Warfarin and Pets
Find out if Warfarin 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
Warfarin is a prescription blood thinner used in humans and is extremely dangerous to dogs and cats. Even a small amount can interfere with blood clotting and cause internal bleeding that may not be obvious for hours or even days. Because pets are much smaller than people and metabolize medications differently, a dose that seems minor can be life-threatening.
Exposure usually happens when a pet eats a dropped pill, chews through a medication bottle, or consumes food containing warfarin. Dogs are especially at risk because they may swallow entire pill vials or tablets found on counters, nightstands, or in bags. Cats can also be poisoned if they lick up spilled tablet fragments or powder, or if they are given human medication by mistake.
Early signs of warfarin poisoning can be subtle and include weakness, lethargy, pale gums, and bruising. More serious symptoms include coughing blood, bloody urine or stool, bleeding gums, collapse, and difficulty breathing. Because bleeding may be internal and hidden, any suspected ingestion should be treated as an emergency.
Keep all warfarin and other human medications in a closed cabinet well out of reach. Never give your pet any human blood thinner, and clean up dropped pills immediately. If your pet needs anticoagulant therapy, ask your veterinarian about safe, veterinary-approved alternatives.
Is Warfarin Toxic to Dogs?
Warfarin is a potent anticoagulant that causes life-threatening internal bleeding in dogs, even at small doses.
Is Warfarin Toxic to Cats?
Warfarin is highly toxic to cats and can cause severe internal hemorrhage with only a small exposure.
Active Ingredients
- warfarin
Common Brand Names
- Coumadin
- Jantoven
Dosage Form
tablet
Common Uses
- anticoagulation
- prevention of blood clots
- treatment of thromboembolic disease
Toxic Ingredients
- warfarin
Symptoms to Watch For
- weakness
- lethargy
- pale gums
- coughing blood
- bloody urine
- bloody stool
- bleeding gums
- bruising
- collapse
- difficulty breathing
What If My Pet Was Exposed to Warfarin?
If your pet may have ingested warfarin, contact your veterinarian or a pet poison helpline immediately. Do not wait for symptoms. Bring the medication container to the clinic. Treatment may include inducing vomiting, activated charcoal, vitamin K1 therapy, and supportive care.
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.