11 Poisonous Foods That Can Kill Your Dog and Cat

Did you know that a lot of foods that we love to eat are actually poisonous foods for cats and dogs?  They may even be deadly.  So what snacks should you never feed your dog and which foods are best locked away from your cat?  Stick around to learn about the top ten deadly foods for our pets.

 
 

We often love to share our food with our pets but stop and think again.  Is this actually safe and which food should we avoid giving our cats and dogs.  If your pet eats any of these things then the best thing to do is to get advice straight away from your local vet.  Don't wait until they are developing problems because by then it could be too late.  It will certainly be much more expensive.  Better still, avoid giving them to your pet in the first place.  Don't leave them lying around and make sure they are stored away safely in cupboards.  Preferably ones your pet can't open!

1 - Chocolate

At number one is probably the most common poisoning seen at the vet clinic (but thankfully not the most dangerous), chocolate.  It is irresistible to us and also to our pets who will often break into a cupboard or climb a shelf before consuming a whole box of chocolates, often packaging and all!  Now what happens next really depending on the size of your pet and the type of chocolate involved.  Its fairly obvious that the larger the dog the more they have to eat to get sick but did you know chocolate type also plays a huge role?  This is because different types contain different amounts of the poisonous ingredient theobromide.  Generally the posher or more expensive the chocolate the worse the problem and chocolate for cooking is even worse.

White chocolate contains tiny levels, milk chocolate contains more with dark chocolate, cooking chocolate and cocoa powder containing very large amounts of theobromine in comparison.  So clearly the danger is worse for our smaller dogs.  A 5 kg (11 pound) dog would only need to eat around 15 grams, or half an ounce, of dark chocolate to start suffering from signs of toxicity.  This is not very much!  If it was milk chocolate though, they are only likely to start having problems after eating 60 grams or over 2 ounces.  A 30 kg or 66 pound Labrador however would need to eat 360 grams  (12 ounces) of milk chocolate or 90 grams (a little over 3 ounces) of dark chocolate before showing signs of poisoning.

Chocolate toxicity causes problems ranging from from vomiting and diarrhea, through to heart arrhythmia's, bloating, tremor, seizure and death.  Thankfully most dog owners are very aware of the dangers of chocolate and severe, untreated poisoning is rare.  In most cases a quick trip to the vet to make them sick is all that is required but if they ate the chocolate more than a few hours previously or they ate a very large amount above the toxic dose then they may need hospitalisation for closer monitoring and treatment.

Cats are also affected but as they are unable to taste sweet things they don't tend to be too fussed by chocolate and so generally leave it well alone!

2 - Grapes and Raisins

At number two (in no particular order) on our list of poisonous foods is grapes and raisins.  This is less clear cut than chocolate for several reasons.  The first is that no-one knows exactly what it is in the grape that causes the problem, and the second is that not every animal is affected equally.  Some can gorge on grapes and be completely fine.  What we do know is that eating grapes or raisins can cause irreversible kidney damage resulting in death.  We also know that there have been reports of some dogs eating only a small handful of grapes showing signs of poisoning.

The lowest reported toxic dose for raisins is 0.04 oz per pound or 2.8 g per kg, and for grapes the lowest reported toxic dose is 0.32 oz per pound or 19.6 g per kg body weight. This means that a 10 pound, or 4.5 kg, dog can be poisoned by as little as 17 grapes or 11 raisins.  A 40 pound (18 kg) dog would therefore need to eat 68 grapes or 44 raisins.  Having said all that, there a reports of an 18 lb (8.2 kg) dog dying after eating only 4-5 grapes.  The bottom line is that we don't know how many grapes or raisins will kill a dog, for some it may be a very small number while others may eat a much larger amount and be completely fine.  Cats again can also be affected but as with chocolate they tend to be more selective as to what they eat.


We don't know how many grapes or raisins will kill a dog


This presents a problem.  What should we do if we know our pet has eaten grapes?  Some people will be happy to just watch their pet and if they show any signs of problems such as vomiting, diarrhea, pain, weakness, wobbliness or if they go off their food to then seek treatment.  The problem with this approach is that if the kidneys are damaged then this may be irreversible and treatment may not be able to save them where more may have been able to have been done had they seen a vet straight away.  

