Rodenticide exposures have been on the ASPCA Animal Poison Control Center’s Top 10 list for many years and were the top exposure for many states in 2014—and it’s unlikely that pets are going to stop eating them anytime soon.
Often owners are able to 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 a point of making 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 United States baits specifically labeled for mice and rats typically have anticoagulant, bromethalin or cholecalciferol for their active ingredient.
Anticoagulants are still very common, but bromethalin is being seen more often. And in 2015 APCC saw fewer than 20 cases of pets exposed to cholecalciferol.
There are several other toxins that can be used for rodenticides but they are either illegal or have restricted use in the U.S. (sodium fluoroacetate , aldicarb, strychnine) or are marketed as gopher or mole bait (zinc phosphide).
If the exposure is recent and 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 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 U.S. 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: While the least common type of bait, cholecalciferol takes the least amount of bait to be an issue. Besides decontamination, monitoring laboratory tests (calcium, phosphorus, BUN and creatinine) daily for four days after exposure as well as obtaining a baseline is generally advised. Often the pet will be acting abnormal at home (lethargy, anorexia, vomiting) if problems are occurring.