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Why is My Dog Pooping Blood?

5 min read

As dog owners, some of us are a little obsessed with inspecting our dog’s poop. This might sound a bit gross, but having a quick glance is actually a very good habit to get into as your dog’s poop can tell you a lot about their general health.

Just be sure to wash your hands thoroughly after picking up after your dog, because there are some germs and small parasites that can pass to people.

If you notice your dog is pooping blood, it can be incredibly alarming to see. There are a huge range of reasons why this may be happening and we’ve outlined some common ones below, but it’s important to seek help from your vet so that they can make a proper diagnosis and recommend the best treatment plan if needed.

What does blood in dog poop look like?

The appearance of blood in dog poop can really vary, but what it looks like can actually tell you and your vet a great deal about where in the gastrointestinal tract the blood is coming from and can even help to diagnose the root of the problem.

Blood in dog poop generally falls into two different categories both of which can be seen in otherwise healthy-looking stools, or associated with diarrhoea:


This is where the blood is bright red, which means that it is ‘fresh blood’. This will usually indicate that the issue is with the lower digestive tract, such as the colon or rectum. If you spot just a single streak of red blood in your dog’s poop as a one off it may not be a cause to worry, but if this is a regular occurrence or you see a large amount, it’s likely an indication of a more serious problem.


Melena is where the blood in the poop is dark, sticky and tarry and it may even appear almost jelly like. This tells us that the blood has been digested so the problem is probably higher up in the digestive tract.

What if my dog is pooping straight blood?

If it looks like your dog poops straight blood you should contact your vet straight away for advice. One of the reasons this may occur if they’ve had diarrhoea for a longer period of time and the gut is now fairly empty, meaning blood is the only thing left in your dog’s system to come out.

Why is my dog pooping blood?

There are many reasons why your dog will be pooping blood. One of the more alarming is haemorrhagic gastroenteritis. With this condition there will be large amounts of bright red blood and it may appear as though your dog is pooping straight blood at times. It’s more common in smaller breeds and toy dogs and it can be idiopathic (have an unknown cause) or caused by bacterial infections, eating something they shouldn’t have or even a sudden change to the diet. However, haemorrhagic gastroenteritis can also be a symptom of immune-mediated diseases, toxins, pancreatitis and even stress or anxiety.

With haemorrhagic gastroenteritis there may also be other symptoms present such as: vomiting, painful abdomen, lack of appetite, lethargy and fever. If you believe your dog has this condition, contact your vet as soon as possible as a speedy diagnosis and treatment is important.

To learn more about symptoms your dog may have, our useful guide on unusual symptoms to watch out for can help.

Other reasons why your dog may be pooping blood

When your dog is pooping blood, it can be a sign of many other conditions, including:

  • Infections, particularly bacterial gut infections
  • Viruses such as parvovirus
  • Parasites such as intestinal worms
  • Colon cancer
  • Colitis
  • Stomach ulcers
  • Rectal polyp: a mass located just inside the anus
  • Anal gland conditions
  • Constipation
  • Clotting disorders
  • Toxins
  • Liver disease
  • Kidney disease
  • Immune system diseases
  • Hormonal disorders


What if my puppy is pooping blood?

If your puppy is pooping blood and they haven’t had their vaccinations, there could be a chance it’s canine parvovirus. This is a highly contagious virus that affects the gastrointestinal tract, particularly in the small intestine where it destroys cells, impairs absorption and disrupts the gut barrier. It can be spread through direct contact with an infected dog or by coming into contact with a contaminated object. The effects of this virus can be wide-reaching; it can affect the production of immune cells by the bone marrow and can even lead to heart problems.

The good news is that there is a vaccine for canine parvovirus which puppies should receive with their course of puppy vaccines. Although no vaccine is 100% effective, it significantly reduces the risk of them catching canine parvovirus once they are fully vaccinated. This is one of the reasons why you should avoid taking them outside until they’ve received their full course of vaccines.

Common symptoms of canine parvovirus include: bloody diarrhoea, vomiting, fever, lethargy, weight loss, weakness, dehydration and depression. If your puppy is pooping blood, take them to the vet as soon as possible for diagnosis and treatment. This is particularly important in puppies as they are at higher risk of becoming rapidly dehydrated.

What should I do if my dog’s pooping blood?

Contact your vet for advice. If possible, it’s a good idea to bring a fresh sample in a clean, leak-proof container for testing as this may help your vet make a diagnosis. If this isn’t an option, take a picture to show your vet. As mentioned previously, the way your dog’s poop looks can give some useful information. Even if there’s blood in your dog’s stool and they’re acting normal, it’s a good idea to contact your vet and have your pet checked out just to be on the safe side. Catching an underlying condition early will give your pet the best chance of receiving successful treatment.

How is blood in dog poop treated?

As the causes of blood in dog poop vary so much, so does the treatment. Your vet will firstly carry out diagnostic tests which can include blood, urine and stool testing and they may also want to do X-rays and ultrasounds.

If your vet determines that it is dietary related, a therapeutic bland diet may be recommended, alongside probiotics to support gastrointestinal health. For dogs with diarrhoea, fluids may need to be given to treat severe cases of dehydration.

Now you know the possible reasons why your dog is pooping blood. Want to learn more about your dog’s poop? Read our guide next!