Bloody Diarrhea in Dogs

Published Mar. 21, 2024
A Jack Russell Terrier sits in the woods.

Lubo Ivanko/iStock / Getty Images Plus via Getty Images

What Is Bloody Diarrhea in Dogs?

Bloody diarrhea in dogs refers to a dog’s stool that is watery and contains blood, which may appear red or black.

Bloody diarrhea is caused by irritation and inflammation within the gastrointestinal (GI) tract that leads to blood being released. Red blood is present when the GI issue is located within the colon (large intestines). In contrast, black-colored diarrhea occurs when there’s an issue higher up in the GI tract, such as in the stomach or small intestines, where blood may be digested and turn black or tarry.

When mucus is present, it usually means that the GI issue is within the colon. Jelly-like diarrhea occurs when severe inflammation within the colon causes a significant amount of mucus to mix with the diarrhea.

When dogs have bloody diarrhea, they typically strain to defecate due to discomfort and the constant feeling of needing to relieve themselves.

Health Tools

Not sure whether to see a vet?

Answer a few questions about your pet's symptom, and our vet-created Symptom Checker will give you the most likely causes and next steps.

Symptoms of Bloody Diarrhea in Dogs

Symptoms of bloody diarrhea in dogs may include:

My Dog Has Bloody Diarrhea. What Should I Do?

If your dog is experiencing bloody diarrhea, don’t try to treat your pup at home. Call your veterinarian or take your dog to an emergency vet hospital.

Most causes of bloody diarrhea in dogs require specific medications, and some are even life-threatening if not treated quickly. Because bloody diarrhea can cause a dog extreme discomfort and lead to severe dehydration, veterinary attention is needed within 24 hours.

Until your dog sees the vet, make sure water is always available and only offer your pup a bland diet. This includes cooked, boneless, skinless chicken breast (plain, no seasoning) with plain white or brown rice

Causes of Bloody Diarrhea in Dogs

Causes of bloody diarrhea in dogs may include:

All dogs—no matter their age, gender, or breed—can develop these causes.

How Veterinarians Diagnose Bloody Diarrhea in Dogs

Veterinarians diagnose bloody diarrhea in dogs by first obtaining a pup’s medical history. Let your veterinarian know any relevant information. Your vet will then perform a thorough exam, which will include gently palpating the abdomen and checking for a rectal mass or anal gland mass.

Your vet may then run the following tests:

  • Fecal float test to check for intestinal parasites. Your vet will request that you bring in a fresh sample of your dog’s stool. 

  • Full blood work to screen for hemorrhagic gastroenteritis, anemia, and low protein levels that may occur with GI disorders

  • Parvo test

  • cPL test: to screen for pancreatitis

  • Abdominal X-rays and/or ultrasound to check for cancer, inflammatory bowel disease, intussusception, foreign body ingestion, and pancreatitis

  • Fecal cytology to test for Clostridium perfringens

  • ACTH stimulation test to screen for Addison’s disease in dogs

  • Fecal culture to test for bacterial infections, such as salmonella and E. coli

  • Endoscopy or colonoscopy to look for gastrointestinal masses and obtain a biopsy if one is present. Your vet will also obtain biopsy samples of the GI tract to screen for inflammatory bowel disease.

  • Cobalamin/folate levels to determine if there’s a vitamin B12 or folate deficiency that can occur with GI disorders

Treatment of Bloody Diarrhea in Dogs

Treatment for bloody diarrhea in dogs depends on the underlying cause as well as the severity of the diarrhea and dehydration.

Treatment options may include:

  • Probiotics—Probiotics like Purina® Pro Plan® Veterinary Diets FortiFlora® or Nutramax® Proviable® can help restore the healthy bacteria in the GI tract.

  • Medications—Medicine may be used, depending on the cause of the bloody diarrhea. These medications may include metronidazole, Albon®, Panacur®, or Drontal™ Plus.

  • Hospitalization—Hospitalization includes 24-hour intensive care, which will be needed for dogs who are critically ill with conditions such as parvovirus, hemorrhagic gastroenteritis, pancreatitis, or Addison’s disease.

  • Intravenous (IV) fluid therapy or subcutaneous fluids (fluids given under the skin)—These methods help with hydration.

  • Referral to an oncologist—If cancer is present, your vet may refer you to a veterinary oncologist. Treatment options may include surgery and/or chemotherapy.

  • Surgery—This may be indicated for treatment of trauma, cancer, pythiosis, foreign body obstruction, intestinal mass, or intussusception.

  • Discontinuing medications—Your vet may recommend stopping any medicine that may be causing bloody diarrhea in your dog, such as steroids or NSAIDs.

Recovery and Management of Bloody Diarrhea in Dogs

Recovery from bloody diarrhea in dogs depends on the cause and severity.

Some dogs recover within 24 hours after being sent home with medications, probiotics, and a bland diet. Others may need to be hospitalized for several days. 

If surgery is needed, recovery may take 10 to 14 days. Certain conditions—such as Addison’s disease and IBD—are not curable and require long-term medications.

During your dog’s recovery, provide your pup any medications, supplements, and diets as directed by your vet.

A recheck appointment should be scheduled with your vet after treatment to make sure your pet is improving. During this visit, your vet will determine if any additional diagnostic tests are needed to manage chronic illnesses, if present.

Some dogs may not improve even with treatment, and humane euthanasia may be recommended.

Prevention of Bloody Diarrhea in Dogs

Preventing bloody diarrhea in dogs includes:

Bloody Diarrhea in Dogs FAQs

Can a stomach bug in dogs cause bloody diarrhea?

A stomach bug may cause inflammation and disrupt the normal bacterial population in a dog’s GI tract. This could lead to bloody diarrhea as well as other symptoms, such as decreased appetite, lethargy, and vomiting.

Why is my dog pooping blood but acting fine?

Sometimes dogs poop blood at the end of a normal bowel movement due to straining. If this happens, continue to monitor your dog’s stools. Call your vet if you continue to see blood.

Michelle Diener, DVM


Michelle Diener, DVM


I live in Raleigh, North Carolina. I obtained by BS degree in Biology at UNC-Chapel Hill in 2000 and my DVM degree at NCSU in 2006. I have...

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health