Diabetic pet emergencies: when to call the vet urgently

This page is a scannable reference, not a substitute for veterinary care. Save your regular vet's number and your nearest out-of-hours number in your phone now, before they are needed.

Low blood sugar

Signs can include sudden weakness, wobbliness, trembling, disorientation, unusual sleepiness, collapse or seizures, often after insulin. If your pet is conscious, vets generally advise rubbing honey or glucose syrup on the gums and contacting your vet immediately. If unconscious or seizing, do not put anything in the mouth — go straight to the vet.

Read the full hypoglycaemia guide.

Diabetic ketoacidosis

Vomiting, refusing food, marked lethargy or weakness, dehydration and unusual breathing can indicate DKA. A sweet, acetone-like smell on the breath is sometimes described as well — but it is not a sign to wait for, because a good proportion of people cannot smell acetone at all, and its absence tells you nothing. It is a medical emergency and cannot be managed safely at home.

Contact your vet or an emergency clinic immediately.

Collapse or seizure

Collapse or a seizure is always urgent. Keep your pet safe from falls, do not put anything in their mouth, and contact an emergency vet immediately. If low blood sugar is suspected and your pet is conscious, follow the hypoglycaemia guidance while you make the call.

Repeated vomiting

Repeated vomiting can accompany DKA, severe illness or another emergency. Do not wait for it to pass or try to manage it from an article. Call your vet or emergency clinic immediately.

See what to do when your diabetic pet will not eat for the related safety guidance.

Refusing food

A diabetic pet that refuses food needs careful handling because insulin without food can be dangerous. Contact your vet before giving insulin, especially if refusal continues or your pet seems unwell. Read Diabetic dog or cat won't eat.

A missed or uncertain dose

Note what happened and the time, and contact your vet about the next dose rather than deciding yourself. Vets advise against giving a second dose to compensate for an injection that was missed or may not have gone in, because too much insulin is more dangerous than too little — but what to do about the next one is their call for your pet. Read the full missed or uncertain insulin dose guide.

Keep your emergency numbers ready

Save your vet, the nearest emergency practice and any relevant pet insurance or transport details in your phone today. Tell another person in your household where the emergency supplies are kept and what symptoms mean you should call.

For newly diagnosed owners, the Just Diagnosed guide helps you build a routine before an emergency happens.

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.

• Diabetic ketoacidosis in cats and dogs — Veterinary Ireland Journal, Poppy Gant BVSc MRCVS (RVC), 2019. The DKA picture described here: lethargy, anorexia, vomiting, dehydration and eventual collapse, with altered breathing as a response to metabolic acidosis.
• 2018 AAHA Diabetes Management Guidelines for Dogs and Cats — Journal of the American Animal Hospital Association 54(1):1–21, 2018. Hypoglycaemia first aid — a meal if the animal can eat, sugar on the gums if it cannot — and that an owner may skip a dose on suspicion of a hypo, but never add one.
• ISFM Consensus Guidelines on the Practical Management of Diabetes Mellitus in Cats — Journal of Feline Medicine and Surgery 17(3):235–250, 2015. The honey-or-glucose-on-the-gums measure as the recognised home bridge while transport is arranged.
• Caninsulin 40 IU/ml: package leaflet (Vm 06376/4083) — Veterinary Medicines Directorate, Defra, revised February 2026. That insulin overdose produces hypoglycaemia, the advice to keep glucose at home, and the rebound high that can follow a low.
• Dear Veterinarian Letter: safety conditions associated with the use of Senvelgo — FDA Center for Veterinary Medicine, 2024. That refusing food, lethargy, vomiting or weakness warrant immediate veterinary contact, and that DKA must be assessed regardless of the glucose reading.