My Dog Licked Some Motor Oil


Are you having a bad day?

Have you just seen a suspicious dark puddle under your car and just as you think that things can’t get worse, your dog strolls over and starts drinking from the puddle.

And now on top of that car repair bill, you can see dollar bills from an emergency vet’s bill swimming before your eyes.

But if your dog has just liked some motor oil, how serious is it and what should you do?

[1] My dog licked motor oil, what should I do?

Because motor oil is always toxic and can be fatal, you need to get an appointment with your vet or phone the pet poison helpline. 

Is motor oil toxic to dogs?

Motor oil is incredibly toxic to dogs.

According to the petroleum company Total, there are three types of motor oil- mineral, synthetic and semi synthetic.

Each of these different oils contain different additives that are added to improve the performance of the oil when it is used in cars. 

These additives are just different chemicals- none of which are good for your dog. 

These additives include corrosion inhibitors, detergent additives and most worryingly antifreeze additives.

To cut to the chase, antifreeze is known to be lethal to dogs- it is called ethylene glycol poisoning.

If a dog ingests enough of it, then without treatment, that can die from kidney failure within 12 hours. 

A lethal dose for a dog is thought to be a tablespoon or two but that is a rough estimate which doesn’t take into account the size of your dog or any pre existing medical conditions that they might have. 

It could be worse?!

It’s not all doom and gloom though.

Although motor oil contains antifreeze, as an overall percentage it is quite small because there are so many other ingredients in motor oil.

Especially if your dog has only licked a bit of motor oil.

Car radiator coolant is the most dangerous because it can be made up entirely of ethylene glycol.  

Symptoms of ethylene glycol poisoning

There are three recognised stages of ethylene glycol poisoning

130 minutes ingestionLethargy | Vomiting | Inco-ordination
212- 24 hours laterDogs seem to improve? Increased heart rate
33 days laterLethargy | Vomiting | Seizures

And what I haven’t described is that stage three includes death as the kidneys stop working completely. 

And now having looked at the very worst case scenario of ethylene glycol poisoning, I will move on to look to see if there are any differences between unused and used motor oil.

Unused motor oil vs used motor oil

Everything that I have described up to this point relates to unused or clean motor oil.

But how does used motor oil compare to unused motor oil and how could this affect your dog?

It is hard to believe but if your dog has licked used motor oil, it is even more poisonous.

Yes, incredible isn’t it?

Used motor oil contains most of the additives and poisons described about as well as heavy metals such lead, zinc and barium

Not only that but some of these heavy metals might be present in used oil as tiny slivers of metal

They won’t just poison a dog but potentially cut the lining of various organs as they travel through your dog’s body. 

Motor oil isn’t unfortunately the only type of oil that you dog might lick or ingest.

In the next section, I will talk about some others and see if they are just as dangerous. 

Motor oil vs lighter fluid vs WD40 vs cooking oil

Firstly, let’s take a look at lighter fluid.

Lighter fluid

Lighter fluid is made with a mixture of gases and liquids including benzene, naphtha and propane.

Like motor oil all of these are derived from crude oil

And these gases and liquids are all hydrocarbons and poisonous to a dog.

The strong smell of lighter fluid kind of hints at how poisonous it is. 

But that can be one of the attractions for a dog because the odour is so strong. 

Lighter fluid poisoning occurs when too much of it is inhaled or ingested.

Some people deliberately inhale lighter fluid fumes in order to get “high”. 

Dogs won’t deliberately inhale lighter fluid fumes but they can accidentally inhale too many of these fumes if they are in very confined spaces. 

Neither do they deliberately ingest lighter fluid but this might happen if they accidentally bite into a “cigarette lighter”. 

A few of the symptoms can include severe pain in the throat and can lead to dizziness or comas.

If your dog ingest lighter fluid then you should phone the vet immediately. 

WD40- liquid lubricants

Next up is WD40.

WD40 the famous liquid lubricant is mostly specific hydrocarbons, labelled as aliphatic or oil like

It contains very similar liquids to lighter fluid such as naphtha

Like lighter fluid, it is hard for a dog to get “easy access” to WD40 because it is locked up within a spray can and only comes out in small amounts as it is sprayed onto this or that piece of machinery. 

But it remains as poisonous and if you think that your dog has ingested a significant amount 

Cooking oil

Cooking oil is as different to lighter fluid and WD-40 as they are similar to each other.

Crude oil originates from dead animals that died millions of years ago, cooking oil originates from plants, such as sunflowers which were processed a matter of weeks ago.

Cooking oil is safer for a dog to ingest than lighter fluid or WD40 because it doesn’t contain any harsh chemicals (hydrocarbons.) 

But there are dangers.

It is easier for a dog to ingest much larger quantities of cooking oil (than lighter fluid or WD-40) because the bottles that it comes in are much bigger.

But a dog can still be poisoned by cooking oil. 

Large quantities are liable to overload a dog’s pancreas, which plays a key role in a dog’s digestion. 

How can I stop my dog from licking motor oil?

Like any harmful substances, the best way to stop anyone or a dog from licking or ingesting motor oil is to make sure that it is kept securely.

Dogs who are owned by people who work or tinker a lot with cars are more at risk than the rest of us.

This can be as simple as making sure that when you are working around a car, don’t let your dog anywhere near.

And make sure that you tidy or clear up after yourself.

Which is easier said than done. 

There are times when despite your best intentions, you will get distracted or not have enough time to clear up properly. 

Alternatives to motor oil

One of the troubles with owning a car is that you need motor oil because there is no other way of effectively keeping your car’s engine running.

If you want to keep owning a petrol or diesel car that is.

The only other choice that you have is to switch to an electric vehicle because their engines don’t require motor oil to help them work. 

But since electric cars are still very expensive for most of us, it might be better to try and keep any motor oil out of harm’s way for now…

James Grayston

My name is James and I love dogs. have owned four Golden Retrievers in the past 15 years. Currently I own two "Goldies"- a five year old and a seven month old. The photo shows me with our youngest when she was about 7 weeks old!