Cat Kidney Values Explained (BUN, Creatinine, SDMA)
If your cat's bloodwork shows elevated kidney values like BUN, Creatinine, or SDMA, it can be confusing and concerning. This guide explains what these numbers mean, why they matter, and how to understand them in context.
What Are Cat Kidney Values?
- BUN (Blood Urea Nitrogen): A waste product filtered by the kidneys. When kidneys aren't functioning optimally, BUN levels rise.
- Creatinine: Another waste product that's closely linked to kidney function. It's often considered more reliable than BUN for assessing kidney health.
- SDMA (Symmetric Dimethylarginine): An early marker that can detect kidney disease before creatinine levels rise, making it valuable for early intervention.
Normal Ranges (may vary by lab):
- • BUN: 10–30 mg/dL
- • Creatinine: 0.8–2.4 mg/dL
- • SDMA: 0–14 µg/dL
Why Kidney Values Matter in Cats
Cats are particularly prone to chronic kidney disease (CKD), especially as they age. Studies show that up to 30% of cats over 10 years old develop some degree of kidney disease. Tracking these values helps veterinarians catch kidney problems early and guide treatment decisions that can significantly improve quality of life.
Common Causes of Elevated Kidney Values
- High BUN: Dehydration, high-protein diet, gastrointestinal bleeding, or kidney disease
- High Creatinine: More directly linked to kidney dysfunction and less affected by external factors
- High SDMA: Sensitive early warning sign of CKD, often elevated before other markers
Want to know if your cat's values indicate early CKD or just dehydration?
Upload bloodwork to VetLens and get an instant, plain-English explanation tailored to your cat's specific situation.
Try VetLens FreeSymptoms Pet Owners Might Notice
- • Drinking more water than usual
- • Urinating more frequently or in larger amounts
- • Weight loss despite normal or increased appetite
- • Reduced appetite or becoming pickier about food
- • Vomiting or lethargy
- • Bad breath with a chemical odor
What Happens Next?
Your veterinarian may recommend:
- • Repeat bloodwork to confirm trends and rule out temporary elevations
- • Urine testing to assess kidney concentration ability
- • Imaging (ultrasound) to evaluate kidney structure
- • Prescription kidney diets that are lower in protein and phosphorus
- • Supportive medications including fluids, phosphorus binders, and appetite stimulants
- • Blood pressure monitoring as hypertension often accompanies kidney disease
Key Takeaway:
Kidney values show how well your cat's kidneys are functioning. Mild changes may only need monitoring, while severe or persistent changes guide treatment decisions. Early detection and management can significantly slow disease progression.
Want Kidney Values Explained for Your Cat?
Upload your cat's bloodwork into VetLens and get:
- ✓ Plain-English explanations of BUN, Creatinine, and SDMA
- ✓ Context on whether changes are due to dehydration, diet, or CKD
- ✓ Suggested questions to ask your vet
- ✓ Tailored diet and supplement recommendations
Frequently Asked Questions
What is SDMA and why is it important?
SDMA is an early marker of kidney function that often rises before creatinine. It can detect kidney disease when only 25% of kidney function is lost, compared to creatinine which typically rises after 75% loss.
What causes high BUN in cats?
High BUN can result from kidney disease, dehydration, high-protein diet, or gastrointestinal bleeding. Your vet will consider other values and clinical signs to determine the cause.
What is a dangerous creatinine level?
Values above 2.4 mg/dL are considered abnormal. Levels above 4.0 mg/dL often indicate advanced kidney disease requiring intensive management.
Can kidney disease be treated?
While there's no cure for chronic kidney disease, proper diet, medications, and supportive care can slow progression and significantly improve quality of life. Many cats live years with well-managed kidney disease.