Anticoagulant and Bromethalin Poisoning in Dogs

There are a variety of rodent poisons on the market, most falling into one of two categories: anticoagulants or bromethalin. Anticoagulants cause internal bleeding while bromethalin is a nerve toxin causing fluid build-up around the brain and spinal cord. Ingestion of either type of rodenticide can be life threatening and requires immediate emergency medical treatment.

Types

Anticoagulant Rodenticides

• High-toxicity anticoagulants (second-generation) are used by and only available to professional exterminators.
• The first-generation anticoagulant products are available to household consumers.
• Anticoagulants prevent blood clotting, causing internal bleeding of all organ systems.
• Anticoagulants work by depleting vitamin K reserves.

Bromethalin Rodenticides

• Bromethalin-containing products are available to household consumers.
• Bromethalin is a nerve toxin.
• Bromethalin causes fluid buildup around and increased pressure on the brain and spinal cord.

Although infrequent, non-target species may ingest poisoned rodent pests and develop relay or secondary poisoning. Whenever a rodenticide exposure is suspected, it's the pet owners responsibility to document the day and time of exposure, brand name and manufacturer, active ingredients, and potential amount consumed. This will aide the veterinarian in immediate treatment.

Symptoms may take anywhere from 2-14 days to appear following ingestion of rodent poison.

Symptoms of anticoagulant poisoning may not be present. Possible symptoms include:

• Weakness
• Low body temperature
• Pale gums
• Difficulty breathing
• Rapid heart rate
• Blood in urine
• Blood in stool
• Bloody nose

Symptoms of bromethalin poisoning in dogs include:

• Decreased appetite
• Decreased thirst
• Pressing head against furniture
• 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.

Rat poisoning may be caused by:

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

If you suspect a pet has gotten into rodent poison or if your pet is demonstrating symptoms of rat poisoning, collect the poison packaging/wrapper that lists the name of the product (and ingredients if possible) and transport your pet to the veterinarian immediately. There is no home treatment for rat poisoning.

The veterinarian will likely place the pet in treatment immediately so nurses can begin supportive care while he takes a thorough history. The veterinarian will want the packaging information from the rat poisoning if available. He will also want to know when symptoms began, when the material was ingested, and how much was ingested.

Unknown Poison Ingestion

If the poison source and amount ingested is unknown, blood testing and urinalysis will help the veterinarian determine the body systems affected. The physical examination can determine the presence of neurological symptoms which can help indicate what type of poison your pet has been exposed to.

Anticoagulant Poison Ingestion

Blood clotting tests (PT and PTT analysis) that demonstrate clotting disruption are suggestive of rat poisoning. The Proteins Induced by Vitamin K Antagonism (PIVKA) test is more specific for detecting rat poisoning.

Bromethalin Poison Ingestion

Bloodwork and urinalysis often do not show signs of bromethalin poisoning. 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 rat poisoning, treatment depends upon the type of poison your pet has ingested.

Anticoagulant Poison Treatment

In the case of poisoning by an anticoagulant rodent poison, the first step is to induce vomiting and administer activated charcoal to bind any residual toxin. Enema may also be administered to clear the bowels. As depletion of vitamin K reserves is the cause of the clotting deficiency, vitamin K will be injected and oral vitamin K will be prescribed for continued treatment at home. Blood transfusion may be required if the patient has experienced significant blood loss. Early diagnosis and treatment for anticoagulant poisoning has a good prognosis.

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

Bromethalin Poison Treatment

In the case of poisoning by bromethalin, the first step is to induce vomiting and administer activated charcoal to bind any residual toxin. Enema may also be administered to clear the bowels. Valium or other medications may be administered to control seizures and muscle tremors.

Supportive therapy will need to continue in the hospital or at home for as long as symptoms continue. Neurological problems as a result of bromethalin poisoning can last for up to 6 weeks post-ingestion.

Prognosis for rat poisoning can be good as long as treatment is administered soon after ingestion. Recovery can take up to 6 weeks for bromethalin poisoning. Recovery of anticoagulant poisoning can be complete in 2-3 weeks with proper treatment.

When purchasing rodent poisons, be sure to keep the packaging available in case of accidental ingestion. Store the product in a safe place out of reach of pets or children. Dispose of dead rodents properly since they contain the poison as well. Choose an anticoagulant over bromethalin since anticoagulant poisons can be countered with vitamin K therapy. If you can, avoid using poisons altogether and use rodent traps instead.