Puppy low blood sugar (hypoglycaemia)
A small or young puppy that becomes wobbly, weak, glassy-eyed, cold or starts twitching or seizing may have low blood sugar (hypoglycaemia), which can develop within hours of missing a meal, getting cold, or being stressed. If your puppy is still able to swallow, you can rub a little honey or glucose syrup onto the gums and keep them warm while you call a veterinarian immediately. Do not give anything by mouth to a seizing or unconscious puppy. Toy breeds and very young puppies are at highest risk.
Go to a vet now if
- Sudden weakness, wobbliness, or a glassy, dazed look
- Trembling, twitching, collapse or seizures
- Cold body, or unresponsiveness
- A toy-breed or very young puppy who has missed meals or is unwell
Call a vet today if
- A brief dip in energy that fully resolves after a normal meal (mention it to your vet)
What to tell the vet
- Your puppy's age, breed and weight
- When they last ate
- The signs and how fast they came on
- Whether you've given honey/glucose and the response
- Any vomiting, diarrhoea or other illness
- Whether they are warm or cold
What not to do
- Do not put anything in the mouth of a seizing or unconscious puppy — it can be inhaled
- Do not let the puppy get cold — warmth is important
- Do not assume recovery after honey means no vet visit is needed
What your vet may check
Your vet will check blood sugar, warm and stabilise your puppy, and look for an underlying cause such as infection, parasites or a portosystemic shunt. Ongoing feeding advice helps prevent recurrence.
Recovery support after veterinary assessment
Once stable, frequent small meals and keeping warm help prevent further dips. Your vet may recommend palatable, energy-dense support such as Alfavet ReConvales Energy or Power to help maintain intake during recovery, used on veterinary advice.
Frequently asked questions
What causes low blood sugar in puppies?
Missing meals, cold, stress, heavy parasite burden, infection or being a very small toy breed can all trigger hypoglycaemia. Young puppies have little reserve, so it can develop quickly.
What do I do if my puppy collapses from low blood sugar?
If conscious and able to swallow, rub a little honey or glucose syrup on the gums and keep them warm, then call a vet immediately. Give nothing by mouth if seizing or unconscious.
How can I prevent puppy hypoglycaemia?
Feed small, frequent meals, keep your puppy warm, reduce stress, and follow your vet's parasite and feeding plan. Discuss any recurring episodes with your vet.
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Sources & standards
Emergency guidance follows AVMA, Merck Veterinary Manual, ASPCA Animal Poison Control, and small-animal emergency-medicine standards, reviewed by our veterinary advisory board.