacaune sheep, renal biomarkers, reference intervals, veterinary nephrology, creatinine, ovine medicine, Determination, reference, intervals, symmetric
News Source: Drew Townsend. (November 8, 2026). Reference Intervals Established for Kidney Biomarker SDMA in Lacaune Sheep. Scienmag.
