Rodenticides are one of the most common toxin exposures we see in veterinary medicine. Last month I covered anticoagulant rodenticides, which are the easiest to treat. Now we will touch base on the other two classes of rodenticides—cholecalciferol and bromethalin. These two types of rodenticides are not easy to treat like the anticoagulants. These are newer generation poisons that can cause serious harm to pets if not treated quickly.
Cholecalciferol may sound like a familiar word to some people because it is the medical name for Vitamin D3. Most people have Vitamin D3 in their homes for themselves. While it is a great supplement for people, it can be tremendously toxic to cats and dogs. When a dog or cat ingests cholecalciferol, it causes extreme elevation in calcium and phosphorus levels. Because their calcium is so high, their tissues will start to mineralize, which can cause organ damage, particularly to the kidneys. Cholecalciferol is a fat-soluble vitamin, meaning it is stored in fat and takes longer to clear from the body.
Much like the anticoagulant rodenticides, we often start by making the dogs vomit. That way we can get as much of the toxin out of their system as possible before it can be absorbed. With this type of rat poison, it is recommended we administer activated charcoal. This helps to bind the toxin so it can move through the gastrointestinal tract without absorption. Cholecalciferol often requires multiple doses of activated charcoal.
We recommend monitoring bloodwork, particularly tracking calcium, phosphorus and kidney enzyme levels with this type of toxin exposure. This often means daily bloodwork for 2–3 days while the patient is receiving intravenous fluids to help protect the kidneys. If calcium or phosphorus levels are increasing, we will start medications to bind the calcium and phosphorus. In most cases, if care starts early, we do not see long-term effects from the toxin. If we do not act fast, we can see kidney failure.
Bromethalin is a neurotoxin. While dogs must eat a larger amount to cause symptoms. If those symptoms start, there is little we can do to help them. We may see paralysis, seizures, tremors and hyperexcitability. According to published research, clinical signs generally start 2-12 hours after ingestion and “virtually always result in rapid deterioration and death.” I strongly urge not keeping rodenticides in the home if you have pets, but if you need to, please do not use any in the bromethalin class.
In the next issue, I’ll discuss the most well-known toxin for dogs, chocolate!