Brown dog in the grass
© Pixabay

Your dog is vomiting blood? Here's why

By G. John Cole Content Writer

Updated on the

What could be more distressing than to find a dog vomiting blood? Well, firstly you will need to calm down: it might not be as serious as it looks. But whatever is going on, you need to get your pukey dog to the vet.

There are many possible causes when you catch your dog throwing up blood. Thankfully it is a rare occurrence. But you need to get the matter addressed professionally, as even the less serious causes of blood in dog puke require medical attention.

Dog vomiting blood: a reason to worry?

Dogs vomit a lot. It’s no wonder, when you consider what they’re willing to eat if they can get away with it. And when they’re not eating whatever they can find, they’re generally licking, sniffing, or toying with all sorts of unmentionable stuff. This is their vice and we allow them it because they are so wonderful in every other way.

But there are certain types of dog vomit that are more cause for concern than others. Blood in dog vomit is one. Continuous or chronic vomiting – even without blood – is another. Or if his vomiting comes with other symptoms such as weight loss or lethargy.

Likewise, bloody poo or diarrhoea should be taken very seriously.

Dog vomiting blood: possible causes

You can’t be sure the cause of your dog’s bloody vomit until you take him to the vet. Do so quickly, because if he is bleeding internally things could go downhill very fast.

But here are some of the results you might expect to hear.

Stomach cancer

We’ll start with the big one. Unfortunately, bloody vomit can be a sign of stomach cancer. And according to experts, by the time symptoms start, the outlook is not good.

Act as fast as possible. It may still be possible to prevent the spread of cancer. And even if not, you need to make your dog as comfortable and healthy as possible.

Cancer is just one possible cause of vomit in a dog’s blood, so don’t panic – act with urgency, not haste.

Stomach ulcers

There are many possible causes of stomach ulcer, which can begin to bleed if it gets worse.

An ulcer can be caused by poisoning (for example, if your dog has eaten rat poison). But it could also be the result of bacteria, viruses, or a bad reaction to medication.

Organ failure, trauma (such as being hit by a car), or a dietary mismatch can also be a cause of stomach ulcers. In fact, they can even be caused by over-strenuous exercise.

The lining of your dog’s stomach is a delicate thing.

Kidney or liver disease

Your dog’s kidneys and liver help to process the blood, nutrients, and waste matter that flow through his body. When one or the other of them stops working properly, it can throw his whole system into chaos.

With his system out of balance like this, it is not unusual for a dog to puke blood.

Hemorrhagic Gastroenteritis

Hemorrhagic Gastroenteritis is a disease of the stomach that can lead to bleeding, which comes out through vomit or at the other end. It can also cause other issues such as kidney failure, which also lead to a dog vomiting blood.

Unfortunately, nobody knows the precise reason for this illness to develop. However, reducing your dog’s stress levels and ensuring he has a healthy, regular diet, may help to prevent it. All the same, if your dog vomits blood then he has something wrong with him already: so you should take him to the vet if he needs treatment for Hemorrhagic Gastroenteritis or something else.


Inflammation of the stomach lining is known as gastritis. It happens quite a lot. If you hear your vet call it ‘acute gastritis,’ this refers to the fact that it has come on quickly; ‘chronic’ means it’s developed slowly.

Again, this issue could be a problem of its own, or it could be caused by any of the above. It might just be that your dog’s diet is too acidic, or it could be that he ate something daft.

As long as gastritis isn’t too far developed, and it’s not a symptom of something else, it needn’t be too serious. But you need to get it checked out and managed before it gets worse.

Other possible causes

The stomach is a delicate and complex thing. There are many reasons your dog might be vomiting blood, and many of them are connected. In addition to the above, it could be a result of a hormonal imbalance, heartworm, irritable bowel syndrome, parasites, or a clotting disorder.

So it’s time to get him checked out so you can be sure!

More advice on...

What did you think of this advice article?

Thanks for your feedback !

Thanks for your feedback !

Leave a comment
Connect to comment
Want to share this article?