Anticoagulant and Bromethalin Poisoning in Dogs

Rodenticides are poisons used to kill rats and mice. There are a variety of rodent poisons on the market, many of which fall into 1 of 2 categories: anticoagulants or bromethalin-based products. Anticoagulants cause internal bleeding in rats and mice, while bromethalin is a nerve toxin causing swelling of the brain.

Ingestion of either type of rodenticide can be life-threatening for your dog and requires immediate emergency medical treatment. If you suspect that your dog has consumed any type of rat or mouse poison, seek veterinary attention straight away.

Types

Anticoagulant rodenticides are split into 2 categories. First-generation anticoagulants (such as warfarin) tend to be short-acting, while second-generation anticoagulants (such as brodifacoum) are longer-lasting and can only be used in the United States by professional exterminators. Anticoagulants prevent blood clotting, causing internal bleeding.

Bromethalin is a neurotoxin that causes brain swelling. Bromethalin-based rodenticides are available to household consumers and are available in block, pellet, bar, and worm form.

The symptoms of rodenticide poisoning in dogs vary depending on the type of poison your pet ingests. In cases of anticoagulant poisoning, symptoms may take several days to develop and could include:

• Weakness
• Depression
  
• Pale gums
• Difficulty breathing
• Coughing
• Rapid heart rate
• Loss of appetite
• Swollen abdomen
• Bruising
  
• Blood in urine
• Blood in stool
• Bloody nose

In cases of bromethalin poisoning in dogs, symptoms can develop within 2 hours if your pet ingests a large dose, but may take as long as 4 days to develop if a smaller dose has been consumed. Symptoms include:

• Decreased appetite
• Vomiting
• Lethargy
• Weakness
  
• Circling
• Impaired movement
• Hind limb paralysis
• Muscle tremors
• Seizures

A variety of rodent poisons are available on the market and all should be considered life-threatening if ingested.

Anticoagulant and bromethalin rodenticide poisoning may be caused by:

• Ingestion of rodent poison
• Ingestion of a rat or mouse that has consumed rodent poison

However, the way in which a rodenticide affects your pet varies depending on the type of poison consumed. Anticoagulants inhibit the production of vitamin K1, which is essential for normal blood clotting. Without enough vitamin K1, uncontrolled bleeding can result. Meanwhile, bromethalin is a neurotoxin that affects oxygen supply to the brain and causes swelling of the brain (cerebral edema).

Both types of rodenticide have the potential to be fatal to dogs, so it's vital to seek urgent veterinary attention.

If you suspect your dog has ingested any rodent poison, or if your pet is showing symptoms of poisoning, seek immediate veterinary attention. Take any packaging with you so that your vet knows the type of rodenticide your pet has consumed and its active ingredient.

Your vet will want to know how much rat poison your pet has ingested, how long ago, and when symptoms began (if they have already begun). Treatment will begin straight away, but the treatment method will vary depending on the type of poison consumed.

Unknown poison ingestion

If the poison source and amount ingested are unknown, blood testing (including a clotting profile) and urinalysis will help your vet determine the bodily systems affected. A physical examination can also help determine the presence of neurological symptoms, which can help indicate what type of poison your pet has been exposed to.

Anticoagulant rodenticide ingestion

Your vet will conduct a full physical exam and use blood tests to determine your pet's red blood cell and platelet count, and how effectively their blood is clotting. Imaging techniques such as x-rays and ultrasound may also be used to check for signs of internal bleeding.

Bromethalin rodenticide ingestion

Bloodwork and urinalysis often do not show signs of bromethalin poisoning. If your pet is showing signs of bromethalin poisoning and you know or suspect that they've been exposed to this type of rodenticide, this will be enough for your vet to begin treatment.

If neurological symptoms are present, a brain scan using magnetic resonance imaging (MRI) or computerized tomography (CT) scan can help visualize fluid buildup around the central nervous system.

If your pet is diagnosed with rodenticide poisoning, treatment depends upon the type of poison they have ingested.

Anticoagulant poisoning treatment

In the case of poisoning by an anticoagulant rodenticide, the first step is to induce vomiting (if it has been four hours or less since ingestion) and administer activated charcoal to bind any residual toxin. 

The good news is that there is an antidote for anticoagulant rodenticide poisoning. As the depletion of vitamin K reserves is the cause of clotting problems in dogs, vitamin K will be injected and oral vitamin K will be prescribed for continued treatment at home.

Some dogs will require hospitalization and IV fluids. A blood transfusion may be required if your dog has experienced significant blood loss, and oxygen therapy may also be given in severe cases.

Follow-up blood tests may be necessary to ensure internal bleeding is no longer an issue and to monitor the replenishment of clotting factors in the blood. When clotting factors have returned to normal, vitamin K therapy can be discontinued.

Bromethalin poisoning treatment

In the case of poisoning by bromethalin, there is no antidote. To maximize your pet's chances of a successful recovery, treatment must begin as soon as possible after they ingest the rodenticide.

The first step is to induce vomiting and administer activated charcoal to bind any residual toxin. Medications may be administered to decrease brain swelling and to control seizures and muscle tremors.

Supportive therapy will need to continue in the hospital or at home for as long as symptoms continue. 

The prognosis for anticoagulant rodenticide poisoning can be good as long as treatment is administered soon after ingestion. However, your dog will need to be given vitamin K pills for several weeks following poisoning.

The treatment of, and recovery from, bromethalin poisoning is more complicated. Neurological problems as a result of poisoning can last for weeks post-ingestion, and may be permanent in some cases. Your dog may also experience appetite loss for an extended period of time, so ongoing feeding support may be required.

It's important to take steps to prevent your dog ingesting any rat or mouse poisons. Make sure any rodenticides around your home are kept well out of reach of pets and children, and dispose of any dead rodents promptly and properly. If possible, avoid using poisons altogether and use rodent traps instead.

Anticoagulant and bromethalin poisoning can be expensive to treat. If you suspect your dog is at risk of poisoning, start searching for pet insurance today. Wag!’s pet insurance comparison tool lets you compare plans from leading companies like PetPlan and Embrace. Find the “pawfect” plan for your pet in just a few clicks!