Why does my dog eat grass?

Why Dogs Eat Grass

Dogs primarily eat grass due to dietary fiber needs, instinctive behavior, or to induce vomiting when experiencing gastrointestinal discomfort.

Common Reasons for Grass Eating Behavior

1. Dietary Fiber Deficiency

• Dogs may consume grass to supplement their diet with fiber when their regular food lacks sufficient fiber content 1
• In a documented case study, a Miniature Poodle with a 7-year history of plant eating followed by vomiting completely resolved this behavior after switching to a high-fiber diet 1
• The behavior stopped within 3 days of dietary change and remained resolved for over a year

2. Digestive Discomfort

• Dogs may instinctively eat grass to induce vomiting when experiencing gastrointestinal upset
• This self-medicating behavior helps them expel substances causing stomach distress
• Grass contains fiber that can help with digestion and may soothe minor digestive issues

3. Natural Instinctive Behavior

• Wild canids are known to consume plant material as part of their natural diet
• Domestic dogs may retain this instinct despite commercial diets
• Some dogs may simply enjoy the taste or texture of grass

Health Considerations

Potential Risks

• Grass treated with pesticides, herbicides, or fertilizers can be toxic to dogs
• Grass seeds can become lodged in various body parts, particularly:
  • External ear canals (51% of cases) 2
  • Interdigital webs
  • Eyes, nose, and other areas 2
• Certain breeds like Springer Spaniels, Golden Retrievers, and Brittany Spaniels have higher prevalence of grass seed foreign body issues 2
• Seasonal risk is highest between June and September, with July having 176 times higher risk than January 3

When to Be Concerned

• Persistent or excessive grass eating followed by vomiting
• Signs of gastrointestinal distress (lethargy, decreased appetite, diarrhea)
• Visible discomfort during or after eating grass
• Grass eating that begins suddenly in a dog that previously didn't show this behavior

Management Approaches

Dietary Modifications

• Consider switching to a higher-fiber commercial diet 1
• Miscanthus grass fiber has been shown to be well-tolerated in canine diets and can modulate gut microbiota similar to traditional fiber sources 4
• Ensure the dog's regular diet meets all nutritional requirements

Environmental Management

• Limit access to potentially treated grass areas
• Be particularly vigilant during high-risk seasons (summer months) 3
• Consider providing safe, dog-friendly plants or grasses indoors if the behavior seems compulsive

Veterinary Consultation

• Consult a veterinarian if grass eating is excessive or accompanied by:
  • Frequent vomiting
  • Weight loss
  • Changes in appetite
  • Lethargy or other concerning symptoms

Conclusion

Occasional grass eating is typically normal canine behavior and often not a cause for concern. The most compelling evidence suggests that increasing dietary fiber may resolve persistent grass-eating behavior in many dogs 1. If your dog's grass eating seems excessive or is accompanied by other symptoms, veterinary consultation is recommended to rule out underlying health issues.