Because the consequences are so severe I would recommend a more risk averse approach.  If your pet has eaten more than the lowest reported toxic dose then you should contact your vet straight away for advice.  If they have eaten any grapes or raisins then there is an argument that you should still contact your vet straight away.  Prompt treatment is much more likely to be successful compared to treatment after your pet is already unwell.

3 - Onions, garlic, leeks + chives

This one might surprise you but onions have the potential to be very poisonous in our dogs and cats.  They lack the enzyme to properly digest them which can lead to destruction of the bodies red blood cells.  In extreme cases this resulting anemia may cause death.  Other members of the Allium family include garlic, chives and leeks; all of which can cause the same problem.

Thankfully it takes a lot to be eaten in a single sitting to cause such severe problems, a 30 pound (14 kg) dog would need to eat 2 pounds (900 g) of onion in a single sitting.  That's about 8 medium sized onions, although 6 onions would still be enough to make them very unwell.  Cats however are much more sensitive with a standard 9 pound (4 kg) kitty only needing to eat 15 - 20 grams of onion for poisoning to occur.  Garlic is 5 times more potent, although a single serving of pizza or mince with a sprinkle of garlic powder is unlikely to cause problems.  Again a relatively large amount would need to be eaten in a single sitting and the risk is relatively low.

You might think then than this means there is no cause for concern.  Unfortunately these foods don't need to be eaten in one go.  Repeatedly eating smaller amounts can cause exactly the same problem.  Think about this for a minute if you are a garlic lover and regularly give your pet left-overs.  Something else to consider is those of you giving your pet a garlic based flea or worm remedy.  Not only do they not work, they may be seriously harming your pet, especially if they then get hold of a relatively small amount of additional onion or leek.  To make matters worse, some medications can also make an animal more susceptible to the effects of onion, garlic and leek.

Signs of toxicity generally take several days to occur and may include depression, bloody urine, pale or yellow gums, rapid breathing, weakness, lethargy, abdominal pain, vomiting and diarrhea.  By the time you see these then your pet has already had a significant number of their red blood cells destroyed and intensive treatment will be needed.  If treatment is not given then death is a very real risk.

block of dark chocolate
onion and garlic bulbs
bunch of green grapes

4 - Xylitol

You may not have even heard of xylitol but it is used as a sugar-free sweetener.  It is found in a large range of products, not just sugar-free gum, and seems to be becoming more common.  Xylitol can be found in anything from sugar free baking, ice creams and yogurts, sugar free sweets, gum and chocolate, some peanut butters, honeys, artificial sweeteners, various sugar free condiments and sauces as well as protein bars and powders.  That's a lot of foods that have the potential to be dangerous.

To make matters worse, xylitol is also found in some skin care creams and cosmetics, in toothpastes and mouthwash, in human medications and supplements and it may even be present in some active wear clothing.  Xylitol may not even be on the ingredients list.  It may instead say "sugar alcohol", of which xylitol is one possibility.  Anything labeled "sugar-free", "natural sweeteners" or "no added sugars" should have the ingredients double checked.

 
 

So what does it do?  Well first up, it is dogs who are much more sensitive to it than cats, although there have been some reports of cats being affected too.  Xylitol poisons our dogs by very rapidly dropping their blood sugar levels, often within 30 - 90 minutes of ingestion although it can take up to about 18 hours depending on what exactly was eaten.  Its effects then last for around 24 hours or longer.  Xylitol can also cause irreversible liver damage if an animal lives for long enough, as a very low blood sugar level can lead to coma and death.  Initial signs of toxicity include weakness, lethargy, in-coordination, vomiting, an increased breathing rate, seizures, collapse, coma and death.  If liver failure occurs later then jaundice, vomiting, diarrhea and inappetence are just some things that may be seen.

