There are many many things that can cause your dog to throw up, so it’s hardly surprising that it is one of the most common reasons for a pet to be brought in to see the vet.

First though the question a vet has to answer – is your dog really throwing up?

Sometimes our dogs can look an awful lot like they are being sick, but actually they are doing something else – there is a subtle difference between vomiting, which is common in humans, and regurgitation. These two behaviours both look similar, and both result in your dog bringing up food or stomach contents, but they can have very different causes.

So to start with, your vet may ask questions (sometimes accompanied by impressions and noises if you are unlucky) to find out if your dog is truly vomiting, or regurgitating. Videos on smartphones can be really helpful – and may save you having to watch your vet’s impressions act.

Once we have established that your dog is vomiting, there are so many things which can cause sickness that veterinary textbooks can cover multiple pages with one long list of different diseases!

However, despite there being many reasons a dog might be throwing up, these causes can be grouped together into a number of categories.

Throwing up due to something they’ve eaten

This is what we as vets describe as “dietary indiscretion” – essentially this is when a dog has eaten something they shouldn’t have, or which disagrees with them. Many different events can fall into this category, including raiding the rubbish bin or eating something rotten, eating an object like a corn on the cob, bone fragment, or piece of a toy which becomes a “foreign body” stuck in the stomach, or eating something poisonous or toxic.

Sometimes dogs may also eat a very rich, or fatty meal and initially seem well, but then the fatty meal can cause inflammation of the pancreas – the organ which responds to digest such rich meals – causing what we call “pancreatitis”, and often the first sign of this problem is vomiting.

At this time of year, rich or toxic food also needs to be considered – see my colleague Kate’s blog on this

Could it be an infection or disease?

Infections can be from tiny, microscopic invaders like bacteria and viruses causing gastroenteritis, as well as bigger attackers like parasites such as worms. Just like in humans, all of these can be causes of vomiting.

Our third category gets a little bit more complex – it’s what vets call “Metabolic or endocrine diseases”.
This category is made up of diseases within the body which affect the balance of some hormones or other processes which can cause sickness and vomiting. Examples would be kidney disease, or liver disease. These causes of vomiting can be subtle and often require testing to detect.

A host of other diseases can cause vomiting, such as infection in the womb of older female dogs (known as pyometra), or even occasionally in older dogs sadly cancer can cause vomiting.

There are other less common categories and causes of vomiting, but the examples above are good demonstration of how broad these can be.

When should you bring your dog to the vet?

In fact, some of these conditions can be easily managed, whilst others can quickly become life threatening.

Your vet will likely examine your pet thoroughly, and ask you a lot questions in order to get a picture of what’s happening. This is what helps a vet prioritise which causes may be more or less likely.

For example in a vomiting puppy your vet may ask about vaccinations. On the face of it, this might not seem very helpful for vomiting. But actually Parvovirus is a common cause of vomiting in young dogs, and vaccines help protect your pet, so if they had all their injections at the right time, Parvovirus can move down the list as not very likely.

What tests will the vet perform?

Your vet might also recommend performing some tests to investigate the cause of vomiting. This might include blood tests, which can help detect infection, or metabolic disease. Or X-rays (sometimes called radiographs) to look for signs of a foreign body. Potentially even taking a stool sample to look for parasites. It can also be appropriate, if your dog is relatively well and comfortable, to follow a simple treatment plan to help your pet feel better, and wait and see how they respond to that plan before proceeding to testing.

Your vet will talk to you about what they find, and what they are concerned about, so that together you can make a decision on the best approach at the time for you and your dog.

If your dog has been, is, or might be vomiting, please talk to your own vet for advice. They can talk to you about what’s happening, and arrange an apportionment if needed to examine and take the best care of your dog.

Remember, for any health concerns you can use our free Dog Symptom Checker.

You may also be interested in;