Dave Zanoni
Why Dogs Eat Poop (and What Science Actually Says)
“Why Does My Dog Eat Poop?” Isn’t Just Gross Curiosity
It’s one of those behaviors that makes even the most patient dog owner cringe — a dog eating poop. But before labeling it disgusting or “bad,” it’s worth understanding what’s actually happening. The act, called coprophagia, isn’t random or purely behavioral. It’s a behavior seen throughout canine evolution and can connect to biology, environment, and sometimes, underlying health issues. Understanding it isn’t about judgment — it’s about insight.
On this page:
1. The Evolutionary Roots of Poop-Eating
Long before modern dog food existed, early canines and wolves lived by instinct. Researchers at the University of California found that wild wolves ate feces in their dens to reduce parasite risk — because parasite eggs take about 48 hours to become infectious. By removing fresh waste, they protected the pack.
Modern dogs still show traces of that instinct. Surveys reveal most dogs who eat feces prefer it less than two days old, aligning perfectly with that ancient behavior. It’s biology — not rebellion.
2. Behavioral and Environmental Factors
Science points strongly to environment and emotion as major influences.
- Boredom and lack of enrichment: Dogs left unstimulated may create their own form of “entertainment.” Repetitive behaviors, including coprophagia, can develop when life feels predictable or empty.
- Anxiety and stress: Shelter dogs and those isolated for long periods show higher rates of feces-eating, suggesting emotional roots rather than digestive ones.
- Attention-seeking: Dogs quickly learn what earns a reaction. Even negative attention — yelling or chasing — can reinforce the behavior.
- House-training confusion: Puppies scolded for accidents sometimes try to “hide the evidence.”
In most cases, coprophagia is less about nutrition and more about unmet emotional or environmental needs.
3. Medical and Nutritional Considerations
That said, biology still matters. Some medical conditions can create or worsen the behavior:
- Exocrine Pancreatic Insufficiency (EPI): reduced enzyme output leads to poor nutrient absorption.
- Parasites or malabsorption disorders: nutrients pass through undigested.
- Endocrine issues: such as diabetes or Cushing’s disease can alter hunger and appetite control.
There’s also the question of nutrition itself. Some dogs may find feces appealing because it still contains undigested fats and proteins, especially if the diet is low in digestibility.
However, large-scale studies haven’t confirmed that a specific nutrient deficiency causes the behavior. A 2018 study published in Veterinary Medicine and Science found no measurable nutrient or digestibility differences between dogs who ate feces and those who didn’t. So while feeding a balanced, highly digestible diet supports better gut health, coprophagia isn’t automatically a “deficiency problem.”
4. The Science of Habit: Why It Persists
Dogs are opportunistic eaters. Once a behavior like this provides any form of satisfaction — whether it’s taste, curiosity, or attention — it can become self-reinforcing. Behavioral scientists call this a “learned maintenance loop.” It’s not easy to break, but it’s possible with consistency, patience, and environment management.
5. Practical, Evidence-Based Steps
You don’t need gimmicks or folklore. Science and structure usually solve it.
What helps:
- Immediate cleanup — most dogs only eat fresh feces.
- Mental enrichment — puzzle feeders, scent work, and play reduce boredom-related habits.
- Behavior redirection — calm “leave it” training works better than scolding.
- Health screening — rule out digestive, enzyme, or metabolic issues.
What rarely helps:
- Pineapple, meat tenderizers, or “bitter” additives — these have no reliable scientific support.
- Punishment — this often makes the behavior worse through anxiety reinforcement.
6. Health Risks of Coprophagia
Though often harmless, it can expose dogs to parasites, bacteria, or medication residues from other animals’ waste. Occasional incidents might not cause problems, but frequent or compulsive feces-eating deserves evaluation. Signs like weight loss, diarrhea, or vomiting should always be discussed with a veterinarian.
7. Understanding Over Judging
When you strip away the human reaction, what remains is a behavior that once made evolutionary sense — but doesn’t fit modern life. Poop-eating doesn’t make a dog “gross” or “broken.” It’s communication. Sometimes it says, I’m bored. Sometimes, I’m anxious. And occasionally, My gut isn’t working right.
The role of the pet guardian is to listen to what the behavior might be saying — and respond with care, not punishment.
Final Thoughts
Coprophagia is unpleasant, but it’s not mysterious. It’s a behavior that sits at the intersection of instinct, environment, and biology — not a reflection of bad manners or failed training. Science gives us the “why.” Empathy gives us the “how.” When we combine both, our dogs get the kind of understanding they deserve.
Veterinary Recommendation: If coprophagia persists despite environmental and behavioral adjustments, consult your veterinarian promptly. Comprehensive fecal panels, increasingly incorporating microbiome analysis, can identify underlying gastrointestinal imbalances or infections. Early intervention ensures optimal health for your dog.
References
- Hart, B.L. (2018). The paradox of canine coprophagy: Evolutionary and behavioral perspectives. Veterinary Medicine and Science.
- Boze, A. et al. (2022). Digestibility and fecal composition in coprophagic dogs compared with controls. Vet Med Sci.