Lab value · UPC
Urine Protein:Creatinine Ratio in cats, explained
UPC measures how much protein is leaking into the urine. Healthy kidneys keep protein in the blood.
What a higher urine protein:creatinine ratio can mean
A higher UPC means more protein is leaking. IRIS considers a UPC above 0.4 “proteinuric” in cats — something vets often monitor and may treat.
What a lower urine protein:creatinine ratio can mean
A lower UPC means less protein leaking — a good sign, and sometimes a sign treatment is working.
Why it matters in kidney disease
- IRIS uses UPC to “substage” CKD as non-proteinuric, borderline or proteinuric.
- Persistent protein in the urine is linked with faster progression, so vets often treat it and recheck.
- A urinary tract infection or blood in the sample can raise UPC, so vets usually check the urine sediment too.
IRIS reference substages
IRIS uses the urine protein:creatinine ratio to describe protein loss in the urine of cats with CKD.
| UPC | IRIS substage |
|---|---|
| < 0.2 | Non-proteinuric |
| 0.2 – 0.4 | Borderline proteinuric |
| > 0.4 | Proteinuric |
Source: IRIS Staging of CKD (modified 2023) — iris-kidney.com; phosphate targets: 2026 iCatCare consensus guidelines.
Questions to ask your vet
Ask your vet
- Is my cat’s UPC high enough to treat?
- Should we recheck UPC after starting treatment?
Decode your cat’s UPC
Enter your cat’s values and get a plain-English summary, IRIS reference bars and questions for your vet.
Frequently asked questions
What is Urine Protein:Creatinine Ratio in a cat blood test?
UPC measures how much protein is leaking into the urine. Healthy kidneys keep protein in the blood.
What does a high urine protein:creatinine ratio mean in cats?
A higher UPC means more protein is leaking. IRIS considers a UPC above 0.4 “proteinuric” in cats — something vets often monitor and may treat.
What does a low urine protein:creatinine ratio mean in cats?
A lower UPC means less protein leaking — a good sign, and sometimes a sign treatment is working.
What is a normal urine protein:creatinine ratio level for a cat?
A typical feline reference interval is about Example only: 0.00 – 0.20. Use the range printed on your cat’s report — it differs between labs., but every lab sets its own range. The range printed on your cat’s report is the one to use.
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