Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: The two most common diabetic emergencies in dogs are low blood sugar (hypoglycemia), usually from too much insulin or not eating, and diabetic ketoacidosis (DKA), a dangerous complication of uncontrolled diabetes. Low blood sugar causes weakness, trembling, wobbliness, confusion, and seizures. DKA causes vomiting, not eating, weakness, fast breathing, and sometimes a sweet smell on the breath. Both need a vet right away.
Low blood sugar (hypoglycemia)
Signs
- Weakness, lethargy, or sleepiness
- Trembling or twitching
- Wobbly walking, or confusion
- Restlessness or unusual behavior
- Seizures or collapse
What to do
- If your dog is awake and can swallow, offer a meal. If it won’t eat, rub a small amount of corn syrup or honey on the gums.
- If your dog is seizing or unconscious, don’t put anything in its mouth, and don’t put your fingers near it. Go to an emergency vet.
- Call your vet in all cases, even if your dog recovers, and don’t give the next insulin dose until you’ve spoken to them.
Common causes
- Giving insulin when your dog didn’t eat, or ate less
- A double dose (two people each giving insulin)
- Using the wrong syringe for the insulin type (U-40 vs. U-100)
- Extra exercise
- A dose increase that’s too high
Diabetic ketoacidosis (DKA)
Signs
- Not eating
- Vomiting or diarrhea
- Weakness and lethargy
- Fast or deep breathing
- Sweet or nail-polish-remover smell on the breath
- Dehydration
- Collapse
DKA often occurs in newly diagnosed dogs or dogs with another illness, such as pancreatitis or an infection. It requires hospital treatment with IV fluids, insulin, and electrolyte management.
Other urgent signs in diabetic dogs
- Sudden blindness or red, painful eyes (cataracts and eye inflammation)
- Straining to urinate or blood in the urine (infection)
- Rapid weight loss despite insulin
Preventing emergencies
- Feed before giving insulin, and give insulin only if your dog ate normally, unless your vet tells you otherwise.
- Use a written log or app to record each dose, and assign one person to give insulin.
- Always match syringes to the insulin concentration.
- Never change doses without your vet.
- Keep corn syrup or honey at home, and know your nearest emergency clinic.
- Keep regular monitoring visits.
What to avoid
- Giving insulin to a dog that isn’t eating or is vomiting without calling your vet.
- Giving a second dose if you’re unsure whether the first was given.
- Waiting if your diabetic dog stops eating or vomits repeatedly.
More on long-term care: diabetes in senior dogs.
Frequently asked questions
What happens if I miss an insulin dose?
A single missed dose is rarely an emergency. Give the next dose at the usual time, and call your vet if you’re unsure.
How fast does low blood sugar happen?
It can develop within hours of an insulin dose.
Can DKA be treated?
Yes. Many dogs recover with intensive hospital care, especially when treated early.
Sources
- Behrend E, et al. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2018
- Merck Veterinary Manual: Diabetes mellitus in dogs and cats
- Merck Veterinary Manual: Diabetic ketoacidosis
- Hume DZ, et al. Outcome of dogs with diabetic ketoacidosis: 127 dogs (1993–2003). J Vet Intern Med. 2006
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.