Etiology

Etiological factors for Acute Hemorrhagic Diarrhea Syndrome (AHDS) or hemorrhagic gastroenteritis (HGE) are

• Clostridium perfringens proliferation (abundant in the duodenum of affected dogs)

• Dietary or microbial toxins

• Severe dietary indiscretion

• Clostridial proliferation (unclear if it’s a cause or consequence of the disease)

• Clostridial toxins (not significantly involved in pathogenesis, though newly discovered toxins may play a role)

• Acute enteritis (leads to negative effects on intestinal microbiota)

• Acute dysbiosis (caused by disruption of intestinal microbiota, particularly species diversity)

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Clinical Signs

Clinical signs for Acute Hemorrhagic Diarrhea Syndrome (AHDS) are

• Acute onset bloody diarrhea

• Vomiting

• Anorexia

• Severe dehydration

• Hypovolemic shock (in various stages)

• Lethargy

• Abdominal pain

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Diagnosis

• High Packed Cell Volume (PCV) – Often above 65%.

• Normal or Low Serum Total Solids – Includes low total proteins, albumin, or globulins.

• White Blood Cell Counts – May be normal, high, or low, depending on disease severity.

• Mild Thrombocytopenia – Common in affected dogs.

• Serum Biochemistry Changes:

  • Pre-renal azotemia

  • Increased liver enzymes

  • Hypoglycemia

  • Electrolyte abnormalities

• Metabolic Acidosis – Often present.

• Abdominal Radiographs – Typically show an enteritis pattern with fluid and gas-filled small intestinal loops.

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Differential Diagnosis

• Parvovirus Infection

• Bacterial Infections –

  • Salmonella

  • Campylobacter

  • Clostridium perfringens

  • Clostridium difficile

• Severe Parasitic Infestations

• Dietary Indiscretion

• Intestinal Volvulus or Intussusception

• Acute Necrotizing Pancreatitis

• Acute Liver Disease

• Hypoadrenocorticism

• Sepsis

• Immune-Mediated Thrombocytopenia

• Vitamin K Antagonist Rodenticide Toxicosis

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Treatment

• Aggressive Fluid Therapy:

  • Intravenous Boluses:

    • Isotonic crystalloid solutions (10–20 mL/kg) to treat hypovolemic shock.

    • Synthetic colloids (e.g., hetastarch): 5–10 mL/kg bolus with 10 mL/kg isotonic crystalloid bolus, continued with a constant rate infusion (1 mL/kg/hr).

  • Reassessment: Perfusion and cardiovascular status should be reassessed every 15 minutes. Additional boluses may be given until normal blood pressure is restored.

  • Fluid Deficits: Replace over a 6–12 hour period, accounting for maintenance requirements and ongoing losses from diarrhea.

  • Electrolyte Correction: Correct deficits such as hypokalemia.

• Symptomatic Treatment:

  • Antiemetics/Antinausea Drugs:

    • Maropitant (1 mg/kg IV or SC)

    • Gastric Antacids (if gastric mucosa is compromised):

      • Pantoprazole (1 mg/kg q 12 h IV)

      • Omeprazole (1 mg/kg q 12 h PO)

      • Famotidine (1 mg/kg IV q 12 h) 

• Broad-Spectrum Antibiotics:

  • Indications: Administered intravenously for severe cases with existing or impending sepsis, especially when mucosal sloughing is present.

  • No Antibiotics for Mild to Moderate Cases: A study showed no benefit in mild to moderate cases, as antibiotics didn’t reduce time to resolution or length of hospitalization.

• Fasting:

  • 12–24 Hours: Fasting for 12–24 hours is recommended in affected dogs.

• Refeeding:

  • Offer small quantities of easily digestible food frequently (e.g., boiled chicken and rice, or commercial prescription diets).

• Probiotics:

  • Use of Probiotics: Recommended for long-term management, as they may help modulate intestinal immune function, promote epithelial cell homeostasis, and exert neuromodulatory effects.

  • Preferred Products: Probiotics designed for dogs and cats by reputable manufacturers. Over-the-counter products are less reliable.

  • Strains: Products with single or multiple bacterial strains are suitable.

  • Duration: Administer for 2–4 weeks for acute enteritis.

  • Timing of Probiotic Use: It may be better to delay probiotic use in dogs with bloody diarrhea and compromised intestinal mucosal barrier until hemorrhagic diarrhea resolves.