Metformin and Pets
Find out if Metformin is toxic to dogs and cats.
Think your pet ate something toxic?
Call ASPCA Animal Poison Control Center: (888) 426-4435 or view emergency guide
Metformin is a prescription medication used to treat type 2 diabetes in humans and is not safe for dogs or cats. It should never be given to pets without explicit veterinary guidance. Even small amounts can cause significant gastrointestinal upset, and larger overdoses may lead to dangerously low blood sugar (hypoglycemia) or lactic acidosis, a life-threatening buildup of acid in the blood.
Pets are usually exposed when they chew or swallow dropped pills, pill bottles, or pill organizers left within reach. Extended-release tablets are especially concerning because they can release a large amount of medication over time as they pass through the digestive tract. Dogs may also be accidentally dosed by well-meaning owners who mistake human medications for veterinary treatments.
Signs of metformin poisoning may appear
Is Metformin Toxic to Dogs?
Metformin can cause vomiting, diarrhea, lethargy, and hypoglycemia in dogs; large overdoses may lead to lactic acidosis and require emergency care.
Is Metformin Toxic to Cats?
Metformin is toxic to cats and can cause severe hypoglycemia, vomiting, diarrhea, and lactic acidosis; even small amounts warrant veterinary attention.
Active Ingredients
- metformin hydrochloride
Common Brand Names
- Glucophage
- Fortamet
- Glumetza
- Riomet
Dosage Form
tabletextended-release tabletoral solution
Common Uses
- Type 2 diabetes mellitus in humans
- insulin resistance
- polycystic ovary syndrome (PCOS)
Toxic Ingredients
- metformin hydrochloride
Symptoms to Watch For
- vomiting
- diarrhea
- lethargy
- weakness
- hypoglycemia
- tremors
- seizures
- decreased appetite
- abdominal pain
- rapid breathing
- lactic acidosis
What If My Pet Was Exposed to Metformin?
Contact your veterinarian or a pet poison helpline immediately. Do not induce vomiting unless instructed. If ingestion was recent, your vet may advise decontamination and monitoring of blood glucose and lactate. Bring the medication bottle to the clinic.
Sources
Vet's Note
PetPilot provides general information for educational purposes. While we reference authoritative veterinary organizations, this page has not been individually reviewed by a veterinarian for your specific pet. Individual animals may react differently based on age, weight, breed, health conditions, and amount consumed. Always consult your veterinarian or a poison control center for personalized advice, especially if your pet is ill, injured, pregnant, nursing, or on medication.