Hematochezia (Blood in Stool) in Dogs

Hematochezia is the presence of bright red, fresh blood in the feces. Hematochezia usually occurs with bleeding in the lower intestines (colon, rectum). Hematochezia should not be confused with melena , which is the passage of dark, tarry, black feces. Melena represents the passage of old, digested blood that has occurred with bleeding higher up in the intestinal tract.

The presence of hematochezia may be a symptom of either a minor problem, or a potentially more serious problem in the animal. One occurrence of hematochezia may be a minor and transient event. Repeated or persistent hematochezia is more serious and should not be ignored. There are several possible causes. The most common cause in older pets is cancer and in younger pets are parasites. General causes include: 

General Causes

Infectious agents, such as bacteria, protozoa, viruses, and intestinal parasites

Dietary intolerance/allergy/indiscretion

Cancer (neoplasia) of the lower bowel

Polyps (benign masses) in the colon or rectum

Inflammatory bowel diseases, such as colitis

Trauma to the lower bowel or anal area

Clotting disorders (coagulopathy)

Intussusception (the telescoping of one part of the bowel into another)

Miscellaneous diseases of the anus, rectum and colon

What to Watch For

Bright red blood in the feces

Possible straining to defecate

Increased number of bowel movements produced

Possibly no other clinical signs

Possibly other systemic signs of illness, such as excessive drinking, urinating, vomiting and diarrhea, lethargy, poor appetite, weight loss

Diagnostic Tests

Rectal examination

Complete blood count (CBC)

Biochemical profile

Urinalysis 

Fecal examination

Coagulation profile

Abdominal X-rays (radiographs) 

Abdominal ultrasound

Colonoscopy

Treatment

There are several things your veterinarian might prescribe to treat your pet' symptoms. These include:

Changes in the animal's diet

Fluid therapy

Deworming medications for intestinal parasites

Antibiotics for bacterial infections

Motility modifying drugs that change the rate of movement of food through the intestines

Intestinal protectant/adsorbent drugs to coat, protect, and sooth the gastrointestinal tract

Home Care

At home administer any prescribed medications as directed by your veterinarian and follow any dietary recommendations closely.

You should also observe your pet's general activity and appetite, and watch closely for the presence of blood in the stool, or a worsening of signs. If any changes occur, notify your veterinarian.