Haemorrhagic diarrhoea syndrome in canine patients


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haemorrhagic diarrhoea syndrome in canine patients
Matilda in the veterinary hospital soon after presentation. 

Subedited by Dr Phil Tucak

AHDS is a condition that has been recognised in veterinary medicine but remains a diagnostic and therapeutic challenge. It typically presents with acute vomiting, diarrhoea, and often, severe haemorrhage. The pathogenesis of AHDS is multifactorial includin—but not limited to—multiple possible infectious agents, dietary components, trauma and stress. These complexities associated with AHDS hinder the accurate identification of inciting causes and the implementation of targeted therapies.

Some studies have suggested that certain bacterial pathogens, such as Clostridium perfringens and Clostridioides difficile, may play a role in the development of AHDS1. These bacteria can produce toxins that damage the intestinal lining, leading to haemorrhage and diarrhea. Diagnostic workup often includes blood tests, faecal examinations, abdominal imaging (ultrasound or radiography), and occasionally endoscopy or biopsy to evaluate the gastrointestinal tract for lesions and inflammation2

The treatment of AHDS typically involves aggressive supportive care, including intravenous fluids to correct dehydration and maintain blood pressure, anti-emetics to control vomiting, and antibiotics to target potential bacterial pathogens3. The prognosis for dogs with AHDS depends on the severity of the disease and the timely initiation of treatment.

Matilda’s road to recovery 

Matilda’s ordeal began with acute vomiting, inappetence, and diarrhoea over a 24-hour period. Initially, her owner opted for outpatient treatment, but Matilda’s condition deteriorated rapidly within the next 18 hours, and Matilda returned to the veterinary clinic in a state of septic shock, exhibiting obtundation, weak pulses, and signs of collapse. She was also passing copious watery bloody diarrhoea.

Recognising the gravity of the situation, immediate resuscitation efforts were initiated. An intravenous catheter was placed, and oxygen supplementation was provided. Intravenous fluids were administered in boluses at a rate of 10ml/kg, with a total of 50ml/kg provided. Unfortunately, Matilda’s condition showed evidence of continued hypotension, necessitating the initiation of vasopressors in the form of a noradrenaline continuous rate infusion (CRI).

Matilda’s bloodwork revealed several critical abnormalities. She exhibited signs of haemoconcentration and dehydration, marked hyperlactatemia, hypocalcaemia, and hypoglycaemia. Hematologic derangements were also evident, with leukopenia and neutropenia pointing towards severe systemic infection. Elevated liver and renal values indicated the likelihood of multiple organ dysfunction, while a mildly prolonged coagulation profile (PT/APTT) suggested potential coagulation abnormalities.

Treatment approach

Immediate therapeutic measures included the initiation of triple antibiotics comprising metronidazole, amoxicillin/clavulanic acid, and enrofloxacin, to provide comprehensive antibacterial coverage against the infection in the body. To correct her hypoglycaemia, Matilda was placed on a 2.5% glucose solution in lactated Ringer’s solution after receiving diluted glucose boluses.

Matilda remained in intensive care with vigilant monitoring. Hourly assessments encompassed blood glucose, lactate values, blood pressure, temperature, and repeat blood gases to evaluate calcium levels. A comprehensive ultrasound revealed significant ileus, gastroenteritis, and mild pancreatitis, providing further insights into the complexity of her condition.

Matilda’s recovery spanned a week during which she demonstrated gradual improvement. Repeat blood tests showed the normalisation of her renal values, and her blood pressure, blood glucose, and lactate values remained stable. Although she was still weak and unable to ambulate independently, her demeanour improved. Toward the end of her hospitalisation, Matilda also started to eat small amounts of food. Physiotherapy was initiated to aid her in regaining strength.

haemorrhagic diarrhoea syndrome in canine patients
Images 2 & 3 – Examples of the copious watery bloody diarrhoea. Images 4 & 5 – Matilda during her time at AEC Woolloongabba receiving in-hospital veterinary treatment

Potential long-term effects

It is thought that Matilda may experience permanent damage to the fine control of her movements due to her critical illness episode. However, her overall improvement and resilience offer hope for her future.

Following her discharge, Matilda continued to make great strides in her recovery. She has since regained some strength in ambulation and gradually rekindled her zest for life, reminiscent of her pre-septic episode days. Her journey underscores the challenges and triumphs associated with AHDS, emphasising the importance of early diagnosis, aggressive treatment, and the unwavering dedication of veterinary professionals.

Acute haemorrhagic diarrhoea syndrome (AHDS) is a complex and life-threatening condition in dogs characterised by severe gastrointestinal symptoms that can lead to shock and multi-organ dysfunction. This clinical case study explores the challenging journey of Matilda, a 12-year-old female spayed Australian silky terrier, and highlights the dramatic clinical presentation commonly associated with AHDS. Her recovery exemplifies the complexities of this syndrome and the essential role of timely and comprehensive veterinary care.


1. Marks, S. L. (2019). Hemorrhagic Gastroenteritis Syndrome in Dogs. Veterinary Clinics of North America: Small Animal Practice, 49(5), 803-812. doi:10.1016/j.cvsm.2019.04.007.

2. Barrs, V. R., Beatty, J. A., & Tisdall, P. L. (2018). Update on Hemorrhagic Gastroenteritis in Dogs. Veterinary Clinics of North America: Small Animal Practice, 48(5), 839-857. doi:10.1016/j.cvsm.2018.04.006.

3. Leib, M. S., Duncan, R. B., & Noble, S. J. (2020). Hemorrhagic Diarrhea Syndrome in Dogs. Veterinary Clinics of North America: Small Animal Practice, 50(5), 943-958. doi:10.1016/j.cvsm.2020.03.008.

Dr Diana Chua BVSc (Hons) BA/Dip Ed

haemorrhagic diarrhoea syndrome in canine patients

Veterinary Director 

Animal Emergency Centre (AEC) Woolloongabba

Dr Diana Chua is the veterinary director at Animal Emergency Centre Woolloongabba. 

After graduating with honours from the University of Queensland, Dr Chua worked in a general practice clinic for two years before spending the next eight years pursuing her passion in veterinary emergency medicine. 

Dr Chua is currently completing her Master of Philosophy at the University of Queensland with a focus on animal welfare. She strongly believes in working in close partnership with owners in making a difference in their pets’ health and wellbeing; every piece of the whole picture matters

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