Rodenticides have long been used for population control of mice, rats and other rodents. Historically, anticoagulant baits have been most popular. Anticoagulants cause inhibition of blood clotting, leading to excessive, fatal bleeding. In 2013, the EPA banned anticoagulant rodenticides in an attempt to decrease toxicity to children, pets and wildlife. A phase out program was initiated. By 2015, companies were no longer able to manufacture or distribute these type of rodenticides. Stores that had remaining stock are able to sell the product until the supply was completely depleted. Now, these products are no longer commercially available but may be found in may homes from previous purchases.
This is important because not all rodenticides are the same or carry the same risks. While the anticoagulant rodenticides carried a high toxicity, an antidote was widely available. The newer products have require a large dose for toxicity to occur but no antidote is available. Because of this, if you use any rodenticides, it is extremely important that you know which product you are using, keep your pet away from the product and if they do ingest some, seek veterinary attention immediately.
The most commonly used rodenticides fall into the following categories:
Anticogulants - warfarin, brodifacoum, bromadiolone, diphacinone
Clinical signs include bleeding, pale gums, weakness, exercise intolerance, coughing, swollen joints, lameness, etc.
Clinical signs can be delayed by 2-3 days post ingestion.
Treatment: Vitamin K, in severe cases hospitalization and blood transfusions may be necessary.
Bromethalin
This product is a neurotoxin that stops cells in the brain from producing energy. This causes the nerves to swell which puts pressure on the brain leading to clinical signs.
Clinical signs may be occur 24 hours to 2 weeks post ingestion.
Clinical signs include muscle tremors, seizures, hyperexcitability, ataxia (incoordination), central nervous system depression, weakness, paralysis and death. Prognosis is poor is severe clinical signs are present.
There is NO antidote for this product.
Treatment is supportive and includes decontamination of the stomach and supportive care.
Cholecalciferol Based Rodenticides
This product causes too much calcium to be absorbed from the kidneys and gastrointestinal tract resulting in too much calcium in the blood. This can lead to kidney failure, heart abnormalities, central nervous system abnormalities and tissue mineralization.
Clinical signs include vomiting, diarrhea, depression, marked increased water consumption and urination, heart arrhythmias, and weakness. Permanent kidney and muscle damage persist in patients that survive.
Treatment is extensive and may be required for several weeks. Treatment includes aggressive decontamination,IV fluid support for kidneys, drugs to inhibit bone resorption and other supportive care.