Rodenticide Toxicity in Dogs

Rat and mouse poisons, or rodenticides, are commonly used in homes and on farms right around the country to kill disease-carrying pests. Unfortunately, rodenticides are highly toxic to dogs and can potentially be fatal, so it's vital to seek immediate veterinary attention if your pet ingests any rodenticide or consumes an animal that was previously poisoned.

There are several different types of rodent poison on the market, and they each affect dogs in different ways. While some cause excessive bleeding, others cause kidney failure or even brain swelling. With this in mind, taking rodenticide packaging with you to the vet is vital to help your veterinarian determine the active ingredient in the poison and make an accurate diagnosis.

The symptoms of rodenticide poisoning vary depending on the type of rodenticide ingested and the effects it has on your pet. Some of the symptoms that may indicate internal hemorrhaging/bleeding can include:

• Difficulty breathing or rapid breathing
• Depression
• Weakness
• Lethargy
• Bloody vomiting
• Blood in urine
  
• Blood in stool
• Pale gums
• Abdominal swelling
• Coma

Symptoms that may be a sign of kidney failure are:

• Increased thirst
• Frequent urination and/or urinary incontinence
• Decreased appetite
• Oral ulcers
• Bad breath

Symptoms that could occur due to a deteriorating nervous system are:

• Lethargy
• Decreased or lack of appetite
• Stumbling, falling, clumsiness and lack of coordination
• Muscle spasms or tremors
• Paralysis
• Seizures
• Coma

However, if you know or suspect that your pet has ingested rat poison, don't wait for symptoms to develop. Rodenticide poisoning is a life-threatening situation, and early treatment is vital to improve your dog's chances of making a full recovery.

Rat bait toxicity can occur directly when a dog consumes rodenticide, or if they ingest an infected rodent that has been hunted and killed (this is known as relay toxicosis).

Different poisons affect dogs in different ways. Let's take a closer look at some of the most common types of rodenticides and how they can impact your pet.

Anticoagulants

Anticoagulants reduce your dog's levels of vitamin K1, which is essential for normal blood clotting. Once the blood is unable to clot, uncontrolled bleeding occurs and can be fatal if left untreated.

There are 2 categories of anticoagulant rodenticides: first-generation and second-generation. First-generation anticoagulants typically have a shorter half-life and include:

• Chlorpophacinone
• Diphacinone
  
• Warfarin

Second-generation anticoagulants are longer-lasting but are no longer available in products for consumer use in the USA. Examples of this type of rodenticide include:

• Bromadiolone
• Brodifacoum
• Difenacoum

The main danger of anticoagulants is that it can be several days after ingestion before your dog starts showing any symptoms, by which time severe poisoning may have occurred. Find out more in our guide to anticoagulant and bromethalin poisoning.

Bromethalin

Bromethalin is a common ingredient in rodenticide bait stations for the consumer market. This neurotoxin causes swelling of the brain (cerebral edema) and can be life-threatening. Symptoms of bromethalin toxicity can develop in as little as 2 hours if your dog has consumed a large dose, but it may take a few days for your dog to show clinical signs in other cases.

Cholecalciferol

Cholecalciferol is a form of vitamin D (vitamin D3) and is an increasingly popular ingredient in rodenticides. It's absorbed rapidly and causes hypercalcemia (abnormally high calcium levels) and  hyperphosphatemia (abnormally high phosphorus levels) in your dog's blood. This leads to kidney failure, so cholecalciferol toxicity requires urgent treatment. Find out more in our guide to cholecalciferol poisoning in dogs.

Zinc and aluminum phosphides

When ingested by your pet, zinc and aluminum phosphides react with stomach acid to produce phosphine gas. This toxic gas is highly dangerous to pets as well as humans, and can cause abdominal pain, liver and lung damage, and potentially death in dogs.

Strychnine

Used in products designed to kill gophers, moles, and rats, strychnine is a highly toxic poison and very dangerous to dogs. If ingested, it can produce clinical signs in as little as 15 minutes and causes muscle contractions, severe seizures, and sudden death.

If your pet ingests any type of rodenticide, seek veterinary attention straight away. If possible, take any product packaging with you so that your veterinarian knows which toxic compound(s) your pet has ingested and the amount consumed.

The vet will physically examine your dog, and screen for suspected ingredients in vomit samples. Blood tests (haematology and biochemistry) and urinalysis will be done, to check for any organ damage or inflammation. They may also test the blood’s ability to clot, use a PIVKA (Proteins Induced by Vitamin K Antagonism) test to determine anticoagulant poisoning, or perform a A-FAST ultrasound scan to check for hemorrhaging.  

No matter which type of rodenticide is involved in poisoning, it's vital to seek veterinary attention as soon as possible. However, the treatment of rodenticide toxicity in dogs varies depending on the type of poison ingested.

In cases of anticoagulant rodenticide toxicity, the good news is that there is an antidote. After decontamination steps including inducing vomiting and administering activated charcoal have been taken, vitamin K injections will be given and oral vitamin K will be prescribed for continued treatment at home. If your pet has a low red blood cell count and is considered to be anemic, a full blood transfusion may be necessary, while oxygen therapy may also be required in some cases.

Unfortunately, there is no antidote for bromethalin toxicity. Decontamination to remove toxins from the body is the first step of treatment, with medications given to reduce brain swelling and control your dog's seizures and tremors.

For cholecalciferol poisoning, if the pet is stable, your veterinarian will induce vomiting and administer activated charcoal to remove the toxins,  with hospitalization and fluid therapy needed in severe cases. Saline fluid therapy is used as it does not contain calcium. Diuretics such as Furosemide may be given, to increase calcium excretion. Bisphosphonates or calcitonin are given to severely affected animals. Phosphate binders and a low calcium, low phosphorous diet is also advised. 

In cases of poisoning involving zinc and aluminum phosphides, decontamination is followed by fluid therapy and supportive care. Antacids can be used to reduce the amount of toxic gas produced, while antioxidant therapy, gastroprotectants, and anticonvulsant medications may also be given.

Prompt treatment is vital to maximize your dog's chances of a full recovery from rodenticide toxicity. However the exact recovery time and ongoing management required varies depending on the poison involved and the severity of poisoning.

After anticoagulant poisoning, for example, your dog may need to be given vitamin K for weeks following poisoning, while the neurological signs of bromethalin poisoning can also last weeks and may even be permanent. Check out our poisoning guides for each type of rodenticide mentioned in this article — you'll find the links in the "Causes" section higher up the page — for more detailed information on the treatment, recovery, and management or rodenticide toxicity.

Rodenticide toxicity can be expensive to treat. If you suspect your dog is at risk of rodenticide 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!