When reviewing a cat's bloodwork, it is reasonable to ask whether SDMA would add useful information. The useful question is what testing fits this cat, rather than whether one marker can give a complete answer.
What does SDMA measure?
SDMA stands for symmetric dimethylarginine. It is a substance produced during normal protein turnover and cleared mainly by the kidneys. Its blood concentration helps assess the kidneys' filtration function. IRIS explains its role alongside creatinine.
SDMA can increase before creatinine exceeds the laboratory reference interval in some cats. A 2014 retrospective study found this in 17 of 21 cats with chronic kidney disease. That small study supports its usefulness, but does not guarantee earlier detection in every cat or prove that screening alone prolongs life.
How does it compare with other tests?
| Test | Useful information | Important limitation |
|---|---|---|
| SDMA | Helps assess kidney filtration; may identify changes earlier than creatinine | Requires clinical context and follow-up |
| Creatinine | An established kidney-function marker; trends can be informative | Muscle mass can affect the result |
| BUN | Another blood measurement considered in a kidney evaluation | Diet, hydration, and other factors can influence it |
Creatinine remains useful. A result within its reference interval does not always exclude kidney disease, especially in a cat with little muscle mass. Cornell describes why blood and urine results must be interpreted together.
Does a high SDMA mean chronic kidney disease?
One elevated result is not a diagnosis of chronic kidney disease (CKD). IRIS treatment guidance makes this distinction explicit.
A vet may repeat bloodwork and assess urine concentration, urine protein, blood pressure, hydration, and other findings. CKD staging follows diagnosis and applies to a stable patient. IRIS explains diagnosis and staging.
Hydration and normal biological variation can affect SDMA. Use the reference interval printed by the testing laboratory, and ask how the result compares with previous measurements. IDEXX's FAQs discuss these limitations; IDEXX is a test provider, so this article also uses independent veterinary guidance.
How often should a cat be tested?
There is no single SDMA schedule for every cat. For apparently healthy cats, the 2021 AAHA/AAFP life-stage guidance places SDMA within a broader diagnostic plan:
- Ages 1–6: consider testing according to the individual cat; establish a baseline, then test as needed.
- Ages 7–10 (mature adult): diagnostic screening every 1–2 years is recommended.
- Over 10 (senior): screening at least yearly, with every six months recommended.
These are consensus recommendations, not a prescription for each animal. Symptoms, existing disease, and previous abnormalities may require earlier testing. Ask your vet which tests and interval fit your cat.
What should happen after testing?
If CKD is confirmed, care is tailored to the stage and complications. A vet may discuss nutrition, hydration, and monitoring. A kidney diet is not an automatic response to one high SDMA result. IRIS treatment recommendations describe an individualized approach. Testing itself is not treatment, and no test promises a particular lifespan.
Useful questions for the appointment:
- Would SDMA add information to this blood panel?
- Should we also arrange laboratory urinalysis or blood-pressure measurement?
- Do these results need a recheck, and when?
Home urine strips do not replace SDMA blood testing or a veterinary kidney assessment. If your vet requests urine, see our sample-collection guide and follow the clinic's instructions.
When should you seek help sooner?
Increased thirst, changes in urination, weight loss, poor appetite, or vomiting warrant veterinary assessment; these signs have several possible causes. Cornell describes signs associated with CKD.
Repeated straining with little or no urine requires immediate emergency veterinary care. Do not wait for a routine blood test. Cornell explains why suspected urinary obstruction is an emergency.
For a Thai overview of symptoms, see สัญญาณโรคไตในแมวที่ควรสังเกต.
Sources used
- IRIS: Overview of the CKD staging system
- IRIS: Treatment recommendations for cats with CKD (2023)
- AAHA/AAFP: Diagnostic testing for each feline life stage (2021)
- Cornell Feline Health Center: Chronic kidney disease
- Hall et al. (2014): SDMA and creatinine as kidney-function biomarkers in cats
- IDEXX: SDMA testing resources and FAQs
- Cornell Feline Health Center: Lower urinary tract disease
Sources checked: 2026-10-02
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