Anticoagulant Toxicity in Cats

 

Although designed to kill rats and mice, cats often find rodenticides (rat and mouse poison) tempting as well. Most (but not all) rodenticides are composed of anticoagulants, a type of drug that prevents blood from clotting by interfering with vitamin K, a key ingredient in the clotting process. When taken in sufficient quantities by the cat, it results in spontaneous bleeding (internal bleeding, external bleeding, or both). If left untreated, this could prove fatal for your cat.

 

What to Watch For

 

Typically, it takes 2 to 5 days for the following symptoms associated with anticoagulant poisoning to appear:

 

• Bruising
• Pale gums
• Blood in urine, vomit, feces
• Bleeding from gums, nose, rectum, eyes, ears
• Weakness, staggering gait, depression
• Blood accumulation in the chest (hemothorax), which may lead to shallow or labored breathing
• Blood accumulation in the abdomen (hemoabdomen), which may cause the abdomen to distend

 

Primary Cause

 

Cats can ingest toxic doses of anticoagulants by eating rodenticide left on the ground or by eating a rodent that has ingested rodenticide. There are many forms of anticoagulant used in rodenticides; some of the more common forms are warfarin, brodifacoum, bromadiolone.

 

Immediate Care

 

• Call your veterinarian, the nearest animal hospital or the Pet Poison Helpline at at 1-855-213-6680, especially if you notice your cat is bleeding.
• If you can find the container or label for the poison, bring it with you to the veterinarian.

 

Veterinary Care

 

Diagnosis

 

If you should witness your cat eating rodenticide or see pieces of rat poison in her vomitus, anticoagulant poisoning is a near certainty. Otherwise, if your cat should start bleeding without cause, your veterinarian will conduct blood tests to determine if the time it takes for the blood to clot is abnormally long.

 

However, blood tests should not be the only determining factor for diagnosis, as the clotting time for a cat that has only recently ingested anticoagulants is normal, only to gradually worsen until the point where the blood can no longer effectively clot.

 

If there is uncertainty about whether the symptoms are due to an anticoagulant, your veterinarian will do additional tests to make that determination.

 

Treatment

 

If the anticoagulant is suspected to have been ingested within the past two hours, and if you have not already done so, your veterinarian will induce vomiting. Activated charcoal is given orally within 12 hours after ingestion of the poison to absorb any of the toxin that may still be in the intestines.

 

Vitamin K is also given by injection, followed by 1 to 4 weeks of vitamin K tablets given orally at home. The length of the prescription is determined by the type of anticoagulant.

 

If your cat is actively bleeding, he will be hospitalized and monitored until the bleeding stops. If blood loss is severe, your cat may require intravenous fluids or a blood transfusion. There may be a need for special treatments if other problems should arise. For example, if there is bleeding into the chest, that blood will need to be drained so the cat can breathe easier.

 

Other Causes

 

Human medications that contain anticoagulants, like Coumadin® and other blood thinners, are a potential source of anticoagulant poisoning.

 

Living and Management

 

Once your cat is stable, she will be sent home with a vitamin K prescription to be given orally. It is best to give it with canned food, as the fat in the food will help it to be absorbed. It is also important for your cat to get the full course of vitamin K prescribed, even if she seems fine. It often takes a while for certain anticoagulants to be eliminated from a cat's body. Your veterinarian will schedule follow-up tests to monitor your cat’s blood count and clotting time.

 

Please note: The vitamin K your veterinarian prescribes is in a highly concentrated form. The vitamin K you can buy over the counter is only a small fraction of the strength needed and will not be enough to help your cat.

 

Prevention

 

It is best not to use rodenticides if you have pets or young children in your home. There are other products that can control rodents without the use of poison. Your cat may even be willing to help with the rodent control.

 

In addition, since you have no control over how your neighbors eliminate rodents, it is best not to let your cat outside unsupervised.