Urine protein
Urine ·Also called: PRO, protein urine, proteinuria, urine dipstick protein
What it is
Healthy kidneys hold protein back in the bloodstream, so urine should contain almost none. The dipstick pad gives a rough grade from trace to four plus, but it responds to how concentrated the urine is and gives frequent false positives in alkaline samples and in cats.
Why your vet measures it
Protein in urine can mean the kidney filter is damaged — an important and treatable finding — or simply that there is blood, pus or inflammation somewhere in the urinary tract. Separating those requires the sediment examination and, if the tract looks clean, a UPC ratio.
What a positive result can mean
- Damage to the kidney's filtering membrane, which needs quantifying with a UPC
- Inflammation or infection anywhere in the urinary tract
- Blood in the urine, from stones, cystitis or a tumour
- Very concentrated urine, which can push a healthy amount of protein above the detection threshold
- Alkaline urine, a known cause of false positives on the dipstick
- Fever, strenuous exercise, or a seizure shortly before collection
What a negative result means
- A negative result is the expected finding in a healthy dog or cat
Dogs and cats differ
The dipstick over-reads protein in feline urine often enough that a positive in a cat should always be confirmed rather than acted on. In both species, a positive is meaningless until the sediment has been checked for blood and infection.
Questions worth asking your vet
- What did the sediment show — was there blood or infection to explain this?
- Should we run a UPC ratio to quantify it?
- How concentrated was the sample?
Related terms
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