SDMA: An Early and Reliable Biomarker in Veterinary Diagnostics for Kidney Health

Kidney health is a cornerstone of patient well-being, supporting essential physiological processes such as blood pressure regulation, erythropoiesis, hormonal balance, and waste elimination. Detecting renal dysfunction early is critical, as timely diagnosis and intervention can significantly slow disease progression and improve clinical outcomes. Within veterinary diagnostics, symmetric dimethylarginine (SDMA) has emerged as a highly sensitive and reliable biomarker of kidney function, complementing traditional markers such as creatinine and BUN.

Why SDMA is Important

SDMA directly reflects changes in glomerular filtration rate (GFR). Unlike creatinine—which typically increases only after 75% of renal function is lost—SDMA rises with as little as 25–40% loss. This earlier detection enables clinicians to identify renal compromise sooner, even in clinically normal patients, providing a diagnostic advantage in both health screening and disease investigation.

Creatinine levels also increases due to other factors like muscle loss while SDMA remains unaffected.

Diagnostic Interpretation of SDMA

< 15 µg/dL – Within normal limits, consistent with healthy renal function

15–19 µg/dL – Mildly elevated

≥ 20 µg/dL – Probable kidney disease

Other Diagnostic Scenarios for SDMA Testing

While beneficial for most patients, SDMA is especially advantageous in:

1. Wellness screening – Creating baselines for the early identification of kidney issues.

2. Cats with hyperthyroidism – Where coexisting kidney disease is prevalent and often missed.

3. Pre-anesthetic evaluation – To identify at-risk patients and aid in safe anesthetic planning.

4. Infectious/vector-borne disease cases – To evaluate the long-term effects on the kidneys and inform management.

5. Medical presentations – Facilitating early detection and monitoring of kidney involvement in complex cases.

Conclusion

In veterinary diagnostics, SDMA represents a significant advancement by enabling earlier and more accurate detection of renal dysfunction compared to creatinine. Its inclusion in routine laboratory testing provides veterinarians with a powerful tool for proactive diagnosis, informed decision-making, and improved patient outcomes.

Supporting Diagnostics for Kidney Health in Dogs and Cats

Test	Role in Kidney Diagnostics
SDMA	Early biomarker of reduced GFR; increases with as little as 25–40% loss of kidney function, earlier than creatinine.
Creatinine	Traditional renal marker; rises only after ~75% function loss, useful for staging and monitoring.
Phosphorus	Elevated levels reflect impaired excretion and disease progression, especially in chronic kidney disease (CKD).
Urine Protein:Creatinine Ratio (UPC)	Detects and quantifies proteinuria, a marker of glomerular injury and an important prognostic indicator.
Complete Urinalysis	Evaluates urine sediment, pH, and abnormalities; identifies infection, inflammation, or urinary tract pathology.
Urine Specific Gravity (USG)	Measures concentrating ability; helps differentiate pre-renal, renal, and post-renal azotemia.

Together, these tests complement each other to deliver a robust, accurate assessment of kidney health, enabling earlier detection, better disease staging, and informed clinical decisions.

Several companies have recently introduced SDMA dry test kits in the veterinary market, making kidney health diagnostics more accessible and convenient.