Diarrhea in Dogs & Nutritional Management

Acute vs Chronic Diarrhea in Dogs 

Diarrhea in dogs is a common clinical sign that may present acutely or become chronic, requiring careful evaluation of underlying causes. Understanding whether a case is acute or part of a chronic condition is key to guiding appropriate workup and long-term care.  

Acute diarrhea may resolve itself, but in cases where diarrhea lasts 3 weeks or longer, you may consider it chronic. In chronic presentations, where causes such as parasites, bacterial infections, cancer, and non-GI disease have been excluded, they often fall under the umbrella of canine enteropathy, where therapeutic nutrition plays a key role in diagnosis and treatment. 

Read more about Chronic Enteropathy in Dogs. 

Common Triggers and Underlying Causes 

Common causes of diarrhea include: 

  • Dietary indiscretion 
  • Food intolerance 
  • Parasitic, bacterial, or viral infection 
  • Abrupt change in diet 
  • Stress, triggered by the gut-brain axis 
  • Inflammatory Bowel Disease 

Other factors, which are specifically associated with chronic enteropathy, include genetics, intestinal barrier integrity, gut microbiota, and intestinal immune response. 

 For a deeper understanding of how the microbiome impacts digestive health, visit our page on Managing the Gut Microbiome. 

Localizing and Monitoring Diarrhea 

Managing diarrhea in dogs starts with identifying whether it’s small, large, or mixed bowel in origin, as this guides both diagnostics and treatment. You may consider using the Diarrhea Localization Assessment Tool. 

Learn more about on the page Why Distinguish Between Small and Large Bowel Diarrhea. 

In addition to localizing diarrhea, evaluating stool quality is an essential part of the clinical assessment and monitoring of diarrhea in dogs. The Fecal Scoring Chart can be shared with owners and helps provide a standardized method for scoring stools and identifying diarrhea  with a 7-point scoring system: 

  • Score 1: Very hard, dry, or pellet-like stools that may be difficult to pass 
  • Score 2 (ideal consistency): Firm, but not hard, segmented stools that leave little or no residue when picked up 
  • Score 3–4: Log-shaped stools with little to no segmentation that leave a residue when picked up  
  • Score 5–6: Soft, pile-shaped stools that and leave noticeable residue when picked up 
  • Score 7: Watery, puddle-shaped stools Using this tool consistently allows clinicians to monitor stool changes over time and evaluate response to dietary or therapeutic interventions. 

 

Nutritional Intervention 

 You may find that many dogs respond well to dietary changes and nutritional therapy, eliminating the need for biopsies and histopathology. Some of the key considerations for the nutritional management of diarrhea in dogs include:  

  • Highly digestible diets with a low to moderate fat content in small bowel diarrhea 
  • Soluble and insoluble fiber-rich diets in dogs with large bowel diarrhea 
  • Diet Elimination Trials as a diagnostic tool to help narrow down allergens or intolerances with novel or hydrolyzed proteins 
  •  Probiotic products to manage small, large, and mixed bowel diarrhea