Ketones in Diabetic Dogs and Cats: Why They Matter

Important: If your pet is vomiting, refusing food, very lethargic, or seems unwell, contact your vet immediately — even if their glucose reading looks fine.

Quick answer

Ketones build up when the body cannot use glucose normally and starts breaking down fat. A dangerous build-up can lead to diabetic ketoacidosis (DKA), an emergency. Cats taking the oral SGLT2 medicine Senvelgo can develop ketoacidosis while their glucose reading looks normal, so a reassuring number does not rule out a problem.

What ketones are

Ketones are produced when the body turns to fat for energy. Small amounts may prompt monitoring, but rising ketones alongside illness, food refusal or dehydration need urgent veterinary advice.

What ketoacidosis means

DKA is a serious metabolic emergency rather than simply a high glucose reading. Vomiting, dehydration, unusual breathing, marked lethargy and refusal to eat are warning signs. Do not wait for a routine appointment.

How testing works

Ketones may be checked with urine strips or a blood ketone meter at home, or with veterinary testing. Ask your vet which method is appropriate.

What happens about insulin is a decision for the vet seeing your pet, case by case. The thing to act on at home is the phone call.

When to contact your vet

Contact your vet immediately if your pet is vomiting, refusing food, very lethargic, dehydrated or simply seems unwell. This is particularly important for cats taking SGLT2 medicines. For low blood sugar guidance, read the hypoglycaemia guide; for a wider emergency reference, use diabetic pet emergencies.

Mello helps you keep a clear record to share with your vet. It does not diagnose ketoacidosis or interpret ketone results.

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.

• 2018 AAHA Diabetes Management Guidelines for Dogs and Cats — Journal of the American Animal Hospital Association 54(1):1–21, 2018. The instruction this page is built on: test urine periodically, record glucose and ketones, and contact your vet if ketones are present.
• Diabetic ketoacidosis in cats and dogs — Veterinary Ireland Journal, Poppy Gant BVSc MRCVS (RVC), 2019. Why a home urine strip tells you presence rather than severity: the strips detect acetoacetate, while beta-hydroxybutyrate is the prominent ketone in DKA.
• Senvelgo (velagliflozin): known risk of diabetic ketoacidosis in cats — Direct Healthcare Professional Communication — Boehringer Ingelheim, in agreement with the European Medicines Agency, 2024. That ketoacidosis on velagliflozin can occur at normal blood glucose, and the ketone-checking schedule for the first days of treatment.
• Dear Veterinarian Letter: safety conditions associated with the use of Senvelgo — FDA Center for Veterinary Medicine, 2024. That euglycaemic DKA is easily missed because glucose is not raised, and the owner-facing red flags: not eating, lethargy, vomiting, weakness.
• ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats — Journal of Feline Medicine and Surgery 17(3):235–250, 2015. That a positive urine ketone result indicates poor glycaemic control and warrants veterinary assessment.