Next-generation reference-lab testing for kidney disease


Kidney disease is one of the most common conditions in older dogs and cats, with very serious health consequences. In time, one in three cats and one in ten dogs will develop some form of renal disease.

Identifying the disorder sooner gives you more time to intervene and find the best approach for each animal. Such early-stage diagnosis is now finally available to all vets through a revolutionary new kidney function test: IDEXX SDMA™.

Serum or plasma SDMA has been shown to be a more sensitive biomarker of renal function compared with creatinine. A persistent elevation in SDMA above 14 μg/dL would indicate reduced renal function. The use of IDEXX SDMA™ as part of the minimum data base permits the diagnosis of CKD prior to the onset of clinical signs and significant, often irreversible kidney damage.
What is IDEXX SDMA™?

Interpreting results

IDEXX SDMA™ is a new test to help evaluate kidney function. It increases earlier than creatinine in some animals with chronic kidney disease. Unlike creatinine, SDMA is not impacted by lean body mass. SDMA and Creatinine should be interpreted together, along with a urinalysis to properly assess kidney health. .





If both SDMA and creatinine are well within the reference interval, then kidney function is likely good. As SDMA and/or creatinine approach the upper end of the reference interval, early kidney disease cannot be ruled out. If SDMA is increased but creatinine is within the reference interval, then early kidney disease is likely. Alternatively, if the patient is poorly muscled, creatinine may be "falsely" decreased. Urine specific gravity should support some loss of urine concentrating ability. A complete urinalysis/UPC Ratio should be performed to evaluate for proteinuria and other evidence of kidney disease. If SDMA is within the reference interval and creatinine is increased, then kidney disease is possible. However, SDMA may be less impacted by dehydration than creatinine. Assess hydration status and urine specific gravity for evidence of dehydration or if there is loss of urine concentrating ability to support early kidney dysfunction. If both SDMA and creatinine are increased, then kidney function is likely impaired. Evaluate urine specific gravity to confirm loss of urine concentrating ability. A complete urinalysis and UPC Ratio should be performed to evaluate for proteinuria and other evidence of kidney disease.

The stages of Chronic Kidney Disease

  Stage 1 Stage 2 Stage 3 Stage 4
CLINICAL SIGNS None Subtle to mild
(E.G. PU/PD)
Or absent
Many extra-renal
clinical signs may
Be present
Increasing risk of
systemic clinical signs
and uremic crisis
SDMA Normal to 
mildly elevated
Mildly elevated 
to elevated
Elevated Elevated
UREA & CREA Nonazotemic Nonazotemic to 
mildly azotemic
Azotemic Azotemic
USG Normal Normal to 
mildly decreased
Decreased Decreased
Good to fair
Fair to poor
Fair to poor

IRIS - International Renal Interest Society

The mission of IRIS is to help veterinary Practitioners better diagnose, understand and treat kidney disease in cats and dogs. IRIS Establishes Napa Meeting to Advance Leading-Edge Directions in Nephrology.

Read the Press Release


Early detection of CKD

IDEXX SDMA™ is a revolutionary new kidney function test that will enable veterinarians to diagnose CKD in cats and dogs months or even years earlier than traditional methods, making it possible to intervene earlier and more effectively manage kidney disease.



The Urine Protein Creatinine Ratio is a fully quantitative measure of urinary protein loss. This simple urine test is beneficial for assessing glomerular damage and monitoring progression and/or regression of glomerular disease as well as response to treatment.


Synopses from the scientific literature

Symmetric Dimethylarginine Assay Validation, Stability, and Evaluation as a Marker for the Early Detection of Chronic Kidney Disease in Dogs
M.B. Nabity, G.E. Lees, M.M. Boggess, M. Yerramilli, E. Obare, M. Yerramilli, A. Rakitin, J. Aguiar, and R. Relford
The goal of this study was to validate the new IDEXX SDMA™ assay and compare SDMA with serum creatinine concentration (sCr) and GFR for early detection of decreasing kidney function in dogs with chronic kidney disease (CKD). IDEXX SDMA™ was determined to be useful for both early identification as well as monitoring of decreased renal function in dogs with CKD.
Comparison of Serum Concentrations of Symmetric Dimethylarginine and Creatinine as Kidney Function Biomarkers in Cats with Chronic Kidney Disease
J.A. Hall, M. Yerramilli, E. Obare, M. Yerramilli, and D.E. Jewell
Symmetric dimethylarginine (SDMA) has been shown to be an accurate and precise biomarker for calculating estimated glomerular filtration rate (GFR) in humans, as well as a more sensitive biomarker than serum creatinine concentration (sCr) for assessing renal dysfunction. Using serum SDMA as a biomarker for CKD allows earlier detection of CKD in cats compared with sCr, which may be desirable for initiating renoprotective interventions that slow progression of CKD.
Relationship between Serum Symmetric Dimethylarginine Concentration and Glomerular Filtration Rate in Cats
J. Braff, E. Obare, M. Yerramilli, J. Elliott, and M. Yerramilli
Direct measurement of glomerular filtration rate (GFR) is the preferred method to assess renal function in cats, but it is not widely used in the diagnosis of chronic kidney disease (CKD). In cats with CKD, symmetric dimethylarginine (SDMA) has been shown to increase and to correlate with GFR and plasma creatinine concentrations. Increased serum SDMA concentrations were observed in cats with reduced renal function as determined by direct measurement of GFR. This finding indicates that SDMA could have clinical applications in the diagnosis of CKD in cats.

How to get your IDEXX SDMA™ diagnostics?

Good news, if you are an IDEXX reference laboratory customer IDEXX SDMA™ is automatically included in many screens and profiles that contain CREA.

IDEXX SDMA™ may also be ordered as a stand-alone or follow-up test. Please log into IDEXX VetConnect™ PLUS and view the ORDER DIAGNOSTICS option or review the IDEXX SDMA™ options in your Directory of Products and Services.

Profiles and screens including IDEXX SDMA™ are:

1. IDEXX SMDA™ is included in the following screens and profiles:
  • General Health Screen
  • Cardiac
  • Kidney
  • Diabetes Monitoring
  • Vomiting dog / Pancreatitis
  • Old thin cat
  • Under the weather cat
2. Adding IDEXX SDMA™ to any other screen or profile: please use the code ‘ASDMA’
3. Stand-alone: please use the code ‘SDMA’
4. Follow-on after in-clinic testing: please use the code ‘FSDMA’

If you are not an IDEXX reference laboratory customer, please click here to experience the benefits of IDEXX SDMA™.