Diabetic ketoacidosis: urine dipstick and beta-hydroxybutyrate
9-year-old female Miniature Schnauzer with one month of polyuria/polydipsia and vomiting and anorexia for 2 days. She is dehydrated and lethargic.
| Parameter | Result | Reference |
|---|---|---|
| Glucose | 520 mg/dL | 70–140 |
| Venous pH | 7.08 | 7.35–7.45 |
| Bicarbonate | 9 mEq/L | 18–24 |
| Anion gap | 32 mEq/L | 12–24 |
| Urine ketones (dipstick) | Trace | Negative |
Which statement is correct?
chevron_right Show answer and explanation
A. Trace ketonuria rules out ketoacidosis; the acidosis must be lactic
The dipstick can greatly underestimate ketosis. Lactic acidosis is possible in a dehydrated dog, but you cannot rule out ketoacidosis with this result.
B. It is hyperglycaemic hyperosmolar syndrome, without ketosis
Hyperosmolar syndrome presents with much higher glucose (often > 600 mg/dL), marked hyperosmolality and mild or no acidosis. A pH of 7.08 does not fit.
C. Repeat the urine dipstick in a few hours, as it is more sensitive than blood
Repeating the dipstick does not solve its limitation. Ketonaemia (blood beta-hydroxybutyrate) is more reliable than ketonuria and does not depend on obtaining urine.
D. The dipstick detects acetoacetate but not beta-hydroxybutyrate: measure blood beta-hydroxybutyrate
Correct. The nitroprusside reaction detects acetoacetate (and some acetone) but not beta-hydroxybutyrate, the predominant ketone in ketoacidosis. Measure blood beta-hydroxybutyrate with a handheld meter or at the laboratory.
lightbulb Key takeaway
Diagnose ketoacidosis with glucose, blood gas analysis and blood beta-hydroxybutyrate. During treatment, beta-hydroxybutyrate is converted to acetoacetate and the dipstick may 'worsen' while the patient improves: do not be alarmed.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.