Urine Dipstick: Cat Kidney Disease Glossary

A urine dipstick is a rapid diagnostic tool used during a standard urinalysis to provide a chemical snapshot of a cat's health. While it is a "semi-quantitative" test (meaning it provides a range rather than an exact number), it is a vital screening tool for identifying complications that often go hand-in-hand with Chronic Kidney Disease.

How it Works A plastic strip with several reagent pads is dipped into a fresh urine sample. Each pad changes color based on the concentration of a specific substance. The vet or technician then compares these colors to a reference chart on the side of the bottle.

Key Markers for the CKD Cat

Protein: As we discussed, this is the most critical pad for a CKD cat. It detects Albumin. In a cat with dilute urine, even a "trace" or "1+" result is significant and usually triggers a more precise UPC (Urine Protein:Creatinine Ratio) test.
Glucose (Sugar): Normally, there should be no glucose in a cat's urine.
- If glucose is present along with high blood sugar, the cat may have Diabetes Mellitus.
- If glucose is present but blood sugar is normal, it indicates Renal Glucosuria. This means the kidney tubules are so damaged they can no longer "reclaim" sugar, which is a sign of advanced tubular injury.
Blood / Hemoglobin: This pad detects red blood cells or free hemoglobin. In CKD cats, this can indicate kidney stones, a urinary tract infection (UTI), or "uremic gastritis" if the cat is also bleeding elsewhere.
pH: This provides the acidity/alkalinity measurement. As noted before, very acidic urine suggests a risk for calcium oxalate stones, while very alkaline urine often signals a bacterial infection.
Bilirubin: While a tiny amount can be normal in dogs, any bilirubin in a cat's urine is considered abnormal and usually points toward liver disease or the breakdown of red blood cells.
Ketones: The presence of ketones indicates the body is burning fat for energy instead of glucose. This is a red flag for Diabetic Ketoacidosis (DKA) or extreme starvation/muscle wasting.

The Limitations of the Dipstick in CKD

Specific Gravity: Most dipsticks have a pad for Specific Gravity (USG), but it is notoriously inaccurate in cats. Vets will almost always ignore this pad and use a manual device called a refractometer instead.
Leukocytes (White Blood Cells): The leukocyte pad on a human or standard veterinary dipstick is highly unreliable for cats, often giving "false positives." If a vet suspects an infection, they will look for white blood cells manually under a microscope rather than trusting the dipstick.
Nitrites: While useful in humans to detect UTIs, this pad is generally useless in feline medicine because the types of bacteria that infect cats do not always produce nitrites.

The "Color Interference" Factor If a cat's urine is very dark (from dehydration) or contains a lot of blood, the pigments can stain the pads, making it difficult to read the chemical color change accurately. This is why a dipstick is always interpreted alongside a "sediment exam," where the vet looks at the urine under a microscope.

Disclaimer: This content is for educational purposes only and does not constitute veterinary medical advice. Always consult with your primary care veterinarian or a veterinary internal medicine specialist regarding your cat’s specific condition.

Key Markers for the CKD Cat

Protein: As we discussed, this is the most critical pad for a CKD cat. It detects Albumin. In a cat with dilute urine, even a "trace" or "1+" result is significant and usually triggers a more precise UPC (Urine Protein:Creatinine Ratio) test.
Glucose (Sugar): Normally, there should be no glucose in a cat's urine.
- If glucose is present along with high blood sugar, the cat may have Diabetes Mellitus.
- If glucose is present but blood sugar is normal, it indicates Renal Glucosuria. This means the kidney tubules are so damaged they can no longer "reclaim" sugar, which is a sign of advanced tubular injury.
Blood / Hemoglobin: This pad detects red blood cells or free hemoglobin. In CKD cats, this can indicate kidney stones, a urinary tract infection (UTI), or "uremic gastritis" if the cat is also bleeding elsewhere.
pH: This provides the acidity/alkalinity measurement. As noted before, very acidic urine suggests a risk for calcium oxalate stones, while very alkaline urine often signals a bacterial infection.
Bilirubin: While a tiny amount can be normal in dogs, any bilirubin in a cat's urine is considered abnormal and usually points toward liver disease or the breakdown of red blood cells.
Ketones: The presence of ketones indicates the body is burning fat for energy instead of glucose. This is a red flag for Diabetic Ketoacidosis (DKA) or extreme starvation/muscle wasting.

The Limitations of the Dipstick in CKD

Specific Gravity: Most dipsticks have a pad for Specific Gravity (USG), but it is notoriously inaccurate in cats. Vets will almost always ignore this pad and use a manual device called a refractometer instead.
Leukocytes (White Blood Cells): The leukocyte pad on a human or standard veterinary dipstick is highly unreliable for cats, often giving "false positives." If a vet suspects an infection, they will look for white blood cells manually under a microscope rather than trusting the dipstick.
Nitrites: While useful in humans to detect UTIs, this pad is generally useless in feline medicine because the types of bacteria that infect cats do not always produce nitrites.