What causes HGE?
The exact cause of HGE remains a mystery. Theories range from ingesting non-food items, immune-medicated disease, toxins, pancreatitis or a bacterial infection of the gastrointestinal tract.
What are the symptoms of HGE?
HGE is characterized by a very sudden onset of severe bloody diarrhea, often accompanied by vomiting (mucus and blood), loss of appetite and lethargy. Severe hypovolemia (low blood volume) is one of the characteristics of the disease and severe hemoconcentration (concentrated blood) is considered necessary for diagnosis. The packed cell volume (PCV) or hematocrit (HCT), a measurement of the proportion of red blood cells, is often greater than 60% in dogs with HGE. Most dogs have a normal HCT of 37% to 55%. An elevated HCT in combination with a low or normal total solids (TS) is an important clue that a dog may have HGE. Blood bicarbonate levels, blood pH levels, and serum chemistries also give indicators that HGE may be present. The progression of HGE can be so rapid that hypovolemic shock and death can occur within 24 hours
Even though it is not inflamed, the lining of the intestinal tract becomes very leaky. Fluid, protein, and red blood cells seep out of vessels within the intestinal wall. The body responds with a process known as splenic contraction. The spleen serves as a reservoir for red blood cells. When the body senses that more may be quickly needed, the spleen releases its reserves into circulation.
How is HGE treated?
Intravenous fluid therapy with potassium and electrolyte supplementation provides the foundation of HGE therapy. Subcutaneous fluids (given under the skin) are not usually considered adequate to meet the significant fluid requirements of most dogs with HGE. Most dogs are not fed during the first 24 hours of treatment and are often given antibiotics (such as Ampicillin, Enrofloxacin, or Metronidazole) to combat potential secondary intestinal infection (C. perfringens). Additional therapy for HGE may include gastrointestinal protectants (Sucralfate) and anti-vomiting medications. In severe cases, plasma or colloids may be needed to correct severely low blood protein levels.
If intravenous fluid therapy is not given, the dog’s red blood cell count will continue to elevate because of dehydration. In this situation, the dog is at risk for a potentially fatal clotting disorder called disseminated intravascular coagulation (DIC). Once DIC has begun, it is often irreversible and may result in death. Treated early and aggressively, hemorrhagic gastroenteritis has a good prognosis.