Dog with low blood sugar (hypoglycaemia)

Recognise the signs

• Wobbliness, weakness, stumbling
• Glassy, distant stare
• Trembling or shivering
• Disorientation, head pressing
• Seizures
• Collapse, unresponsiveness
• In puppies: cold to touch, not lifting head, refusing to eat

First aid steps

1. If the dog is conscious and able to swallow, smear a teaspoon of honey, golden syrup, or glucose gel onto the gums (not down the throat) — sugar absorbs through the gums.
2. If unconscious, still smear sugar onto the gums but DO NOT pour liquid into the mouth — risk of inhalation.
3. Wrap in a blanket to warm.
4. Phone the vet immediately and head to the practice — this is a stop-gap, not a fix.
5. If the dog seizes, see pet-seizure for further first aid.

While transporting to the vet

• Keep warm with a blanket.
• Reapply gum sugar every 5–10 minutes while travelling if the dog remains conscious.
• Phone ahead — IV glucose will be prepared.
• Bring any insulin, food packaging, or known toxin sources.

Common causes

• Toy-breed puppies (Yorkshire Terrier, Chihuahua, Pomeranian) missing a meal, especially when stressed or cold
• Diabetic dogs with too much insulin or a missed meal
• Working and hunting dogs with sustained intense exercise (hunting hypoglycaemia)
• Severe liver disease
• Insulinoma (insulin-secreting tumour, usually older dogs)
• Addisonian crisis
• Sepsis or severe infection
• Xylitol poisoning — sugar-free gum, sweets, peanut butter

What the vet will need to know

• Age, breed, and weight
• Diabetic status — last insulin dose, last meal, brand and type of insulin
• Recent activity (sustained exercise)
• Possible xylitol or other toxin access
• Time signs started and progression
• Any sugar already given at home

Aftercare

• Treatment includes IV glucose, fluids, and identifying the underlying cause.
• Diabetic dogs may need insulin dose review.
• Toy-breed puppies need frequent small meals (every 3–4 hours) and a temperature-controlled environment.
• Insulinoma requires further imaging and often surgery.
• Xylitol cases need 24–72 hours of monitoring for liver damage.

Prevention

• Toy-breed puppies: small frequent meals, never miss a meal, warm environment, sugar gel on hand.
• Diabetic dogs: strict feeding-and-insulin schedule, never skip a meal, vet review if appetite drops.
• Working and hunting dogs: pre-feed appropriately, carry glucose gel in the field.
• No xylitol products in the house — read labels on gum, sweets, peanut butter, baking, toothpaste.
• Annual bloods in older dogs catch insulinoma and Addisonian patterns early.

Breed-specific notes

• Toy breeds — Yorkshire Terrier, Chihuahua, Pomeranian, Maltese — are highest risk in puppyhood.
• Working breeds (Pointers, Setters, Spaniels) at risk during hunting season.

Frequently asked questions

Related topics

• Dog or cat having a seizure (fitting)
• Dog or cat that has collapsed
• Dog has eaten xylitol (sugar-free sweetener)
• Suspected poisoning in a dog or cat