In the chilly winter months, rodenticide toxicity is a serious concern for pets. As small rodents head indoors in search of warm housing, homeowners are tempted to set out baits to get rid of the pests, no matter the cost. Unfortunately, pets can easily sniff out a bait that is not securely hidden, and be poisoned. They can also be poisoned if they eat a mouse or rat that ate the bait and died.
If your pet is poisoned, knowing the rodenticide type they ate is critical for treatment, and early intervention offers the best prognosis. Protect your pet by learning about the various rodenticides, how they work, and the toxicity signs.
Types of rodenticides
Four main rodenticides types your pet may ingest are concerning—anticoagulants, bromethalin, cholecalciferol, and zinc phosphide. Each has a different mechanism of action and a wide range of signs can be seen. Left untreated, rodenticide toxicity of any type can be fatal, so knowing the type your pet ingested will ensure they receive proper treatment.
Anticoagulant rodenticides, the most common type, contain warfarin or other compounds that interfere with blood clotting. They vary in toxicity level, with some highly toxic with only a single feeding, and others only toxic after multiple feedings. Pets can be poisoned directly from eating baits, or from eating poisoned rodents.
Poisoned pets display signs associated with blood loss, such as anemia and bleeding into various body areas (e.g., the gastrointestinal [GI] tract, eyes, nose, lungs, or urine). Affected pets can become weak, lack coordination, and breathe rapidly. Depression and anorexia are typically seen before bleeding occurs.
A pet who receives vitamin K treatment shortly after ingesting an anticoagulant rodenticide, before blood loss is severe, typically has a good prognosis. They may need Vitamin K for two to four weeks, and should be fed the vitamin with a fatty meal to improve absorption. Blood clotting values must be monitored throughout treatment, and then checked post-treatment to ensure they remain normal.
The next most common rodenticide, bromethalin causes brain swelling. Signs including vomiting, depression, loss of coordination, tremors, and reluctance to stand can take one to four days to develop, if your pet ingested a small amount. Higher dosages can result in rapid onset of hyperexcitability, muscle tremors, seizures, heightened hind limb reflexes, central nervous system depression, and death about 10 hours after ingestion.
Immediate treatment is essential to reduce brain swelling, so your pet needs emergency care if you suspect they ate bromethalin rodenticide. Treatment focuses on blocking poison absorption, and reducing brain swelling that has already occurred.
Cholecalciferol (i.e., vitamin D₃) rodenticides are the third most common type and only a little can be toxic because they are highly concentrated. This rodenticide produces excess calcium in the blood, resulting in calcification (i.e., hardening) of the soft tissues, such as the blood vessels, heart, and kidneys, throughout the body.
Signs generally develop 18 to 36 hours after ingestion and can include depression, anorexia, excessive urination, and excessive thirst, as well as bloody vomit and diarrhea, as kidney damage progresses. Treatment involves inducing vomiting to remove the rodenticide, followed by decontamination through activated charcoal administration. Pets should be fed a low-calcium diet, and their blood calcium levels should be monitored following treatment.
Zinc phosphide rodenticide
Zinc phosphide is a rodenticide meant for outdoor use to kill gophers and moles that converts to phosphine gas in the stomach when ingested. The gas irritates the gastrointestinal (GI) tract and first causes vomiting and abdominal pain. Next, nervous system signs, such as stumbling, tremors, and seizures, develop. Cardiovascular collapse can also occur, followed by death from respiratory arrest. Treatment focuses on neutralizing stomach acidity and supportive care.
The phosphine gas is also toxic to people, so if your pet vomits after ingesting this rodenticide, and you are exposed, contact a human poison control center.
What should I do if my pet gets into rodenticide?
Whether or not you are certain that your pet ingested rodenticide, treatment is always recommended after exposure. Since rodenticides cause fast-acting toxicity, immediate care is crucial for a good prognosis. If possible, find the product packaging so you know the type and amount of rodenticide type.
Contact an animal poison control hotline to determine next steps, and then head to your nearest emergency veterinary hospital or Creature Comforts Veterinary Service. Give us a call before heading to our hospital, so we are prepared for your pet’s arrival and can administer the appropriate treatment as soon as you arrive.