Rodenticide exposures have been on the ASPCA Animal Poison Control Center’s Top 10 list for many years and—and it’s unlikely that pets are going to stop eating them anytime soon.
Often owners can provide information about the brand or type of rodenticide their pet ingested, but how do you proceed when that information isn’t available?
Use What You Know
There are some bits of information that can help you narrow down the type of exposure; however, appearance is not one of them. Unfortunately, manufacturers do not make their bait look different than other brands, nor do they make baits with different active ingredients look different.
So know what is on the market and what it’s used for. In the US, baits specifically labeled for mice and rats typically have anticoagulant, bromethalin, or cholecalciferol for their active ingredient.
Anticoagulants are still very common, but bromethalin and cholecalciferol exposures are seen just as frequently.
Several other toxins may be used illegally for rodenticides, including sodium fluoroacetate , aldicarb, strychnine. Others may have restricted use in the US and be marketed as gopher or mole bait (zinc phosphide).
If the exposure is recent and the pet is healthy, start by decontaminating the pet. This may include inducing emesis and/or activated charcoal. In very large exposures, repeated doses of activated charcoal may be considered; however, this is not a common scenario.
Consider weighing the remaining bait if possible or weighing bait recovered in the vomitus to figure out how much may have been ingested.
Consider Each Possibility
Break down what the concerns and risks would be for each type of bait.
Anticoagulants: Options are to either monitor PT/PTT or start Vitamin K1 therapy. Treat with Vitamin K1 (phytonadione) for 30 days since many of the anticoagulant baits in the US are still second generation.
Bromethalin: While it does take more bait to be a problem in comparison to anticoagulants and cholecalciferol, once signs occur from bromethalin, treatment options are limited. Decontamination (emesis/activated charcoal) to prevent issues are the primary goal with exposures to bromethalin. Attempt to determine amount ingested (remember for a 0.01% bait there will be 2.83 mg of bromethain per 1 ounce of bait) and this chart can be used to help determine how worried you should be. Owners should continue to monitor the pet at home for neurological signs up to four days after the exposure.
Cholecalciferol: Cholecalciferol baits are usually highly concentrated, so it takes a small amount of bait to be an issue. Besides decontamination, monitoring laboratory tests (calcium, phosphorus, BUN and creatinine) daily for 4 days after exposure as well as obtaining a baseline is generally advised. Often the pet will be acting abnormally at home (lethargy, anorexia, vomiting) if problems are occurring.