Top 10 Deadly House and Garden Poisons for Your Dog and Cat

Did you know that there are a lot of powders, liquids and other substances around the house and garden that can easily kill your cat or dog?  Our pets will frequently come across these poisons unless special care is taken.  In most cases it is far better for you to use an alternative than risk an emergency trip to your vet.  


The two most common pet poisoning scenarios are a cat or dog eating human food that is toxic to pets or coming across something around the house or garden that they shouldn't have had access to and becoming seriously unwell.  Check out my other article if you're wondering what the most common poisonous foods for dogs and cats are.

10 deadly poisons in the house

  • Rat Bait

  • Slug Bait

  • Antifreeze

  • Lilies

  • Glow sticks

  • Household cleaners

  • Permethrin

  • Paracetamol

  • Aspirin + ibuprophen

  • Other human + pet drugs

Let's start off outside before moving indoors

1 - Rat Bait

At number one is rat bait.  There are several different types with the most common being a warfarin or warfarin-like poison.  Rat bait is designed to be tasty, after all that is why rats and mice eat it.  This means that if your pet can smell it they are likely to try and get to it to eat.  Strong packaging is no match for a determined dog and hiding it somewhere pet inaccessible is ineffective too as it can be moved by rodents.  If you have pets, never use rat bait.  Simple.

These poisons work by preventing the blood from being able to clot, causing our dogs and cats to bleed to death.  This might be bleeding into the lungs and drowning, bleeding into their intestines or abdomen, bleeding into their joints or even bleeding under their skin.  If they eat enough, and this amount varies a lot depending on the exact product they eat, then without treatment they will die.  Thankfully there is a very effective antidote but even this needs to be given early enough and for many weeks before your pet can be considered fully recovered.  The reason for this is that the poisons stays in the body for many weeks.

There are other forms of rat bait that use a high dose of vitamin D3 also known as cholecalciferol.  This causes blood levels of calcium and phosphorus to become really high.  This damages many parts of the body with the kidneys being especially vulnerable.

Unfortunately by the time a cat or dog is showing signs of poisoning the damage to the kidneys is often so severe and permanent that even aggressive treatment may not be enough to save their life.  There is no specific antidote so if you have any suspicion your pet may have eaten this type of rat poison, or if they get into your vitamin D supplements, it is essential they are seen by their vet straight away.

2 - Slug Bait

At number 2 is another poison used to kill a common pest.  Slug bait, or metaldehyde, is very toxic to our pets and unfortunately it is also pretty tasty.  This means it is not unusual for them to seek it out and eat large quantities.  To make matters worse, because slug bait is so toxic it would only take a tiny 18 g of a stronger 5% formula to be potentially deadly for a 20 pound (9 kg) dog.

Once eaten, metaldehyde slug poison is very quickly absorbed and problems start about 1 - 3 hours later.  It causes a patient to "shake and bake".  They develop tremors which progress to full seizure and the body temperature starts to climb to dangerous levels.  This high temperature is then responsible for secondary organ failure and death without rapid, aggressive treatment.

I said this with rat bait, if you have pets then do not use slug bait.  It is deadly.

If you have pets, never use rat bait. Simple, they are deadly poisons

3 - Antifreeze

Its a hard choice to make but I would rate antifreeze or ethylene glycol, as the worst poison on this list.  Not only does it only take as little as a teaspoon to kill a cat and a tablespoon to poison a small dog, the initial signs seem to improve leading to a false sense of security.  Despite this "improvement" it is vital that treatment is started within the first couple of hours or this poison is pretty much 100% fatal.

To start with, often within 30 minutes, a cat or dog may seem as though they have drunk too much alcohol with in-coordination, vomiting, drooling and urinating more.  Between 12 - 24 hours they will seem to get better and may even become "normal" but inside, their kidneys will be shutting down.  This will show itself as inappetence, lethargy, depression, vomiting, seizures, coma and by the time this stage is reached death is inevitable.  Even if aggressive treatment is started early the chance of success is very slim.

When you are changing or topping up the fluids in your car it is so important you don't spill any.  A cat who walks through a small puddle of spillage would have enough soaked into their fur that they will be poisoned when they groom themselves.  Antifreeze also tastes sweet and so dogs may readily lick up a puddle.

4 - Lillies

Lilies might be found in the garden or in the house depending on where you live but regardless, they can be deadly for cats.  To start with, this only applies to the true lily species of the Lillium or Hemerocalis species.  Lily of the Valley can also be deadly to both dogs and cats but we'll consider that in a minute.

The true lily contains a poison in it's leaves, pollen and stem that causes a cats kidneys to fail.  A cat can be poisoned by eating the plant or poisoning can also take place if its coat gets contaminated with pollen (such as from brushing up against a fresh bunch) which it then eats when grooming.  As with all the poisons so far, rapid, aggressive treatment is important if we are to give them the best chance of making a successful recovery.

Dogs are not affected by the true Lily but both dogs and cats can be poisoned by Lily of the Valley.  This plant is similar to the Foxglove and so affects the heart rather than the kidneys.  It can cause a low heart rate, an abnormal rhythm, possible seizures and can also be fatal.

5 - Glow sticks + jewelry

Continuing indoors, at number 5 is a surprisingly common but thankfully pretty harmless toxin.  Glow sticks and jewelry contain a chemical called dibutyl phthalate which is an intense irritant.  It is very bitter and causes some pretty severe looking symptoms including profuse drooling, gagging and retching.  Because it is irritant the mouth and eyes may sting and so your cat or dog may become quite distressed, paw at their mouth and rub their eyes.

Thankfully, while your pet may become quite agitated and the signs they show may appear alarming, the actual chemical is not very toxic and so they should recover fairly uneventfully.

