Noticing your dog has diarrhea with blood in it can be alarming for even the most experienced dog parent. Integrative veterinarian Dr. Julie Buzby explains how to recognize blood in your dog’s poop (it isn’t always as easy as you may think), why dogs get bloody diarrhea, and what to do about it.
The occasional bout of diarrhea is fairly common for most dogs, and not necessarily a cause for concern. However, dog diarrhea with blood is a different story. While there are a variety of less worrisome causes of bloody diarrhea in dogs, some conditions that cause blood in your dog’s stool have the potential to be life-threatening.
Before we can discuss the causes though, it is important for all dog parents to be on the same page regarding what constitutes bloody diarrhea.
What does dog diarrhea with blood in it look like?
Simply put, bloody diarrhea is soft or liquid stool that contains blood. But here is where it gets a bit more complicated. Sometimes blood doesn’t look like blood.
If the blood comes from the upper digestive tract (stomach or upper small intestines), it gets digested as it makes its way through the rest of the GI tract. Therefore, instead of being a red liquid, blood that is digested or swallowed is black and tarry. This means that melena, or stool that contains digested blood, is typically dark, sticky, and at least semi-solid.
On the other hand, sometimes bloody diarrhea does contain the classic bright red blood. This is known as hematochezia, and it is a sign of bleeding in the lower digestive tract or colon. The blood still looks like blood because it hasn’t had time to get digested. Sometimes there will be just a streak of blood on the outside of the stool or a few drops of blood in the diarrhea. Other times, the dog may be passing a bloody liquid, blood clots, or even straight red blood.
What causes a dog to have bloody diarrhea?
There are a range of reasons a dog may have bloody diarrhea or be pooping blood. Some of the more common include:
1. Intestinal infections
Intestinal infections can cause your dog to have an acute onset of diarrhea with blood. Dogs may develop intestinal bacterial infections from exposure to harmful bacteria such as Salmonella, Campylobacter, and E. coli. The risk of exposure to these bacteria is especially high with raw food and raw diets.
Additionally, intestinal fungal infections like histoplasmosis are also possible. Plus, canine parvovirus, canine distemper virus, and other viral infections can cause bloody diarrhea.
Unfortunately, parvo and canine distemper can both be fatal if left untreated. Especially if you have a young or unvaccinated puppy with severe vomiting and diarrhea, don’t waste any time getting to the vet.
2. Intestinal parasites
Various internal parasites can make themselves at home in your dog’s digestive tract. Some parasites like hookworms, roundworms, whipworms, and tapeworms can cause enough inflammation in dogs’ guts that it is possible for there to be blood in their stool. Protozoans such as Giardia can also cause profuse diarrhea in dogs.
3. Dietary indiscretion or diet change
Dogs who go “counter-surfing”, dig through trash, or otherwise eat something they shouldn’t have are at risk for developing diarrhea, which may be bloody, watery, or explosive. Additionally, they might start vomiting due to gastritis in dogs (i.e. stomach irritation).
Along the same lines, even rapidly changing your dog to a new food or giving a new treat can be enough to cause diarrhea. Sometimes the diarrhea may even contain blood.
4. Toxins or medications
Certain plants, foods, or chemicals can be highly toxic for dogs when ingested. And taking some medications (e.g., antibiotics, NSAIDs, steroids, chemotherapy) could cause bloody diarrhea, even at prescribed dosages.
5. Stress colitis
Stress colitis in dogs (i.e. irritation of the colon due to stress) is one of the most common causes of dog diarrhea with blood and mucus. Anxiety-provoking events such as visitors, changes to the house, staying at the boarding kennel, loud noises, etc. can all cause stress-induced bloody diarrhea.
6. Hemorrhagic gastroenteritis
Dogs can develop a scary condition called hemorrhagic gastroenteritis (HGE), also called acute hemorrhagic diarrhea syndrome (AHDS). Affected dogs will have rapid-onset bloody diarrhea which leads to severe dehydration. Plus, they may also be vomiting, and the vomit may contain blood too.
Left untreated, hemorrhagic gastroenteritis can sometimes be fatal. However, thankfully, with appropriate treatment, most dogs make a full recovery.
