What is acute hemorrhagic diarrhea syndrome?
Acute hemorrhagic diarrhea syndrome (AHDS), formerly known as hemorrhagic gastroenteritis (HGE), is an acute (sudden) disorder of dogs characterized by vomiting and bloody diarrhea (“raspberry jam” diarrhea). Most cases occur without warning in otherwise healthy dogs. AHDS can affect any breed, age, size, or gender, but it is most common in small and toy breed dogs such as the Yorkshire terrier, Cavalier King Charles spaniel, and the Maltese.
What causes AHDS?
AHDS is believed to be caused by Clostridium perfringens, a bacterium that is part of the part of the normal gut (GI) flora. These bacteria can produce several toxins and enzymes that can damage the intestinal lining and the underlying blood vessels. This damage causes fluid loss and bleeding into the intestines.
What are the signs of AHDS?
Signs of AHDS may include:
- Vomiting, decreased appetite
- Bloody diarrhea, painful abdomen
- Lethargy sometimes progressing to collapse
- Fever
- High heart rate
How is AHDS diagnosed?
It can be challenging to diagnose AHDS because there are so many possible causes of bloody diarrhea. Evaluation usually requires:
- A complete blood count (CBC) and biochemical analysis of the blood
- Urinalysis
- Radiographs (X-rays)
- Coagulation tests
- Fecal evaluation
- Ultrasound or endoscopic examination of the gastrointestinal tract
The packed cell volume (PCV) or hematocrit (HCT) — a measurement of the proportion of red blood cells in the blood — is often greater than 60% in dogs with AHDS. Most dogs have a normal HCT of 37% to 55%. An elevated HCT in combination with a low or normal total protein is an important clue that a dog may have AHDS. Blood bicarbonate levels, blood pH levels, and serum chemistries also can indicate that AHDS may be present.
How is AHDS treated?
Dogs with AHDS appear severely ill and, if left untreated, may die. In most cases, the disorder appears to run its course in a few days if the dog is given appropriate supportive care.
- Intravenous fluid therapy with potassium and electrolyte supplementation is the basis of AHDS therapy. Subcutaneous fluids (fluids given under the skin) are not usually adequate to meet the significant fluid requirements of most dogs with AHDS.
- Antibiotics may be given to combat potential secondary intestinal infection, although they are no longer routinely used for this condition.
- Additional therapy may include gastrointestinal protectants, such as sucralfate (Carafate®, Sulcrate®), and anti-vomiting medications, such as maropitant (Cerenia®).
- In severe cases, plasma (the liquid portion of blood) or colloids (high protein intravenous fluid) may be needed to correct severely low blood protein levels.
- Probiotics and pain medications are also sometimes used in treating this condition.
If intravenous fluid therapy is not given, the dog’s red blood cell count will continue to increase 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.
