Suspect poisoning? US: ASPCA Poison Control (888) 426-4435 · UK: 01202 509 000 · Severe symptoms → nearest emergency vet now.

Diabetes Medicines (Metformin, Insulin)

Insulin and oral diabetes drugs can push a pet’s blood sugar far too low, causing collapse, seizures and coma.

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Treat this as a potential emergency — not a "wait and see" situation.
Contact your vet before symptoms even appear.

US: ASPCA Animal Poison Control (888) 426-4435 · Pet Poison Helpline (855) 764-7661

UK: Veterinary Poisons Information Service 01202 509 000

Why is it dangerous to pets?

Insulin injected or chewed from a pen, and oral drugs such as metformin and glipizide, all lower blood glucose. A pet that has taken too much becomes hypoglycaemic — the brain runs out of fuel within 30 minutes to a few hours.

Pets already on insulin are at extra risk: a double dose or a chewed insulin pen is a common household accident.

Why speed matters

Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.

Symptoms of diabetes-meds poisoning

  • Weakness, wobbliness, staggering
  • Confusion, staring, unusual behaviour
  • Tremors, seizures
  • Collapse, coma
  • Vomiting and drooling before neurological signs

What to do right now

  1. If the pet is awake and able to swallow, offer a small amount of honey, syrup or food and call the vet at once.
  2. Do not put anything in the mouth of a drowsy or seizing pet — it can be inhaled.
  3. Go to the vet; blood glucose needs to be measured and monitored for hours.
  4. Bring the pen or bottle so the dose taken can be estimated.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

Sources & further reading

  • ASPCA Animal Poison Control — pet poison database & dosage references
  • Pet Poison Helpline — toxicology triage guidelines
  • Merck Veterinary Manual — toxicology monographs
  • Vets Now (UK) — emergency toxicosis guidance