Lab values explained
Your cat’s lab report, one value at a time.
What each number measures, what higher or lower can mean, the IRIS reference ranges where they exist, and good questions to bring to your vet.
The kidney values
These are the values vets look at most closely for cats with chronic kidney disease.
Creatinine
Creatinine is a waste product made by muscles. Healthy kidneys filter it out of the blood, so when kidney filtering drops, creatinine rises.
Read more →SDMASDMA
SDMA is a newer kidney marker. Like creatinine, it is cleared by the kidneys, but it is less affected by muscle mass — useful for older, thinner cats.
Read more →BUNBlood Urea Nitrogen
BUN measures urea, a waste product from breaking down protein. The kidneys remove it, so it often rises with kidney disease.
Read more →PHOSPhosphorus
Phosphorus is a mineral from food. When kidneys filter less, it builds up in the blood — and high phosphorus is linked to faster CKD progression.
Read more →KPotassium
Potassium is an electrolyte essential for muscles and nerves. Cats with CKD often lose potassium in their urine.
Read more →USGUrine Specific Gravity
USG shows how concentrated the urine is. Healthy cat kidneys make very concentrated urine; kidneys with CKD lose that ability.
Read more →UPCUrine Protein:Creatinine Ratio
UPC measures how much protein is leaking into the urine. Healthy kidneys keep protein in the blood.
Read more →HCTHematocrit (PCV)
Hematocrit is the share of the blood made up of red blood cells. Kidneys make a hormone (EPO) that tells the body to make red cells.
Read more →Have a report in front of you?
Type the numbers into the free Lab Decoder for a plain-English summary in seconds.
Other values on a blood panel
- Calcium (Ca)
- Sodium (Na)
- Chloride (Cl)
- Hemoglobin (HGB)
- Red Blood Cells (RBC)
- White Blood Cells (WBC)
- Albumin (ALB)
- Total Protein (TP)
- Glucose (GLU)
- ALT (ALT)
- Alkaline Phosphatase (ALKP)
- Total T4 (thyroid) (T4)
- Cholesterol (CHOL)
- Total Bilirubin (TBIL)
KidneyPaw explains lab values for information only. It does not diagnose, stage or treat. Always discuss results and any changes in care with your veterinarian.
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