So how much needs to be eaten? Not a lot, this is one of the most toxic substances on the list.  A 60 pound (27 kg) Retriever would only need to eat a tiny 2-3 grams to cause a drop in blood sugar levels and 10 to 15 grams to cause liver failure!  That's not much when you might have a 500 g bag in the cupboard or use 2 cups to make a cake.  There may be up to 1.5 g in a single piece of gum (enough to poison a 20 kg dog) and 22 grams of xylitol containing peanut butter may be more than enough to poison a 10 lb (4.5 kg) dog.

The risk is very real.  If there is any chance your dog has eaten something containing xylitol take them straight to your vet.  Because it works so quickly, any delay could be deadly.

 
top 10 deadly and poisonous foods for cats and dogs list
 

5 - Macadamia Nuts

Macadamia nuts make every poisonous food list.  In reality they are not nearly as bad as the other food items discussed here.  Like grapes, the mechanism of toxicity is not understood but when a sufficient quantity is eaten (about 2.4g per kg body weight) then a non-fatal syndrome characterised by vomiting, in-coordination, weakness, raised body temperature and depression can result.  Severely affected dogs may need supportive care to prevent other problems from  developing, and so aid recovery, but even when dogs were given over 8 times this toxic dose they all recovered within 48 hours with supportive care, after taking up to 12 hours to show signs of toxicity.

6 - Bread dough

If you are a home baker then this one is for you.  Bread dough left to prove is a tempting snack for your dog or cat.  If eaten, the warm stomach is an ideal environment for the yeast to get to work making the dough rapidly increase in size.  This stretches the stomach which can disrupt its blood supply, cause it to twist or even result in significant breathing difficulty.  To make matters worse the yeast will also start to produce ethanol, or alcohol, which causes even more problems such as depression, weakness, disorientation, low body temperature and yes, even death.  In fact it is alcohol toxicity that generally causes death in bread dough poisoning.

Of course this can all be treated but far better to avoid the problem in the first place

7 - Moldy Food

You might think that our pets should be able to eat most things that have gone off a little bit but there are real risks to them if they get hold of the rubbish bin or composting waste.  One of these is poisoning due to mold.  Molds actually produce a toxin that can start acting within only a couple of hours of being eaten and cause nervous impairment.  Common initial signs including wobbliness, in-coordination, muscle tremors, a high temperature, vomiting and excessive salivation.  This can progress to full seizures and fitting and you guessed it this can then lead to death.

With appropriate treatment thankfully most dogs, and it is normally dogs rather than more discerning cats, recover within 24-48 hours although some may take longer until they are completely back to normal.

8 - Corn cobs

This is another item that you will hopefully not be feeding your dog on purpose.  While it is not a poison as such, eating one can have deadly results and so is a worthy addition to this list of dangerous food.   The risk is actually not due to the corn itself, but rather the central cob.  This is a size that can be swallowed but it does not get broken down in the stomach.  Instead, the corn cob passes into the small intestine where there is a significant risk of it getting stuck and forming a complete obstruction.  If this happens then prompt surgery is the only course of action.

To make matters worse is the fact that a corn cob is actually very hard to see on xray which means that an obstruction may well only be diagnosed much later than say a bone or stone causing a similar blockage.  As a result the surgery can take longer and be even more risky.

sweet corn cob
dog chewing on a huge bone
coffee beans

9 - Bones (especially cooked bones)

I know the common response to the next food item.  "I have always given them to my dog and never had any problem".  Or maybe: "Its what dogs would eat in the wild if they were still wolves so don't tell me they are bad".

It's true that lots of dogs may enjoy a regular bone without any problem.  Others will get nothing worse than a serious case of food poisoning.  Others will get nothing worse than a painful fractured tooth.  Others will get nothing worse than a piece trapped across the roof of their mouth.  Others again will get nothing worse than severe constipation due to a build-up of sharp bone shards that can only be cleared with an enema under anesthetic.  And some will get nothing worse than an intestinal obstruction that then develops a hole and they die from septic peritonitis.

