Many conditions result in hemorrhagic diarrhea, although the hemorrhagic gastroenteritis (HGE) syndrome of dogs appears to have unique clinical features that distinguish it as an entity separate from other causes. Although HGE can affect any breed of dog, it is seen most commonly in small breeds.

HGE is considered a common clinical condition, especially in dogs that live in urban settings. There is no way to prevent the syndrome, as we do not know with certainty what causes it. Most affected animals have been previously healthy, have no concurrent illness, and receive the best of care. Clinical findings are variable in both the course and severity of the disease.

The most common sign seen is an acute onset of bloody, often projectile diarrhea. The bloody stools have been likened to dark raspberry jam. The prognosis for patients with HGE is generally excellent if caught early and treated aggressively. Most often hospitalization with intensive fluid therapy and support is necessary.

There are many other diseases/disorders that can appear similar to HGE. These include:

Parvovirus is a contagious virus that can affect any age or breed of dog, although it is most common in the young, unvaccinated pup. The most common signs associated with parvo are vomiting, diarrhea (often with blood), and loss of appetite.

Bacterial enteritis, which is inflammation/infection of the intestinal tract with salmonella, clostridia, is commonly associated with signs that may mimic HGE.

Conditions resulting in endotoxic or hypovolemic shock, often associated with the movement of certain bacteria or toxins, or other overwhelming systemic infections, need to be ruled out.

Intestinal obstruction or intussusception, which is the telescoping of one part of the bowel into another, secondary to foreign bodies, tumors, or parasites can cause similar gastrointestinal signs.

Hypoadrenocorticism (Addison's disease) is an endocrine disorder in which there is a hormonal deficiency, most often corticosteroids and mineralocorticoids, due to a problem with the adrenal glands. These individuals often present with signs extremely similar to HGE.

Uremia is when toxins or poisons are not excreted from the body associated with kidney failure. It is not uncommon for these patients to present with gastrointestinal ulceration, vomiting, and bloody diarrhea.

Pancreatitis, an inflammation of the pancreas, often presents for some combination of vomiting, inappetence, and/or bloody diarrhea.

Coagulopathies, or bleeding disorders, including thrombocytopenia (decreased platelets), warfarin ingestion, disseminated vascular coagulation (DIC), and bleeding secondary to liver disorders may present with bloody diarrhea.

Toxins including arsenic, thallium, Amanita mushrooms, and certain household cleaning products cause bloody diarrhea.