- Dr. Monica Sterk
- Feb 14, 2024
- 6 min read
Updated: Sep 5
Oh rats! Adorable in an animated movie but in real life, if it’s not your pet rat, they're a problem. Rats can carry disease and destroy wiring, drywall, and other essential parts of your home. From countryside to city living, humans have a rat population problem we try to control. That means exterminators are setting traps, which can be dangerous—and even fatal—to pets.
TYPES OF RODENTICIDES (RAT POISONS) AND THE TOXICITY TO PETS
There are plenty of rodenticides (the fancy name for rat poisons) on the market that are effective. However, many of these contain ingredients that are highly toxic to dogs and other pets.
It’s imperative that you take your pet to the vet immediately if you suspect he or she has ingested any kind of rat poison, and not wait for symptoms to appear, which can be hours or days later after irreparable damage is done. Here’s what you should know about common rat poisons and your pet.
CHOLECALCIFEROL AKA VITAMIN D3
Many popular rat poisons like d-CON, Ortho Mouse Be Gone, Rampage and Quintox include the active ingredient Cholecalciferol or Vitamin D3. The poison bait comes in a variety of forms, such as granules, pellets and blocks. Cholecalciferol has become a popular choice over traditional anticoagulant rodenticides, which have gone under stricter EPA regulations. Additionally, some rodent populations have become resistant to traditional anticoagulant bait, further driving the use of cholecalciferol.
Why vitamin D is deadly to pets
Cholecalciferol or vitamin D kills by causing an excessive increase in calcium and phosphorus levels in the blood, hardening soft tissues throughout the body, particularly in the heart, kidneys, gastrointestinal tract, and muscles. This damage can lead to acute kidney failure, and multiple organ failure, and death.
Time is of the essence if your dog or cat ingests rodent bait that contains cholecalciferol. There is no antidote for your pet, making this one of the most dangerous and lethal poisons to manage. Treatment includes reducing the calcium level of the blood as quickly as possible before tissue calcification and organ failure occur.
Vitamin D is not only toxic to your pets in rodenticides, but also in human supplement form (multi/prenatal vitamins, drops, gummies), topical psoriasis creams, and prescriptions for osteoporosis.
Signs of vitamin D poisoning in pets
Once ingested, your pet may show signs of poisoning within 12-48 hours. Act fast and get to an emergency vet if you notice any or all of the signs below:
Decreased appetite
Drooling
Increased urination
Increased thirst
Weakness
ANTICOAGULANTS
An anticoagulant disrupts blood clotting and leads to internal bleeding. Without treatment, ingesting it can quickly be fatal.
Anticoagulants have been an active ingredient in traditional rodenticides for many years. As such, some rats have become resistant to them, particularly First Generation Anticoagulant Rodenticides (FGARs) which include warfarin, chlorophacinone, and diphacinone. These take multiple exposures to kill rodents.
Second Generation Anticoagulant Rodenticides (SGARs) such as brodifacoum, bromadiolone, difenacoum, and difethialone, are much more toxic, and are typically restricted for use by professionals only. Not only are these SGARs fatal to rodents after a single ingestion, they pose a lethal threat to non-target species, such as owls, birds of prey and pets who ingest the poisoned rodents, and to scavengers who eat the carcasses of the animals who ate the poisoned rodents. Ratsak, Contrac Blox, JT Eaton and Ditrac Blox are popular rodenticides that include anticoagulants as their active ingredient. While commonly sold as hard bait blocks, pellets and soft bait, they are also available in liquid, powder and granule formulations.
How anticoagulants disrupt blood clotting
Anticoagulants inhibit the normal production and recycling of vitamin K, which is essential for the liver to produce blood clotting factors. When the blood cannot clot, internal bleeding occurs and death follows, usually after several days. It is imperative to get your pet to the vet immediately if you suspect he or she may have eaten rodenticide or a rat or mouse who may have been poisoned. Treatment includes administering activated charcoal and vitamin K1 supplementation. Later stage treatments may require blood transfusions.
Symptoms of anticoagulant poisoning
It may take a few days for your dog or cat to show signs of poisoning. Some symptoms to keep an eye out for are:
Bleeding from mouth or nose
Bloating/swelling
Breathing problems
Coughing
Increased heart rate
No interest in food
Weakness
BROMETHALIN
Commonly found in the Tomcat brand, and distributed in the form of bars, blocks, and pellets, bromethalin is a fast-acting neurotoxin used in rodenticides, affecting the nervous system. Bromethalin can cause neurological disturbances, as it makes it impossible for the brain to maintain aerobic metabolism, causing brain swelling and death.