7. Stomach ulcers
A bleeding stomach ulcer in dogs can cause melena (i.e. dark tarry stool). Additionally, the dog may be experiencing abdominal pain, poor appetite, or nausea.
8. Other disease processes in the body
Health issues elsewhere in the body can lead to bloody stool in dogs plus other clinical signs. Some of these conditions include:
- Liver disease in dogs
- Kidney disease in dogs
- Pancreatitis in dogs
- Addison’s disease in dogs
- Inflammatory bowel disease (IBD in dogs)
- Cancer
- Immune-mediated thrombocytopenia (ITP in dogs), rodenticide ingestion, or other problems with blood clotting
9. Anal gland problem or rectal masses
Since the openings to the anal glands are located at the edges of the anus, anal gland issues in dogs such as an anal gland abscess or infection can cause streaks of reddish blood on the outside of the stool. In this case, the blood is coming from the anal gland itself, not the digestive tract.
Along the same line, a bleeding rectal mass in dogs can also cause blood on the stool or even straight blood coming out of the rectum.
10. Dyes that color the stool red
If a dog chews up a red marker or crayon, gets into cupcakes with red frosting, or eats dog food or treats with red dye in them, it is possible that the stool may have an orangish or reddish tint. This is just due to the red dye and is not real blood. However, it can definitely cause a moment of confusion or worry until you realize what has happened.
What if your dog has diarrhea with blood but acts fine?
For some of the conditions above, your dog might have diarrhea with blood in it but act fine otherwise. This can make it a little challenging to sort out what to do next. However, in general the safest thing you can do is to call your vet or make an appointment for a vet visit if your dog has bloody diarrhea.
Sometimes a dog may seem fine initially but then become dehydrated as the diarrhea progresses. Or the dog can lose enough blood to become anemic. As I like to say, “Better safe than sorry.” In other words, it is wise to call your vet if your dog is having bloody diarrhea, even if you aren’t seeing any other symptoms at the moment.
When is bloody diarrhea an emergency?
Other conditions in the list above can quickly become life-threatening. Thus, it is especially important to promptly seek veterinary care if you notice these symptoms:
- Pale gums—One of the most common signs of anemia in dogs (i.e. low red blood cell count) is pale gums. If your dog has lost enough blood in the diarrhea for his or her gums to be pale, this is an emergency. Additionally, shock can also cause pale gums and is life threatening too.
- Large quantities of blood in the diarrhea—A small smear of red blood on the stools or in the diarrhea may not be a big deal. But if the dog’s diarrhea appears to contain a lot of blood or is mostly blood, this warrants an emergency vet visit.
- Lethargy—If your dog is suddenly laying around more, acting tired, or is otherwise being a lethargic dog, this could signal a more serious issue.
- Weakness—Dogs who are in shock or have lost a significant amount of blood may be weak or have trouble standing up. They are in need of immediate medical attention.
- Signs of dehydration—Dry or tacky-feeling gums, sunken eyes, a dry nose in dogs, or skin that stays tented when picked up may all indicate your dog is dehydrated and it is time to get the vet involved.
- Additional symptoms—Signs like vomiting, abdominal pain, poor appetite, changes in water consumption or urine volume, etc. may also point to a health condition that requires more immediate treatment.
How will the vet diagnose the cause of the diarrhea?
During the vet visit, the goals will be to assess your dog, attempt to find the underlying cause for the bloody diarrhea, and develop a treatment plan The veterinarian will usually start with a physical exam and detailed medical history.
During the exam, the vet will pay particular attention to your dog’s hydration status and abdominal palpation. He or she may also suggest a rectal exam, especially if your dog’s diarrhea contains a lot of fresh red blood. While evaluating your dog, the vet may ask you questions about your dog’s current foods, treats, medications, travel history, and any recent exposures to new things.
Sometimes that is all it takes to reach a diagnosis. Other times, the vet may suggest some additional diagnostic tests. Fecal tests for dogs are often a good next step because they let the vet check for intestinal parasites. After all, parasites are quite common, and common things happen commonly.
If the cause of the bloody diarrhea still isn’t clear, additional testing such as blood tests for dogs, X-rays, and ultrasound may be necessary.
