It's the behavior owners are most embarrassed to mention at the vet — and one of the most common questions in canine behavior. Coprophagia (eating feces) is genuinely unpleasant to witness, but understanding why it happens is the first step to addressing it.
How Common Is It?
More common than most people realize. A large survey study of dog owners presented at the American Veterinary Society of Animal Behavior found that about 16% of dogs are "serious" stool eaters (observed doing it more than 6 times) and 24% had been observed eating feces at least once. It's not a rare aberration — it's a widespread behavior with real explanations.
The Instinctive Origins
Mother dogs routinely consume the feces of their puppies to keep the den clean and eliminate odors that could attract predators. This is a deeply functional, adaptive behavior. Puppies themselves often eat feces as part of their exploratory oral phase — they're investigating the world, and feces contain information (scent, chemical signals) worth investigating. Most puppies grow out of this naturally between 9 months and 1 year.
One of the more surprising research findings: dogs preferentially eat fresh feces (within 1-2 days old) over older material. This mirrors the behavior of ancestral dogs who would consume the feces of herbivores as a supplemental nutrition source — fresh herbivore feces contain partially digested plant matter, enzymes, and B vitamins. Some researchers believe dogs eating their own or other dogs' feces may be responding to enzyme or probiotic deficiency in their diet.
Common Causes in Adult and Senior Dogs
- Nutritional deficiency: inadequate enzyme activity, vitamin B deficiency, or insufficient caloric intake can drive feces-eating as compensatory nutrition-seeking
- Malabsorption disorders: if food isn't being properly absorbed, feces may still contain nutrients the dog recognizes as worth consuming
- Attention-seeking: if the owner reacts dramatically to the behavior, some dogs learn it produces engagement (even negative attention is attention)
- Anxiety or stress: coprophagia increases in anxious dogs, particularly those with separation anxiety or confined dogs with limited stimulation
- Learned behavior: dogs who see other dogs doing it may learn it; puppies exposed to it early may continue
- Medications: steroids significantly increase appetite and can lower inhibition toward eating unusual substances
How to Address It
First: rule out medical causes with a vet check, especially if it's a new behavior or accompanied by weight loss or digestive issues. Then: ensure prompt cleanup (removing the opportunity is the most effective intervention), review diet quality and consider adding digestive enzymes or probiotics, increase mental and physical enrichment to address boredom and anxiety, and train a reliable "leave it" cue for walks.
Commercial deterrent products that make feces less palatable (added to food) have mixed results — they work for some dogs, not others. The most reliable approach is a combination of opportunity reduction and addressing the underlying driver.
💩 Key Takeaways
- About 16% of dogs are regular feces-eaters — it's far more common than owners realize
- Mother dogs eat puppy feces instinctively — the behavior has ancient adaptive roots
- Dogs prefer fresh feces — possibly responding to nutritional content in ancestral behavior
- Medical causes include malabsorption, enzyme deficiency, and certain medications
- Prompt cleanup + diet review + enrichment addresses most cases effectively