How bromethalin causes neurological damage in pets
There is no antidote for bromethalin poisoning, so here again, getting your pet to the vet immediately - within an hour of ingestion - is essential for its survival. There are two forms of bromethalin poisoning recognized in pets:
Convulsant form - Occurs when larger amounts of bromethalin have been ingested. Symptoms can occur within hours of eating the poison, and the prognosis for survival is often poor.
Paralytic form - When smaller amounts of bromethalin have been consumed, symptoms may not occur for several days. Treatment is possible, but must be aggressive.
Treatment includes activated charcoal administration, sedatives or muscle relaxants for muscle contractions, diuretics for brain swelling and anticonvulsants for seizures. It can take several weeks to determine if permanent neurological damage has occurred.
Signs of bromethalin poisoning
Symptoms of bromethalin in dogs and cats, and other pets vary from mild to severe. Here are some signs:
Lethargy
Loss of muscle tone
Paralysis
Tremors/seizures
Wobbling
WHAT ARE THE SIGNS OF RAT POISONING IN DOGS AND CATS?
The active ingredient of the rodenticide ingested, the amount, the length of time from when the poison was eaten and the size, age and overall health of your pet can all impact the signs of rat poisoning in your dog or cat.
It’s worth repeating that getting your pet to the vet immediately if you suspect he or she has eaten rat poison is essential, since signs of toxicity can take from 1-7 days to appear, negatively impacting treatment success.
Any time your pet shows signs of lethargy or weakness, lack of coordination, paralysis, tremors, seizures or collapse, rat poison toxicity should be considered a possible cause.
Here’s a quick recap of symptoms based on rodenticide type:
Cholecalciferol/Vitamin D3
Hardening of the soft tissues due to increased calcium causes organ failure, with the kidneys being the most susceptible.
Increased thirst and increased urination (possible signs of kidney failure)
Weakness
Not eating/vomiting
Drooling
Anticoagulants
Inhibition of blood clotting factors causing internal bleeding and anemia.
Lethargy
Pale gums
Increased heart rate
Breathing problems/coughing
Weakness/collapse
No interest in food
Bloating/swelling
Bleeding from mouth or nose
Bromethalin
This neurotoxin affects the central nervous system causing the brain to swell.
Lack of coordination/stumbling
Lethargy
Tremors/seizures
Paralysis
SAFEGUARDING YOUR DOG OR CAT FROM RAT POISON
Help keep your pet safe from rat poison by following a few steps:
Assess your surroundings
Rats and mice live in groups, so if you see one, there are more around.
If you see bait traps, keep an eye out for dead or sick rodents that may have ingested poison. Keep pets on leash and away from traps or dead animals.
If you have a fenced yard, check for evidence of rodents (droppings/chewed areas), especially if you have bird feeders, a shed where you keep seed or straw, or areas of tall grass.
If you’re leaving your pet with a sitter or neighbor, ask if they have bait traps or rodenticides in use.
Keep an eye on your pet
Both rats and mice are nocturnal, so keep pets leashed in the evenings. Check your yard for rodents and turn on outdoor lights before letting pets out.
Many rodenticides contain bright dyes that can appear in your pet’s stool. If you see any kind of foreign material in your dog’s stool, save it and bring it with you to your vet ASAP.
Additional steps to take if you have a rodent problem and you have pets:
Keep all trash secured in tightly closed bins
Don’t use bird feeders
Keep grass seed in tightly closed bins in shed or garage
Check your home’s perimeter for any openings or gaps and seal or cover them
Keep gardens clear of weeds, keep shrubs trimmed and branches off the ground
Try non-toxic repellants like Messinas Rodent Stoppers
Use pet-safe live traps
Carefully read all directions for any rodent killer or deterrent you’re using
Opt for pet-safer products like RatX that use corn gluten meal and sodium chloride specifically to dehydrate rats and mice
Ensure rat bait (even “safe bait) is inaccessible to your pets
Note the ingredients (brand name and active ingredient) in any bait you use so you can convey this to your vet in case of emergency
CONTACT YOUR LOCAL VEG FOR ALL PET EMERGENCIES
The ASPCA lists rodenticides as a top cause of pet poisonings each fall. Even a small nibble can be fatal. VEG ER for Pets sees these cases spike during autumn.
