Seeing blood in your dog’s stool can be scary, especially if it has never happened before. Whether your dog is a puppy, or has been with you for years, seeing blood in your pooch’s stool is extremely distressing.

Understanding the different types of bloody stool (and what may be causing it) is critical in understanding the health of your pup. Once you understand what might be happening, you can take action to help your best buddy feel better again.

Bloody Stool in Dogs: What to Look For

bloody stool in dogsBloody stool can have two distinct characteristics, and knowing the difference will help you – and your vet – identify what may be ailing your dog.

There are two main types of bloody dog stool: hematochezia and melena. Hematochezia is characterized by its bright red color.1 Bright red stool indicates that your dog may have bleeding in their lower digestive tract or colon. Prior to seeing the blood in your dog’s stool, you may also notice that your dog cries, or whimpers, when trying to go to the bathroom – or that they have diarrhea that has a mucus consistency.

Also, be on the lookout for bloody stool that is more black and tar-like. If your pooch is passing stool like this, they may have melena. Melena is defined by its dark color and sticky texture. Melena can occur if the dog is digesting or swallowing blood, which usually occurs higher up in the digestive tract.2

What Causes Hematochezia and Melena?

A lot of health issues can lead to hematochezia and melena symptoms in your dog. Parasites, rectal, colon, and extra-intestinal diseases are all common culprits, and each of these problems has its own root cause.

Rectal and anal diseases can lead to bloody stool in your dog. They are characterized by one, or many, of the following issues: rectal polyps, something lodged in the anus or lower colon, or traumas – such as bite wounds from another animal. While rectal polyps rarely occur in dogs, your veterinarian can feel them during an examination.3 If you think you see any of the symptoms of rectal or anal disease, consult your vet as soon as you can.

What Are Some of the Diseases and Conditions I Should Know About?

There are a few specific intestinal or colon diseases and conditions you should be particularly aware of. Make sure you pay special attention if you notice your dog passing diarrhea or feces with a mucus-like consistency.


Parvovirus is a common disease that can be fatal to dogs if not caught early on. “Parvo” is highly contagious and can be passed through direct contact with another dog, feces, exposed surfaces (such as food bowls, crates, collars, and leashes. And since it can withstand extreme temperatures (both hot and cold) it’s one resilient disease.4 Aside from bloody diarrhea or mucus feces, signs your dog may have been exposed to parvo include lethargy and bloating. The best way to find out if your dog has parvo is to consult your vet and have them conduct a fecal test. The good news is that a vaccination exists for parvo, so if you’re a new puppy parent, be sure to ask your veterinarian about the parvo vaccine.

dog diseases and conditionsHookworms

Blood in the stool, or bloody diarrhea, can be a sign of hookworms. Hookworms are parasites that infect the intestinal tract of your dog, and they are easily transmitted. Hookworm eggs live in passed fecal matter, and they can infect the nearby environment, which means if your pooch walks on the infected ground, or eats the infected feces, they could become exposed.5

Hookworm larvae can also pass through the skin. From there, the parasites can travel through your dog’s blood and into his lungs. Your dog may then cough up the larvae and swallow them again – where the hookworms will mature in your pup’s small intestine. Since the mature hookworms then feed by bloodsucking, dogs – especially young puppies – may become anemic quickly. This is a serious health issue that warrants a vet trip as soon as possible. If you think your dog may have hookworms, your vet can run a lab test of a fecal sample to know for sure. Thankfully, for you and your dog, treatments exist to eliminate hookworm infections in dogs.6

Only the Best for Your Pup

Blood-red and mucusy stool can certainly be alarming, and things like parasites, hookworms, and parvovirus all sound pretty scary. The symptoms, if not treated, are frightening – and can even be fatal. But you and your pupper can both sleep better at night, knowing that there are treatments, preventative care options, and vets who know what to look for – and exactly what to do.

So, do your due diligence. If you notice your pup having bloody stools, talk with your vet. Veterinarians are trained to diagnose a variety of diseases and conditions in your pup – and treatments are available that will have Fido feeling better in no time!

Learn More About Pet Health:
7 Reasons Why Your Dog’s Vomiting White Foam
Mucus In Your Dog’s Stool: What’s Normal, What’s Not?