Anticoagulant Rodenticide Toxicity in Pets
Overview
Rodenticides (rat and mouse poisons) are commonly used to control pests—but they’re also one of the most dangerous household toxins for dogs and cats. There are several different types of rodenticides, and they don’t all work the same way. Some affect the brain, others the kidneys, and some, like anticoagulants, disrupt the blood's ability to clot.
This article focuses specifically on anticoagulant rodenticides, which are among the most common and most treatable—if caught early.
Why Anticoagulant Rodenticides Are Dangerous
Anticoagulant rodenticides interfere with vitamin K recycling in the body. Without vitamin K, the body cannot produce clotting factors, leading to uncontrolled internal bleeding. These poisons don’t act immediately—signs often appear several days after ingestion, which can make diagnosis tricky.
Rodenticides are very dangerous to pets.
Common Products That May Contain Anticoagulants:
D-Con
Tomcat Mouse Killer
Havoc
Warfarin, Brodifacoum, Diphacinone, and similar ingredients
Symptoms of Anticoagulant Rodenticide Toxicity
Signs are usually delayed for 2–3 days and can include:
Lethargy
Coughing or difficulty breathing (from chest bleeding)
Pale gums
Weakness or collapse
Nosebleeds or bleeding from gums
Vomiting or diarrhea with blood
Swollen joints or bruising under the skin
Severity Based on Amount Ingested
Even small amounts can be dangerous, especially in cats and small dogs. Pets with liver disease, poor nutrition, or other clotting issues are at even greater risk. Severity depends on the type of anticoagulant and how much was consumed.
What to Do If Your Pet Is Exposed
Call Animal Poison Control Immediately. Don’t wait for symptoms. The delay in onset can be deceptive. ASPCA Animal Poison Control: 888-426-4435
Save the product label if possible. The exact type of poison matters.
Do not induce vomiting unless directed. Some products can cause additional harm if not handled properly.
Treatment:
Many cases of ingestion require veterinary intervention. If caught early, options are good for sending home with an antidote. If not addressed on time, hospitalization is often needed.
Inducing vomiting (if early and appropriate)
Administering vitamin K1 (antidote) for 2–4 weeks
Blood tests to monitor clotting function
Blood/ plasma transfusions if severe bleeding has occurred and treatment wasn’t initiated.
Prognosis
If caught early and treated with the correct vitamin K protocol, prognosis is excellent. However, untreated anticoagulant toxicity can be fatal.
Prevention Tips
Avoid using rodenticides in or around the home if you have pets
Use pet-safe traps instead of poison
Keep all pest control products locked away
Inform guests, landlords, or pest control professionals about your pets
Final Thought
Rodenticides are silent but deadly. Anticoagulant versions are treatable, but only if you act fast. Know the risks and keep your pet safe.
Having some familiarity with the most common toxins ingested by pets is vital to being prepared for emergencies. While we all prefer to avoid emergencies, they do happen and being prepared for them can make a big difference in the outcome. Check out our Dog Owner’s Guide to Health Emergencies book, to learn more about emergency preparedness, the top 10 veterinary emergencies, the top 10 toxicities and more.
