Blood in Dog’s Stool (Hematochezia)


Your veterinarian may recommend additional tests, based on results of the above tests and the clinical signs exhibited by the animal. These ancillary tests are selected on a case-by-case basis:

  • An abdominal ultrasound evaluates the size, shape and texture of abdominal organs and helps to determine the presence of tumors. Organs, lymph nodes, and masses can be sampled with a needle or biopsy instrument with the guidance of ultrasound. This test may require referral of your pet to a specialist in veterinary internal medicine or veterinary radiology to perform the procedure.
  • Bacterial fecal cultures may be recommended in those cases where a bacterial cause is suspected.
  • Colonoscopy (lower GI endoscopy) may be of benefit in the patient with hematochezia. Colonoscopy involves the passage of a viewing scope into the lower bowel to visualize the lining of the colon and to allow biopsy of any abnormal tissue. Colonoscopy is performed under general anesthesia, and may require referral of your pet to a specialist in veterinary internal medicine to perform the procedure.


Therapy In-depth for Bloody Stool

Supportive Care

Treatment of the symptoms may be necessary while diagnostic testing is underway, especially if the animal is severely ill or blood loss is dramatic. The following supportive measures may be instituted as needed to reduce the severity of symptoms or stabilize the animal.

  • Intravenous fluid and electrolyte therapy may be indicated in severe cases of hematochezia, especially if there are concurrent systemic signs of illness like vomiting, dehydration or lack of appetite.
  • Treatment for shock may be undertaken in weak or collapsed animals.
  • Food and water may be withheld for 24 hours or more.
  • Antibiotics may be started via injection.

    Symptomatic Care

    With mild cases or nonspecific cases of hematochezia, symptomatic therapy may be tried. Such therapy is aimed at reducing inflammation within the lower bowel and decreasing exposure to materials that are difficult to digest or pass in the stools. Symptomatic treatments are not a replacement for specific therapy. With any serious or persistent hematochezia, it is important to perform diagnostic tests that allow a specific cause to be identified, and then specific therapy is instituted. Examples of symptomatic measures include the following:

  • Changes in diet may be recommended, and may include a trial of either a high fiber diet or a hypoallergenic diet.
  • Thoroughly deworming the pet is often recommended, regardless of whether the fecal examination confirms parasitism. In some cases intestinal parasites are present, but they are difficult to detect on routine fecal screenings. A broad spectrum dewormer such as fenbendazole may be recommended.
  • Antibiotic therapy with oral Flagyl® (metronidazole), tylosin, or tetracycline may be recommended because these drugs alter the bacterial counts in the lower bowel and may have some mild anti-inflammatory properties.
  • Gastrointestinal protectants may be tried, such as the bismuth containing over-the-counter products.
  • Motility modifying drugs that change the rate of movement of food through the intestines may be helpful in some cases.

    Specific Treatments

    Once a diagnosis is made, then specific therapy may be instituted. Specific treatments are sometimes combined with supportive and symptomatic treatments to ensure the hematochezia resolves. Depending upon the cause, the following may be considered:

  • Common treatments used for colitis include dietary changes and oral antibiotic or antibacterial (e.g. sulfasalazine) medications.
  • Corticosteroids may be indicated in some forms of immune-related colitis.
  • Treatments for clotting disorders may include Vitamin K therapy, transfusions of either blood or plasma, and corticosteroids for certain platelet problems.
  • Masses of the colon or rectum are surgically removed whenever possible.
  • Intussusceptions often require correction via require abdominal surgery.
  • Hemorrhagic gastroenteritis usually responds to intensive intravenous fluid therapy and antibiotics.
  • The presence of colonic foreign bodies, such as bones, metallic materials, etc., may sometimes necessitate cleansing enemas or manual removal with the animal under general anesthesia.
  • A variety of treatments exist for perianal fistulas, strictures, and anal sac disease.


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