Acute Haemorrhagic Diarrhoea Syndrome (AHDS)
Information for Owners
The exact cause of AHDS in dogs isn’t fully known. What we do know is that something—such as bacteria, viruses, parasites, or a toxin—damages the lining of the gut. When these cells are injured or die, the gut becomes inflamed and the normal balance of gut bacteria is disrupted. This allows harmful bacteria to multiply and cause further damage. As a result, dogs can develop sudden vomiting, diarrhoea, loss of appetite, and low energy. In severe cases, bacteria can move from the gut into the bloodstream, which can lead to a serious infection called sepsis.
Diagnostic Testing
The following tests may be recommended depending on each patient’s condition:
- Bloodwork – assessing blood cells, electrolytes, vitamins and organ function
- Abdominal imaging (ultrasound, radiographs or CT scan)
- Faecal testing
Treatment
Treatment can include intravenous fluid therapy, anti-nausea and prokinetic medication, electrolyte and glucose supplementation and probiotics.
Antibiotics and blood products (such as fresh frozen plasma) may be required in severe cases.
Faecal management systems can be placed to reduce the risk of diarrhoea scalding and allow assessment of fluid losses from the diarrhoea.
A feeding tube may be placed to ensure adequate nutrition, which supports faster recovery of the gut.
Prognosis
Uncomplicated cases typically remain in hospital for 2-3 days for supportive care. In more severe cases, your dog may require hospitalisation for up to a week or more.
Although many dogs recover fully, some may go on to have ongoing or recurring digestive issues. If a dog continues to show chronic gastrointestinal signs, further testing is recommended to look for an underlying cause. This may include faecal testing, diet trials, abdominal ultrasound, blood tests, pancreatic tests, or endoscopy.
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