Fructosamine Test for Dogs and Cats: What It Shows Your Vet

Quick answer

Fructosamine reflects average glucose over roughly the previous week to ten days. It can be useful when a single reading is unreliable, especially in cats whose glucose may rise with stress. Your vet interprets it alongside symptoms, history and other tests.

Why it helps

A spot reading is one moment. Fructosamine offers a broader window, which can help your vet understand whether a high reading is persistent or may reflect a short-lived change.

Cats and stress hyperglycaemia

Cats can have a marked glucose response to handling and clinic visits. Fructosamine is one way a vet may look beyond that single stressful moment.

How it differs from a curve

A glucose curve shows readings across a shorter dosing interval and helps your vet see timing and patterns. Fructosamine covers a longer period. Neither result should be used by an owner to change treatment alone.

What the result means

The number is interpreted in context with clinical signs, other tests, treatment and the individual pet. Ask your vet to explain what it means for your pet and what they want you to monitor.

Read the glucose curve guide, stress hyperglycaemia in cats and FAQ.

Sources

The pages below were each opened and checked before being listed here, and anything that could not be opened was left off rather than guessed at.

• 2025 iCatCare consensus guidelines on the diagnosis and management of diabetes mellitus in cats — Journal of Feline Medicine and Surgery 27:1–37, 2025. The window this page is built on, almost word for word: fructosamine indicates average glucose over the preceding seven to ten days or so. Also that it can read normal in early diabetes.
• ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats — Journal of Feline Medicine and Surgery 17(3):235–250, 2015. The same window from the earlier consensus — approximately the preceding week.
• Other Methods for Monitoring Glycemic Status (Section 14) — 2026 AAHA Diabetes Management Guidelines for Cats, 2026. Why one result is not a verdict: a well-managed diabetic can show a raised value and an uncontrolled one a normal value, and readings over time are more useful than a single number.
• Diabetes Mellitus in Dogs and Cats — MSD Veterinary Manual, reviewed May 2024, updated May 2026. The reason the test exists for cats: fructosamine is normal where the high glucose was caused by stress.
• General Monitoring Considerations — 2026 AAHA Diabetes Management Guidelines for Dogs, 2026. That no single monitoring tool reliably separates good control from poor, that results from different methods may conflict, and that they must be read against the clinical signs.