Acute Haemorrhagic Diarrhoea Syndrome (AHDS) is a sudden and severe condition that causes vomiting and bloody diarrhea in dogs. It can develop without warning, even in otherwise healthy pets, and requires immediate veterinary attention. If left untreated, AHDS can become life-threatening, making early diagnosis and treatment crucial.
This article explains what AHDS is, its potential causes, symptoms to watch for, treatment options, and how to help prevent it in your dog.
What is Acute Haemorrhagic Diarrhoea Syndrome (AHDS) in Dogs?
AHDS, previously known as Haemorrhagic Gastroenteritis (HGE), is a severe gastrointestinal disorder that leads to sudden onset vomiting and bloody diarrhea. While it can affect dogs of any breed, age, or size, it is more common in small and toy breed dogs such as Yorkshire Terriers and Miniature Schnauzers.
The exact cause of AHDS can sometimes be unclear, but it’s rapid progression means pet owners must act quickly. If your dog develops symptoms, seek emergency veterinary care immediately. Some patients can progress to develop secondary septicaemia (infection of the blood stream) which can be rapidly fatal if left untreated.
What Causes AHDS in Dogs?
While the precise cause of Acute Haemorrhagic Diarrhoea Syndrome is unknown, several factors may contribute to its development, including:
- Dietary indiscretion: Eating non-food items or unfamiliar foods
- Stress and anxiety: Changes in routine or environment
- Pancreatitis: Inflammation of the pancreas
- Immune system disorders: Overactive immune responses or anaphylaxis
- Toxin exposure: Ingestion of harmful substances
- Infections: Bacterial infections can be associated with AHDS, as well as some viral and parasitic infections
- Rare diseases: Like an Addisonian crisis
Even dogs with no prior health issues can develop AHDS, making it essential for owners to remain vigilant.
Symptoms of AHDS in Dogs
Recognising AHDS early can save your dog’s life. Common symptoms include:
- Sudden, severe vomiting
- Large amounts of bloody diarrhoea (often bright red)
- Dehydration (dry gums, sunken eyes)
- Painful abdomen
- Loss of appetite
- Lethargy or weakness
- Fever can sometimes occurs
When to Call a Vet?
If your dog experiences vomiting and bloody diarrhea, contact your veterinarian immediately. Delayed treatment can lead to serious complications such as severe hypovolaemic shock, septicaemia and/or Disseminated Intravascular Coagulation (DIC), a life-threatening blood clotting disorder.
How is AHDS Diagnosed?
There is no single test to confirm Acute Haemorrhagic Diarrhoea Syndrome, but veterinarians use a combination of:
- Physical examination: Assessing hydration levels, abdominal pain, signs of shock, and presence of bloody diarrhoea
- Blood tests: Checking packed cell volume (PCV), white blood cells, electrolytes and biochemistry
- Fecal testing: Ruling out parasites or infectious diseases
- Imaging (ultrasound or X-rays): Ensuring no obstructions or other underlying issues
Treatment for AHDS in Dogs
Acute Haemorrhagic Diarrhoea Syndrome treatment focuses on aggressive supportive care to stabilise the dog and prevent complications. This may include:
- Intravenous (IV) fluid therapy: To combat shock, dehydration and restore electrolyte balance
- Anti-nausea medication: To reduce nausea, vomiting and help with return of appetite
- Pain relief: To ease abdominal discomfort
- Gastroprotectants: To help protect the gastrointestinal lining
- Probiotics: To help restore the boies natural flora and ease diarrhoea
- Antibiotics (if needed): If a bacterial infection or septicaemia is suspectedSevere cases require advanced management in intensive care and may even need a plasma transfusion or other advanced intervention
Most dogs begin improving within 1-2 days, but hospitalisation for several days may be required in severe cases.
Is Acute Haemorrhagic Diarrhoea Syndrome in Dogs Fatal?
AHDS can be fatal if left untreated due to severe dehydration and shock. However, with prompt veterinary care, most dogs recover well. The key to survival is early intervention—if you notice symptoms, seek emergency care immediately.
Prognosis and Recovery from AHDS
With timely treatment, most dogs make a full recovery. Recovery time varies but typically includes:
- 24 to 48 hours of intensive care
- Gradual reintroduction of food (bland diet recommended)
- Monitoring hydration and energy levels at home
- Avoiding stress and dietary changes to prevent recurrence
Some dogs may be prone to recurring episodes, so it’s important to work with your vet to manage their diet and lifestyle.
Can Acute Haemorrhagic Diarrhoea Syndrome be Prevented?
While AHDS can develop suddenly, there are steps to reduce the risk:
- Maintain a consistent diet: Avoid sudden food changes or unfamiliar treats
- Prevent dietary indiscretion: Keep your dog from eating garbage, non-food items, table scraps, or things found on the ground on walks
- Manage stress: Minimise anxiety and maintain a routine
- Regular vet check-ups: Early detection of gastrointestinal issues can help prevent complications
- Keep toxins out of reach: Ensure household chemicals and foods which toxic to pet are inaccessible
Although prevention isn’t always possible, being proactive about your dog’s health can lower the chances of AHDS.
Prompt Action Can Save Your Dog’s Life
If your dog is experiencing sudden vomiting and bloody diarrhea, seek immediate veterinary care. AHDS can progress rapidly, and early treatment significantly improves recovery chances.
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