Why Is My Dog Pooping Blood?

Blood in your dog’s stool is never a good sign. It points to a problem in the gastrointestinal tract, the pathway through which animals get their nutrition and source of energy. Some require the immediate attention of the vet, while others might not. But because this pathway is so fundamental to your dog’s health, even those that are not life-threatening at the moment are likely to become so if left untreated.

How Does Blood In The Stool Look Like?

You may think the answer is pretty obvious: if there’s something red among the brown, it’s got to be blood right? But the blood that comes out of the alimentary canal doesn’t always look like the bright red liquid that comes out of a cut on the skin.

If it does, the term for it is hematochezia. It indicates that the blood is fresh, so most likely it came from the latter parts of the gastrointestinal tract (so the parts closest to your dog’s butt). It can be streaked on the poop or come out as discrete droplets.

But if you see black, tarry, goopy substance in your dog’s poop, that could be blood as well. It’s called melena, and it indicates that the bleeding is coming from somewhere higher up the gastrointestinal tract. It is no longer red and liquid because it has been processed by the stomach or small intestines.

There are also times when the redness in the poop isn’t blood at all. If your dog has eaten something with red food coloring or red dye, it will show up in his feces. If you are not sure if that substance is toxic or not, check in with your vet.

If you have trouble visualizing the color, put a piece of the stool on a white paper towel and see if it stains red or mahogany brown to black. Take a couple of pictures of the poop (gross, but very helpful) so you can show it to your vet.

Remember that the color of poop reflects its diet, so different dogs can excrete different colors. If you know how your dog’s stool looks like on a normal basis, you should be able to tell if something is wrong with it.

Possible Reasons Behind Bloody Dog Poop

Blood in your dog’s poop could be caused by a number of factors. The only way to know for sure is to consult your veterinarian. They will have the equipment needed to run diagnostic tests and the expertise to interpret the results. But to help them get to the bottom of this (no pun intended), they will need your help.

It is important for you to be familiar with the possible causes of blood in your dog’s poop so you can provide the information your vet might need during history taking. This can help them narrow down the long list of possible causes, cutting the time and resources needed to give your furry best friend the treatment he needs.

Intestinal Obstruction

If your dog has a history of eating things he shouldn’t, this might be the root of the problem. The intestinal lumen is much more narrow that that of the stomach, so things may get stuck there. If the object is sharp or too big, it could cause bleeding. This may be accompanied by vomiting, diarrhea, and loss of appetite. Your dog might also be behaving differently because of the pain and discomfort of having something lodged in his gut.

There are times when dogs pass out the obstruction on their own. However, if you don’t see anything coming out with your dog’s poop aside from more blood, then it’s time to go to the vet.

Viral, Bacterial And Parasitic Infections

To the eternal consternation of dog owners everywhere, it is near impossible to prevent our fur kids from licking, sniffing, and eating things they shouldn’t. Given that, a vast majority of dogs already have unwelcome guests living somewhere in their bodies. Vaccination, deworming, and ectoparasite treatment help your dog’s immune system fight off heavy infections that could jeopardize your dog’s life.

When viruses, bacteria, and parasites replicate and overcome your dog’s defenses, they can attack walls of the alimentary canal in an attempt to enter the body. In doing so, they cause ulcers, abscesses, necrosis, and sloughing off of the gut lining. Symptoms usually include bloody poop, weight loss, lethargy, inappetence, vomiting, and diarrhea. When you see more than one of these signs together, bring your dog to the vet immediately. It takes time for infections to show observable signs of disease, so when it does, you know it’s already serious.

Your dog is at higher risk for infection if he has missed a vaccination or deworming session if he frequently goes outside with no flea/tick prevention measures if he has been exposed to infected animals or their waste.

Another crucial factor to consider is your dog’s immune status. Stress and poor nutrition could lower his body’s natural defenses.


Neoplasms can be benign tumors or malignant cancers. Either way, these present problems for your dog. Benign growth can obstruct the lumen of the gut, making it difficult for food to pass through and stretching the intestinal walls taught. Cancerous growths not only cause blockage but also present the possibility of metastasis or spreading to other organs.

Symptoms associated with neoplasm are often chronic in nature. If you notice your dog has been vomiting, experiencing diarrhea, and appears to be getting thinner over time, it may be a sign of neoplastic growth.

Tumors are serious, but it is important to stay calm. Advances in veterinary medicine have helped pets improve their quality of life despite this condition.

Existing Medical Conditions And Treatment

Blood in your dog’s poop may be a symptom of a systemic disease rather than one confined to the stomach and intestines. It could indicate a problem in one of the nearby organs (such as the liver or the pancreas). Blood clotting disorders may also present as bloody stool, as the body fails to repair breaks in the mucosa and blood just keeps flowing out.

Existing bacterial, viral, or fungal infections in other parts of the body could bring down the immune system and make it easier for other pathogens to enter through the gastrointestinal tract. Chronic use of immunosuppressant drugs has the same effect. Strong antibiotic treatment that is meant to fight off an existing infection could go overboard and kill off the beneficial microbes that protect the gut from pathogens.

There are many complex interactions between the different parts of an animal’s body, some of which are not even fully understood yet. That’s why it is essential to tell your vet about your dog’s recent or existing medical conditions and the drugs administered to fight it.

What To Do Next

There are times when bloody poop resolves itself on its own. If your dog is acting normally and eating well, you may wait for the next potty break to see if there is a need to go to the vet. If it happens again, visit the clinic regardless of how healthy your dog appears.

However, if your dog is less than six months old or advanced in age, don’t wait for more obvious signs to appear. Animals that are very young have underdeveloped immune systems, while animals that are old have impaired ability to repair any bodily damage.

If your dog’s poop is bloody and you notice other signs such as lethargy, poor appetite, vomiting, or diarrhea, you do not need to wait for another incident. Go to your veterinarian right away.

Either way, keep in mind the possible causes of blood dog poop and give your vet as much information as you can to help them resolve the case.

And when they do, you won’t believe the happiness you’ll feel as you pick up good old plain brown dog poop once again.

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Regina Ranada

Regina graduated with a degree in Psychology and worked in Human Resources for four years before she decided to pursue her dream of becoming a veterinarian. She is interested in companion animals and wildlife medicine. She sidelines as the social media manager of her pitbull, Pablo.

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