FrançaisProtein on the dipstick: read it with the urine concentration
Normal urine contains little protein. A negative to trace result is usual in concentrated urine (specific gravity above 1.025), and some healthy dogs with very concentrated urine reach 2+. In dilute urine (below 1.015), even trace to 1+ means excess protein. A result above 2+ is significant whatever the concentration [1].
The dipstick is mostly sensitive to albumin and is only semi-quantitative. Very alkaline urine (pH 8 or more) can give a false positive [1]. A positive strip is therefore usually followed by a UPC.
How to read the UPC line
Here is an example line from a dog’s urine chemistry.
- Abbreviation UPC, UP:UC or UPCR. In French, RPCU.
- Result 1.8 in this illustrative line: more protein than a healthy kidney lets through.
- Unit A ratio has no unit: urine protein divided by urine creatinine, which corrects for how concentrated the urine is [1].
- Laboratory interval Below 0.2 is non-proteinuric in both species according to IRIS [2].
- Flag H: above the interval. The next step is to check the urine sediment for infection or blood, then repeat the test [1, 2].
UPC cut-offs: the IRIS substages
| UPC | Dogs | Cats |
|---|---|---|
| Non-proteinuric | below 0.2 | below 0.2 |
| Borderline proteinuric | 0.2–0.5 | 0.2–0.4 |
| Proteinuric | above 0.5 | above 0.4 |
Cornell adds that a UPC of 2 or more in a dog fits protein leaking through the kidney filters (glomerular disease); milder increases more often come from the tubules [1]. Some healthy male cats can reach 0.6 [1].
Where the protein comes from
- Outside the kidneys (“post-renal”). Infection or inflammation of the bladder, prostate or genital tract, and blood in the urine, add plasma proteins. The UPC is unreliable when the sediment shows inflammation; in dogs with E. coli infections it can be as high as 40 [1].
- Overload (“pre-renal”). Small proteins in excess in the blood, such as hemoglobin from red cell destruction, spill into the urine [1].
- Functional. Fever, exercise, stress or heart failure can cause a mild, often transient proteinuria [1].
- Kidney disease. Glomerular disease (glomerulonephritis, amyloidosis) causes the largest losses; tubular damage causes milder ones [1].
The 2004 ACVIM consensus recommends localising the proteinuria, checking that it persists and measuring its size before deciding what to do [3].
Why persistent proteinuria matters
Persistent proteinuria of kidney origin usually indicates chronic kidney disease, and its detection identifies dogs and cats at higher risk of adverse outcomes [3]. It can appear before the kidneys lose their ability to concentrate urine or before creatinine rises [1]. IRIS uses the UPC, together with blood pressure, to substage chronic kidney disease [2]; high blood pressure can itself damage the kidneys [4].
Results often read with the UPC
For cats, see also creatinine and BUN in cats.
En français : protéinurie du chien et du chat.
Questions to ask your veterinarian
- Was the urine sediment clear of infection, inflammation and blood?
- How was the urine collected, and should the UPC be repeated?
- Which IRIS substage does this UPC correspond to?
- Should we check blood pressure and the kidney values?
- When should we recheck the UPC?
Get your pet’s urine and blood results explained together.
AI DiagAnimals reads the UPC with the urine specific gravity, the sediment and the kidney values, using your laboratory’s intervals, and prepares the questions for your vet. The service opens soon: leave your email to be told first.
Frequently asked questions
Why is there protein in my dog’s urine?
It can come from the urinary tract (infection, inflammation, blood), from excess small proteins in the blood, from fever or exercise, or from kidney disease. A UPC on a clean sample tells them apart [1, 3].
Does protein in urine always mean kidney failure?
No. Many causes are outside the kidneys and some are transient. Persistent proteinuria from the kidneys, confirmed on repeat samples, is the finding that points to kidney disease [1, 3].
What is a normal UPC for a dog or a cat?
Below 0.2 in both species. IRIS calls a dog proteinuric above 0.5 and a cat above 0.4 [2].
Can protein in a dog’s urine be reversed?
It depends on the cause: proteinuria from an infection resolves with treatment. Kidney proteinuria can often be reduced with treatment chosen by your vet, and the UPC is used to follow it [3].
What is the life expectancy of a dog with protein in its urine?
There is no single answer: it depends on the cause, the size of the loss and the kidney function. Persistent kidney proteinuria is associated with a higher risk, which is why it is monitored [3].
Sources
- eClinPath, Cornell University College of Veterinary Medicine. Chemical constituents: protein, protein to creatinine ratio. eclinpath.com/urinalysis/chemical-constituents
- International Renal Interest Society (IRIS). IRIS Staging of CKD, modified 2026. iris-kidney.com/s/IRIS_staging_guidelines-2026.pdf
- Lees GE et al. Assessment and management of proteinuria in dogs and cats: 2004 ACVIM Forum Consensus Statement (small animal). J Vet Intern Med. 2005;19(3):377-385. pubmed.ncbi.nlm.nih.gov/15954557
- Acierno MJ et al. ACVIM consensus statement: guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. J Vet Intern Med. 2018;32(6):1803-1822. doi.org/10.1111/jvim.15331
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.