Sep 28, 2011 – Muncha Buncha Rattus


If a cat or a dog chews on a dead rodent poisoned by bait blocks is the pet in danger from the poison?


Here's the reality of a situation like this. You may be between that rock and a hard place. While a dog or cat simply "chewing on" or licking a rodent that has died from rodent poison really is not going to ingest an amount of the active ingredient that could possibly be dangerous to it, the pet's owner is likely to be paranoid, and demand that you pay for a vet bill for some treatment. If the dog or cat did not completely consume the rodent, stomach, intestines, and all, then it's probably that the dog did not even consume any rodent bait, although if it managed to swallow some of that rodent's blood I suppose technically it also swallowed whatever amount of active ingredient already was in the blood of that rodent.

But, it is all based on weight - the weight of the animal compared with the amount of rodent bait consumed, and a rat or mouse requires many times less bait to kill it than a dog or cat would. For example, Lipha Tech has an excellent "Veterinarians Guide" available on their website that EVERY pest control company should have on site, and probably should consider providing to all the veterinarians in their area. This guide lists the "probable" quantities of bait product for each of the active ingredients of the anticoagulants that would be considered a lethal dose for dogs (22 lb) or cats (4.4 lb). For example, a 22 lb dog would have to CONSUME from 6.2 to 105 ounces of diphacinone bait, 77 to 141 ounces of bromadiolone bait, or 1.8 to 25 ounces of brodifacoum bait. Even the lowest amounts listed here would be tremendous amounts to expect to find in a single rat, much less a mouse. And, the entire rodent would have to be swallowed to get all the remaining bait in that rodent into the system of the dog or cat. This is a very unlikely scenario.

Is this kind of secondary poisoning "possible". Well, certainly it is possible. The rat might have been a glutten that ate every scrap of rodenticide it could find, or the dog might have found a couple dozen rats that all had been gluttens and the dog ate every last one of them. But, these things are highly unlikely. It could be more likely with a rat, where an adult rat can consume up to 30 grams (about 1 ounce) of bait per day, whereas a mouse tops out at about 4 grams. As Dr. Robert Corrigan states it in his book "Rodent Control" - secondary poisoning in which a dog or cat consumes a dead rodent is "theoretically possible but is highly unlikely".

So, if this cat or dog only found a single rodent and chewed on it awhile without swallowing all of it, particularly its internal organs, it would be very, very unlikely that the pet ingested even any of the toxicant, much less a hazardous amount. If that pet is in the habit of finding and consuming multiple dead rodents then a trip to the vet definitely is warranted, and the veterinarian can take blood samples and treat for anticoagulant poisoning as he sees warranted.

The other consideration is that dead rodents should never be left lying around, whether in traps or killed by bait. In fact, rodenticide labels universally state that we are to "collect and dispose of all dead, exposed animals and leftover bait". If we are contracting with a customer to do the rodent control for them this mandates that the dead rodents must be found and removed, and once we are finished with that job all remaining bait also must be removed. It would be illegal for us to do a one-shot for rodent control using bait in or around a home.

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