Blood Urea Nitrogen (Feline)

Also known as:BUNUrea

Reference Range

Critical Low

mg/dL

Reference Range

16-36

mg/dL

Critical High

>100

mg/dL

Also reported in: mmol/L

BUN is a waste product filtered by the kidneys. Normal levels mean the kidneys are filtering blood properly.

Low

Low BUN is often seen with low-protein diets or liver issues.

What to do:

Discuss your cat's diet and liver health with your vet.

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Feline BUN: 10 mg/dL (Low)

Normal

BUN is a waste product filtered by the kidneys. Normal levels mean the kidneys are filtering blood properly.

What to do:

No action needed.

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Feline BUN: 25 mg/dL

High

High BUN in cats is a very common early sign of Chronic Kidney Disease (CKD), though it can also just mean dehydration.

What to do:

Your vet will likely check An early kidney marker (SDMA), creatinine, and urine concentration to confirm kidney function.

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Feline BUN: 45 mg/dL (High)

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