As the weather gets colder, rats and mice are seeking shelter. They enter your home and nest in your garage, attics and even in the walls. In a haste to get rid of them, you go to the nearest store and purchase rat poison (rodenticides). You put out the rat bait strategically where the rats may eat it and die. A few weeks go by and you notice that your dog or cat is eating something. You try to take it out of his mouth, but he swallows it. As you wonder what he just ate, a frightening thought just comes to your mind. Could he have eaten the rat bait I put out? You go back to the places where you’ve placed the rat poison and you see that it is gone. Thoughts are running through your head – maybe the rats ate it. But what if my dog ate it? You call your veterinarian and she tells you to bring Fluffy in right away.

If you suspect that your pet has ingested rodenticides, the first step is to find the original rat bait packaging or know the accurate name. Please do not guess, because your pet’s life may be at stake. Simply naming the shape, color and size of the bait will not be helpful. The ingredients in brands are vastly different and their mechanism of how they kill the rats are dramatically different. Your veterinarian can provide effective treatment only if you provide accurate information on the active ingredients and EPA registration number.

Below are four of the most common types of rodenticides on the market, mechanism of kill, symptoms, and treatment.

1. Anticoagulants (prevents blood from clotting)

Mechanism of kill: This rodenticide works by stopping blood from clotting which causes internal bleeding. If your pet ingests an anticoagulant rodenticide, it takes about 48 hours for the anticoagulant to take effect.

Symptoms: Your pet may become weak, pale, have difficulty breathing, coughing, lethargic, vomiting, diarrhea, bruising, blood in urine, nose bleeds or may bleed from the gums.

Treatment: Your veterinarian will treat with vitamin K1 for 4 weeks and at that time do a blood test to make sure the anticoagulant has been sufficiently blocked. Please do not attempt to treat yourself with OTC vitamin K containing supplements.

2. Cholecalciferol (vitamin D3)

Mechanism of kill: This rodenticide causes the calcium and phosphorous to become so high in the body that it causes kidney failure.

Symptoms: Increased drinking and urination, weakness, decreased appetite and lethargy about 24 hours after ingesting the poison. Onset of kidney failure is seen within 2-4 days.

Treatment: Specific antidote for this rodenticide is absent, but it can be treated with aggressive hospital treatment and extensive monitoring. Because of the intense treatment, a long hospital stay is needed which can be quite costly. Even a small amount of ingestion is toxic and can be fatal so contact your veterinarian as soon as possible.

3. Bromethalin

Mechanism of kill: This rodenticide causes swelling of the brain (cerebral edema).

Symptoms: Your pet may lose coordination, have tremors or seizures, become paralyzed and eventually die. After ingestion, you can see these signs within 2-24 hours after ingestion depending on the amount your pet ingests.

Treatment: Intense hospitalization and therapy is needed to reduce swelling of the brain. Your pet may need to stay hospitalized up to 6 days.

4. Zinc, calcium, aluminum phosphides

Method of kill: This rodenticide releases poisonous phosphine gas in the stomach.

Symptoms: Vomiting, bloating, intense stomach pain, collapse and shock.

Treatment: There is no specific antidote. Your veterinarian may lavage the stomach (pump the stomach) to remove as much of the poison and gas as possible. Because noxious gas is formed in the stomach, do not try to induce vomiting at home. Special care must be taken when inducing vomiting to prevent human exposure to these gases.

Wow! All of these sound horrible. So the next time you are considering putting out rat bait, choose a smarter alternative. Purchase a rat trap instead. There are many great rat traps on the market that are poison free and easy to use. If you have already put rodenticides out, please remove all of them and replace with traps. Importantly, find out if your neighbors have put out rodenticides. Even though your pet may not be able to get into their home to eat the rat baits, your pet may eat the dead rats that have ingested the rat poison from neighbors.

If you believe that your pet has ingested rat poison, immediately call your veterinarian.