How will the veterinarian treat bloody diarrhea in dogs?
The cause and severity of the diarrhea will help dictate the treatment plan. Sometimes the vet will be able to directly address the underlying cause plus provide supportive care. Other times, therapy is aimed primarily at supporting the GI tract and helping it heal.
Since the cause-specific treatment can vary, we will focus on the general treatment for bloody diarrhea.
Hospitalization
If your dog is experiencing severe, prolonged diarrhea and large volume blood loss, he or she may require hospitalization, fluid support, and possibly blood transfusions.
However, if the bloody diarrhea is more mild, the vet may recommend treatment at home.
Subcutaneous fluids
In cases where the dog is dehydrated but not sick enough to stay in the hospital, the vet may administer subcutaneous fluids for dogs. This fluid boost provides some short-term rehydration and helps the dog feel a bit better.
Probiotics
In many cases, a dog’s diarrhea will resolve after 5-7 days, especially with probiotics and a bland diet. Probiotics are helpful because they can compete with harmful gut bacteria for space in the intestines. Plus, they help increase the numbers of “good” gut bacteria that keep dogs healthy.
Bland diet
Bland diets for dogs make less work for the intestines because these foods are easy to digest yet packed with essential nutrients. You can purchase a commercially-available bland diet from your vet or you can cook your own. This is typically a diet of boiled skinless and boneless chicken with no seasoning or oils. Boiled ground turkey is also acceptable, and both are typically mixed with plain cooked white rice.
However, keep in mind that most home-cooked bland diets are not complete or balanced, so they should not be fed to dogs long term.
Dewormer
Additionally, vets often prescribe anti-parasitic medications like dewormers for dogs with bloody diarrhea, even if initial fecal testing is negative. This is because some parasites do not continuously leave eggs in the stool to be detected on a fecal exam.
Fiber supplements
Some types of bloody diarrhea respond well to adding fiber for dogs to the diet. Canned pumpkin for dogs does provide some fiber, but it may not be enough. Thus, the vet may recommend a powdered fiber supplement like Metamucil for dogs. (Safety note: Only use plain unflavored Metamucil. Flavored versions, gummies, or chews may contain the sugar substitute xylitol (birch sugar), which is toxic for dogs.)
Antibiotics
Most of the time, dogs with bloody diarrhea don’t need antibiotics. However, they can be useful in situations where the vet suspects a bacterial infection.
Are there home remedies for a dog’s diarrhea with blood in it?
If your dog is only having diarrhea with a small amount of blood in it but is acting fine, or if you are waiting for the vet appointment, there are a few things you can try in the meantime. As mentioned, a bland diet for dogs and probiotics can be a good place to start. You could also consider adding some canned pumpkin to your dog’s food to provide extra fiber.
Keep in mind though that if the diarrhea worsens, there is more than a tiny amount of blood in the diarrhea, your dog is acting lethargic or sick, or you have any concerns about your dog’s status, please reach out to your vet promptly or head to the nearest veterinary ER.
What about Pepto-Bismol or Imodium for bloody diarrhea in dogs?
While they work for humans, it is best to avoid giving your dog medications like Pepto-Bismol® and Imodium® (loperamide) unless directed by your veterinarian. The ingredients in Pepto-Bismol for dogs are not easily metabolized in dogs and can cause further stool issues. And Imodium slows down gut motility significantly, which is not safe if your dog potentially has an infection or has been exposed to toxins.
Call your vet if your dog has bloody diarrhea
While most dogs recover well from diarrhea with blood when given the appropriate treatment, sometimes it can be life-threatening. So even if your dog has bloody diarrhea but is acting fine, it is still safest to give your vet a call.
And if your dog has diarrhea with blood in it and seems sick or weak, or if there is a lot of blood in the diarrhea, don’t delay in getting help for your dog. This might mean taking your dog to the emergency vet if your vet isn’t open or available.
With prompt treatment by your veterinarian and some TLC from you, hopefully your dog’s scary episode of diarrhea with blood in it will soon be a thing of the past.
Has your dog ever had diarrhea with blood in it?
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