Oh wait, those are all actually really bad things and yes, death is on the list.  It happens.  I've seen it.  Cooked bones are worse because they tend to be more brittle and so splinter into sharp, pointed fragments.  Raw bones cause the same problems though, large chunk can be swallowed and the large grinding molars can get broken.  This topic is worth a whole article in itself but until then don't feed your dog bones, and if you do then keep your fingers and toes crossed.

10 - Coffee grounds

Coffee, or more specifically caffeine, can pose a real risk to our cats and dogs.  Caffeine is of course not just found in coffee but also energy drinks, caffeine pills and tea.  While caffeine may be fine for us, at least in moderation, our pets are much more sensitive to it with them suffering from hyperactivity, restlessness, vomiting, a racing heart rate and this can progress to an abnormal heart rhythm, tremors, seizure and of course death.

But how much do they have to get hold of to cause problems?  As always this depends on the size of our cat or dog as well as the type of coffee.  If a pet eats unused coffee grounds then a 10 pound (4.5 kg) cat or dog would only need to potentially eat around 22 grams or 2 tablespoons of a strong variety to be toxic.  For a weak brew this amount could increase to about 56g or 5 tablespoons.  That is still not a huge amount.  Used grounds obviously have a lot less caffeine and so the toxic amount would be anywhere between about 7.5 to 18 tablespoons for our 10 pound pet.

As we are talking about caffeine, a typical caffeine tablet contains 200mg of caffeine and it would only take 3 and a half to be toxic to our 4.5kg pet.  Imagine if they broke into a small pack of 50.  That's enough to be toxic for a 65kg or 150 pound dog !

11 - Vomit Inducers

So that's our top 10 potentially deadly poisonous foods but as a bonus for reading this far here is number 11.  This is a group including salt, washing soda crystals, hydrogen peroxide and anything else that you have found on the internet that may make your dog vomit  Why include these?  Well they are all stay-at-home methods that have been used or advised to make our pets vomit but serious harm can be done.

Too much salt itself is a severe poison and does not reliably cause vomiting, washing soda crystals are often confused with caustic soda with fatal consequences and using too strong a preparation of hydrogen peroxide can severely erode and burn a pets mouth and intestines.  There are also plenty of things that our pet may have eaten where we actually don't want them to vomit.  These include caustic substances, petrochemicals, hydrocarbons or sharp foreign bodies like bone shards.

If a cat or dog has certain conditions then vomiting is too dangerous, generally due to a risk of them breathing vomit into their lungs which again can be deadly.  These conditions might include laryngeal paralysis, reduced consciousness and nervous problems.  There is also no point in making a dog or cat vomit if is is over 2-4 hours since they ate the toxic substance or if they have already vomited.

So what is safe to use?  Well, cats are very difficult to make sick and I would strongly recommend any cat be taken straight to the vet rather than mess around with home remedies that are less likely to work.  In dogs, 3% hydrogen peroxide can be given at a dose of 5 ml (1 teaspoon) per 10 pound (4.5 kg) body weight up to a maximum of about 50 ml, if this doesn't work then it can be repeated after 15 minutes.  If it still doesn't work then do not give more, they need to get to the vet.

Having said that, using this method at home is much less reliable that your vet administering a prescription vomiting drug and so my advise would be to see your vet straight away.  Hydrogen peroxide also works by irritating the lining of the stomach, something you may not want to do if they have certain conditions or if they have eaten certain substances.  Finally, If you use hydrogen peroxide and it doesn't work then you have delayed your dogs treatment by at least 30 minutes which may be critical.  Its also worth considering that even though your pet may look like they have vomited everything, in fact only about half of their stomach contents may have been expelled and so additional treatment may still very much be needed.

 

I hope this article helps to prevent your pet getting into trouble and poisoned in the future.  Prevention is always better than cure!  Make sure too that you check out the companion article discussing the top 10 poisons in the home and garden.  Remember if you have any concerns over something your cat or dog has eaten, your vet should always be the first person you call.

If you have and questions on this topic, comments or ideas for future articles then please comment below.  I would love to hear from you.  Also consider signing up to our newsletter to make sure you don't miss out on any future content.

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