The Use of Domestic Poisons – Rat poisoning in pets and control of rats and mice

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How do Domestic Poisons affect your pets?

Rat poisoning in pets

Treating pets poisoned by rat poison

Most people assume that poisons used in the home, either to control pests such as rodents, ants or snails, or insecticides sprayed on plants will not affect pets or that pets will not consume poisons intended for use in other species. People sometimes inadvertently poison their pets themselves at home while trying to treat them for parasites or illness. In this health focus, I am going to list the basic and most common household poisonings seen in domestic animals, and also how we treat pets for these poisonings, if there are antidotes available and how we can prevent our pets getting poisoned by mistake. I will focus on one main poison a week over the next few weeks.


How rat poisons affect pets

Rat poisons can kill your beloved pets

This is by far the most common accidental poisoning I see in dogs. I have also seen cats also poisoned with rodenticides, but only in cases where they were being maliciously poisoned by lacing meat with the poison. Dogs, however, like the taste of these poisons and will happy eat an entire box if they can. Common mistakes people make when putting these poisons out:

  • Putting them on the roof. True – dogs cannot get to them there – until it rains and they are washed down.
  • Hiding them behind appliances in the kitchen. They are forgotten there until spring cleaning when appliances are moved, to clean behind them or to repair them, often by people who had no knowledge of the poison being there in the first place
  • Putting them in an area where the dog can easily get to them but the dog does not usually frequent. Dogs go everywhere they can get to. They just need to go there once.
  • Hiring an external company to exterminate vermin on your property. These people may have no pets of their own and often scatter the poison indiscriminately round the garden and house while you are at work and by the time you are home, your pets have eaten the poison.


1. Warfarin and Coumarin based poisons

These come in long and short acting forms. These poisons stop the blood clotting inside the body, leading to internal hemorrhage and death.  They are known as vitamin K antagonists. Vitamin K is made by bacteria in the gut and is needed by the liver to make clotting factors – chemicals that make the blood stick together or clot. By blocking vitamin K, the liver cannot make clotting factors,  and when the existing clotting factors in the blood have been used up, the slightest bump can start internal bleeding.

A long acting anticoagulant poison

Pets eating longer acting poisons may need blood transfusions to survive

These poisons come either as pellets, often brightly colored in pink or blue or in slabs that resemble chocolate, usually also brightly colored. If dogs find these poisons scattered round the garden or hidden behind something in the kitchen, they WILL eat them. Dogs and cats usually will not get ill if they eat a  single rat that was poisoned, but if you have an infestation, smaller pets consuming a few rats or mice a day run the risk of being poisoned.

Symptoms of poisoning:

  • Symptoms only start after a few days when the clotting factors run out, and depend on how much poison was taken in and whether it is a short of long acting poison. Long acting poisons stay in the body for weeks.
  • Pale gums and tongue
  • Heavy or difficult breathing
  • Depression
  • Black stool
  • Weakness
  • Pounding heart
  • Vomiting
  • Blood in urine
  • Sudden death

symptoms of rat poison

Pets may die as suddenly as these rats


Vitamin K by intravenous injection, until stabilized and then followed by a course of vitamin K tablets, possibly for up to two weeks after being diagnosed as being poisoned.All animals suspected of taking in rat poisons are treated routinely with this antidote, even if they vomited the poison out.


If the dog or cat has consumed the poison in the last hour, your vet will try to make your pet vomit the poison out. This is the best thing to do before the poison can do any damage.  Your vet will use drugs like Apo-Morphine to make your pet vomit, or a sedative that makes them vomit routinely such as Xylazine.  If you are unable to get to an emergency vet and you want to make your pet vomit, the best thing to use is ordinary plain washing powder, mixed with a little water to make it stick together and then forced down the throat. Be careful – don’t induce vomiting with all poisons, as some poisons cause seizures and your pet will inhale the vomit if he seizures at the same time. Rather speak to an emergency vet on the phone to make sure it if safe to induce vomiting at home before doing so.

If your dog or cat consumed the poison a few days ago and is showing symptoms of internal bleeding, then he may need a full blood transfusion to save his life. This will be followed by a drip and a few days on intravenous vitamin K to stabilize him. Your vet may also use activated charcoal tablets to absorb some of the poison out of the body.

2. Vitamin D based rodenticides (cholecalciferol, calciferol)(Quintox, Rampage, Ortho Mouse-B-Gone, Ortho Rat-B-Gone)

Vitamin D based rodenticides are lethal, but luckily not as common as Warfarin based rodenticides.  These poisons make the body absorb calcium in huge quantities. This calcium is absorbed into the bloodstream and carried round the body, where it is deposited in soft tissues such as the lungs and kidneys. In the kidneys, this leads to kidney failure as the kidneys harden and gradually lose the ability to work.

Vitamin D based rat poisons

Vitamin D based rat poisons cause kidney failure

Symptoms of Poisoning:

  • Excessive thirst
  • Dilute urine initially
  • Dog or cat urinates frequently
  • Anorexia
  • Shivering and Twitching
  • Vomiting
  • Later on urine production may even slow down or stop
  • Depression
  • Weakness
  • Seizures
  • Death


There is no antidote


If they have just consumed the poison, getting them to vomit it out is the best thing, then they are put on intravenous drips to flush the kidneys through and also given diuretics to flush the kidneys through. Activated charcoal tablets are dosed orally to help absorb the poison.  The prognosis is guarded if caught early and poor if caught when the animal already has kidney failure.

3. Some rat poisons combine both of the above types of poison and thus will need both types of treatment.

4. Phosphides

These contain zinc phosphide which reacts in the rat’s stomach to make phosphine gas which kills the rats. People who own pets can use this type as pets cannot pick up the poison from eating a dead rat or mouse.


No antidote exists


Try to induce vomiting

5. Bromethalin (Assault, Vengeance)

This causes cell swelling in the nervous system of the rat and respiratory paralysis with tremors, hyperexcitablity, seizures and and death a few hours after it is eating. It is a very effective poison.Symptoms occur about 10 hours after it is eaten.




Very poor.


I personally feel that these poisons are not humane and, although I see the necessity for them in some cases, there is a lot people can do to get rid of rats or mice in the home that would allow minimal use of these horrible poisons.

Alternatives to rat poison

Alternatives to rat poison

  • Cut away all trees, creepers and shrubs in the garden that are tall enough to reach the roof. Rats and mice use these to go up and down the house into the roof. I have found that even cutting trees away when rats are already in the ceiling helps.
  • Do not leave seed, pellets or feed in accessible bags that can easily be chewed open. Use thick, seal-able plastic containers that shut tightly.
  • Natural pest control.  Get a terrier dog or a few cats. These pets will hunt rats and mice and keep the population numbers down. Note: if you feed your pets so much that they become obese and sleep all day, this won’t work! Pets should stay slim and trim to hunt. Remember, if your pets hunt rats and mice to worm them every three months as they can pick up tapeworms this way.
  • Use humane rodent traps and release them far away from your home, in an open, unpopulated area. Tipping them over the fence will not stop them coming back.
  • Electronic rodent deterrents emit a noise that affects the nervous system of rodents, making them unable to communicate, and this keeps them away from certain areas. They can affect domestic pets like tarantulas, gerbils, guinea pigs, hamsters and pet rats and mice. One unit plugged in per room is recommended and they take a few weeks to be effective. They are also effective against some smaller vermin such as cockroaches.
  • If you have to use poison, use it in the ceiling only, where no pet can get to it, ever.

animals that kill rats

Terriers are excellent ratters

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