Clinical decision support
IRIS CKD staging calculator
Stage chronic kidney disease and substage by proteinuria and hypertension.
Reference ranges & assumptions
IRIS 2023 Staging Criteria
Dogs — Creatinine
Stage 1: <1.4
Stage 2: 1.4–2.8
Stage 3: 2.9–5.0
Stage 4: >5.0
Cats — Creatinine
Stage 1: <1.6
Stage 2: 1.6–2.8
Stage 3: 2.9–5.0
Stage 4: >5.0
SDMA (both species)
Stage 1: <18
Stage 2: 18–25
Stage 3: 26–38
Stage 4: >38
UPC Substaging
Dog: pN <0.2, pB 0.2–0.5, pA >0.5
Cat: pN <0.2, pB 0.2–0.4, pA >0.4
BP Substaging: No HT <140 | Risk 140–159 | HT 160–179 | Severe HT ≥180
Safety checks
- This tool supports calculation and education only.
- It does not diagnose, prescribe, or replace current clinical references.
- Verify patient-specific decisions with current IRIS guidelines and clinical judgment.
- Staging requires stable, hydrated patients. Dehydration and acute illness can falsely elevate creatinine.
- Always confirm hypertension with serial measurements.
Basis and limits
- Staging basis: IRIS 2023 CKD Guidelines. Stage by the worse of creatinine or SDMA.
- Creatinine thresholds: Dog Stage 1 <1.4, Stage 2 1.4–2.8, Stage 3 2.9–5.0, Stage 4 >5.0 mg/dL. Cat Stage 1 <1.6, Stage 2 1.6–2.8, Stage 3 2.9–5.0, Stage 4 >5.0 mg/dL.
- SDMA thresholds: Stage 1 <18, Stage 2 18–25, Stage 3 26–38, Stage 4 >38 µg/dL (both species).
- Substaging: Proteinuria by UPC: dogs (<0.2 pN, 0.2–0.5 pB, >0.5 pA); cats (<0.2 pN, 0.2–0.4 pB, >0.4 pA). BP by systolic (<140 no HT, 140–159 risk, 160–179 HT, ≥180 severe).
- Scope: decision support. Final staging requires clinical correlation and serial testing.