Hemorrhagic Gastroenteritis (HGE)

Hemorrhagic gastroenteritis is a potentially life-threatening intestinal condition of the otherwise healthy dog which manifests as sudden onset bloody, watery diarrhea. The symptoms are extremely dehydrating, much more than might be expected from the amount of diarrhea, and if it is not promptly treated, the dog can go into shock. Vomiting is often part of the syndrome. There are other gastrointestinal diseases which can cause similar diarrhea and similar dehydration but the syndrome we call "HGE" seems to be unique and not associated with other diseases.

Smaller dog breeds seem to have a predisposition towards HGE though any dog can be affected.
Stress and hyperactivity seem to be predisposing factors.


There are no specific tests for HGE but a test called a packed cell volume (also called “pcv” or “hematocrit”) is very helpful in making the diagnosis. This test can be performed in most veterinary hospitals using a few drops of blood. The percentage of the blood volume made up by red blood cells is measured. A normal packed cell volume for a healthy dog would be 37-55%, meaning 37-55% of the blood volume should be red blood cells (the rest is fluid and white blood cells). When the patient becomes very dehydrated, there is less fluid present in the bloodstream and the percentage of blood fluid drops (and consequently the percentage of red blood cells rises).

A dog with HGE will have a pcv greater than 60%.

The measurement of the pcv also usually includes some sort of measurement of total protein (sometimes called “total solids”). In HGE, the total protein measurement from the blood sample is low.

PCV card

Blood sample in a PCV tube being read against a chart
(original graphic by marvistavet.com)

The very high pcv, low total protein and acute onset bloody watery diarrhea in a previously healthy dog is generally the basis for a diagnosis of HGE.


The actual cause remains unknown. What happens is that the intestinal lining and intestinal blood vessels become permeable to fluid. Fluid and associated proteins leak out of the blood vessels and into the intestine (though the blood cells are too big to leak and stay behind). In this way, fluid is lost into the intestine dehydrating the patient and the pcv rises.

There is some suspicion that a bacterium called Clostridium perfringens may be involved so treatment often includes an antibiotic appropriate for this organism.


The heart of therapy is aggressive fluid replacement. The idea is to get the pcv back to the normal range and keep the patient out of shock. Food is withheld for at least a day and only gradually introduced over several days after the vomiting has resolved. Symptomatic treatment for nausea is typically included as is antibiotic therapy. Several days of hospitalization are commonly required for treatment.

Page posted: 6/17/09
Page last updated: 10/23/2014