Activated charcoal, when used judiciously, is a very useful way to treat pets who are exposed to toxins. And one of the times to be most aggressive with activated charcoal is when a pet is exposed to a bromethalin rodenticide. Compare your treatment strategy with this hypothetical case study and see how your procedure measures up.
While home alone, Oscar, a 7 kg Miniature Dachshund, finds all five of the 0.5 ounce blocks of bromethalin his owner had set out in the house that morning to deal with a mouse problem.
Oscar presents at your hospital, having ingested the toxin sometime in the past six hours. He is BAR and exam is wnl. You examine the packaging and see that the blocks are 0.01% bromethalin and calculate that his dose with the 2.5 ounces is 1 mg/kg of bromethalin. You induce emesis and recover a small amount of bright blue-green bait, but not a significant amount.
What’s The Next Step?
1. Inform the owners that as long as Oscar is passing this in his stool in the next 24 hours, no further treatment is needed.
2. Start Oscar on 1.5-2.5 mg/kg of Vitamin K1 PO BID for 30 days and send him home.
3. Inform the owners that since a high dose of bromethalin is involved, decontamination to prevent neurotoxic signs must be aggressive. Give Oscar a dose of 10-20 ml/kg of activated charcoal with sorbitol and send him home with doses for the owner to give every six hours for the next three days. Counsel the owners to make sure he has access to water.
4. Inform the owners that since a high dose of bromethalin is involved, decontamination to prevent neurotoxic signs must be aggressive. Obtain baseline electrolytes and give Oscar a 3-5 ml/lb dose of activated charcoal with sorbitol. Repeat a half dose of activated charcoal without sorbitol every eight hours for the next 48 hours. (Oscar can receive a half dose without sorbitol at the fourth dose to help facilitate the passage of the activated charcoal.) He should be in the hospital on fluids, and baseline electrolytes should be obtained and rechecked before every dose of activated charcoal or if the signs of hypernatremia occur. If the sodium is high or has jumped 5 points (especially if he is symptomatic), the activated charcoal should be stopped and Oscar should be treated for hypernatremia.
The best answer is 4. This would be appropriate use of activated charcoal. Given the size of the pet and number of doses of activated charcoal he will be given, fluids and close monitoring of serum sodium levels is appropriate.
Option 1 is not appropriate because even as the color of the bait has passed, the toxin has been absorbed and the potential for toxicity is still present.
Option 2 is not appropriate, as this neurotoxin is not treated with Vitamin K1.
Option 3 is not appropriate, as Oscar needs to be on fluids and monitored for hypernatremia in a hospital setting. Additionally, giving multiple doses with sorbitol will not only increase the risk of hypernatremia, it will also probably give the pet significant diarrhea.