6 - Household cleaners

The next poisons in the house are household cleaners.  This includes many different types but the result can all be the same.  Household cleaners are often strong acids or alkalies that are not only irritant but can also be corrosive.

Acids are generally bitter and result in fairly immediate pain when they come into contact with the gums or tongue.  This means that ingesting large amounts is uncommon but there is still the potential for significant injury to the eyes, skin, mouth, intestines and airways.

Alkalies cause similar problems but they are potentially much more dangerous.  This is because they are generally tasteless and odorless meaning that larger volumes are often consumed.  This increases the risk of severe intestinal ulceration with the potential for perforation or rupture which is likely to be fatal.

As ever, prompt treatment is essential and this can be started at home by flushing the affected area with copious amounts of water before seeking immediate veterinary treatment.

7 - Permethrin

This one is just really a cat problem. Pyrethrins and pyrethroids (of which permethrin is perhaps the most common) are found in some dog flea and tick preventative medications.  While a massive overdose would be harmful to dogs, cats are exceptionally sensitive to these chemicals due to their inability to break them down within the body.  If these treatments are inappropriately applied to a cat then they will quickly show signs of toxicity.

This most commonly results in nervous signs such as tremors, twitching, in-coordination, weakness and seizures.  Vomiting, excitability, drooling and breathing difficulty can also be seen.  Left untreated poisoning can be fatal.

If the product is accidentally applied then it should be washed off straight away with soap (a washing up liquid or dish soap is good for this).  It is important that the area is fully saturated and rinsed many times as cats long hair coat can make complete removal of any substance challenging.  

It is much less common for cats to be poisoned by coming into contact with a dog who has just been treated.  Prevention is the safest plan though, so if you have both cats and dogs then I would advise you to either avoid using these products on your dog or at least keeping them confined for several hours while the product dries.

If your pet is showing signs of toxicity despite having washed them thoroughly or they become unwell soon after you have treated your dog then you should take them to your local vet clinic for treatment to ensure a successful recovery.

8 - Paracetamol / Acetaminophen

Never give your cat paracetamol.  Not even a little bit.  Cats are unable to break down acetaminophen in the same way as people (and dogs).  Instead the liver breaks it down into a toxic chemical.  This results in severe liver damage and also prevents the red blood cells from carrying oxygen and delivering it around the body.

After consuming paracetamol you might notice that your cats gums turn blue or look like chocolate.  Their breathing will become rapid and they will start to struggle to breath.  They will become depressed and their face and feet may also start to swell in size.  As the body continues to struggle, vomiting will start and the urine will turn a dark brown.  Unfortunately by the time a cat is showing severe signs of poisoning the chance of recovery is minimal, it is pretty much always fatal.  Even with prompt treatment, this poisoning is generally fatal.

While cats are uniquely sensitive to paracetamol, dogs are not and are generally able to take acetaminophen without developing any problems.  That said, it should only be given as advised by your veterinarian.  Dogs are not small people and an overdose can severely damage their liver.  Given appropriately though it is safe.

list and pictures of the most common house + garden poisons for dogs and cats

9 - Aspirin and Ibuprofen

Aspirin (acetylsalicylic acid) and Ibuprofen are our other most common drug toxicity.  Again most often a result of being given to our pets inappropriately by well-meaning owners.  Just like paracetamol however, our dogs and cats may decide to chew on a packet left lying around and so be poisoned this way.

Both aspirin and ibuprofen are examples of non steroidal anti-inflammatory drugs (NSAIDs).  While NSAIDs are used to control pain in our pet population, only specific veterinary drugs should be given.  Human types are not safe for either dogs or cats and it is all too easy to result in severe, life-threatening toxicity.

Intestinal signs of poisoning are most often seen such as vomiting and diarrhea.  Vomit may contain fresh blood or the stools might be very dark and tar-like due to ulceration and bleeding within the stomach or guts.  Any ulcers can also perforate causing a fatal peritonitis.  As if this weren't bad enough, overdose can also lead to liver failure, kidney failure and seizures.

Aspirin is occasionally used to treat certain conditions but when used in this way, tiny doses are given and close monitoring takes place.  Unless specifically told to do so by your vet, never give your cat or dog or ibuprofen (or any other NSAID you may have at home).

10 - Other Human and Veterinary Medicines

Last but not least, at number 10 on our top 10 deadly poisons around the house and garden for dogs and cats is any other medication you have in the home, human or animal.  The most common reported ones are heart medication, antidepressants, ADHD treatments, cold and allergy medications and sleeping pills.

It is also not unheard of for pets to seek out whatever medication they themselves are on as many are designed to be palatable.  For those dogs or cats which really do view their medicine as a treat, there is a very real potential for them to chew up the container and consume a whole months worth of treatment given half a chance.

Signs of poisoning really depend on what drug your pet has eaten.  By now though you should be aware of the most common symptoms of toxicity which can include vomiting, diarrhea, drooling, weakness, depression, being off their food, a change in their gum color, rapid breathing, tremors, twitching and seizures.

In some cases, a single tablet of certain human medications can be enough to result in toxicity.  This means that not only should you keep any medication safely locked away, when you are getting any out of the container it is best if your pet is not in the same room so that should any be dropped they can be found before your pet has a chance to eat them.


I hope this article helps to prevent your cat or dog from being poisoned.  Make sure you also check out the top 10 deadly food for dogs and cats.  If you have any questions or anything you would like to see in future articles then please leave a comment below.  I would love to hear from you.  Also be sure to sign up to my newsletter to make sure you don't miss out on future content and get your free copy of my weight and diet calculator.

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