Why Do Dogs Eat Other Dogs' Poop? Coprophagia Causes & Fixes

If you've ever watched your dog gleefully snack on another dog's stool at the park and wondered, "why do dogs eat other dogs' poop?" — you're far from alone. Coprophagia (the clinical term for feces-eating) is one of the most common and most reviled behaviors in pet dogs. A landmark study published in Veterinary Medicine and Science found that roughly 16% of dogs are considered "serious" stool eaters, having been caught in the act more than six times.

The good news? This behavior is usually fixable. But solving it starts with understanding the real reasons behind it — which range from evolutionary holdovers to nutritional gaps to pure behavioral habit. Let's break down the science, the risks, and the proven strategies that actually work.

The Science Behind Why Dogs Eat Other Dogs' Poop

Researchers have identified several overlapping theories for canine coprophagia, and the truth is that multiple factors often combine in a single dog. A widely cited 2018 study by Dr. Benjamin Hart at the UC Davis School of Veterinary Medicine surveyed over 1,500 dog owners and found some surprising patterns that challenge common assumptions.

Evolutionary and Ancestral Drivers

Wolves and wild canids sometimes consume feces — particularly the feces of pack members who are ill or very young. The leading evolutionary theory suggests this behavior served a den-sanitation function: removing feces reduced parasite loads and minimized scent trails that could attract predators. When your dog eats another dog's stool, they may be acting on this deeply ingrained den-cleaning instinct, especially if they perceive the other dog as part of their "pack."

Nutritional Deficiency Theory

One of the oldest explanations is that dogs eat feces because their diet is missing something. While this can be a factor, the UC Davis study found that coprophagic dogs were no more likely to be on low-quality diets than non-coprophagic dogs. However, specific scenarios do support this theory:

• Exocrine Pancreatic Insufficiency (EPI): Dogs with EPI cannot properly digest food, so their stool contains undigested nutrients that still smell and taste like food. This condition requires veterinary diagnosis and lifelong enzyme supplementation.
• Intestinal parasites: Heavy worm burdens can rob a dog of nutrients, creating a deficiency-driven urge to consume feces.
• Underfeeding: Dogs on calorie-restricted diets without adequate fiber may seek additional "food" sources, including stool.
• Vitamin B deficiency: Some evidence links B-vitamin malabsorption to coprophagia, though this is more common in dogs with chronic GI disease.

Behavioral and Psychological Factors

For many dogs, the answer to "why do dogs eat other dogs' poop" is simply: because they've learned it feels rewarding. Key behavioral drivers include:

Behavioral Cause	How It Manifests	Most Common In
Attention-seeking	Dog eats poop, owner chases or yells — dog learns this gets a big reaction	High-energy breeds, dogs with owners who react strongly
Boredom / understimulation	Dog investigates feces out of sheer lack of better options	Working breeds, dogs left alone 8+ hours
Anxiety / stress	Compulsive feces-eating as a displacement behavior	Rescue dogs, dogs with separation anxiety
Learned from mother	Puppies observe dam eating feces during den cleaning and mimic the behavior	Puppies from large litters, early-weaned pups
Punishment avoidance	Dog was punished for indoor accidents → eats feces to "hide evidence"	Dogs trained with aversive housetraining methods

The Taste and Smell Factor

Let's be direct: to a dog's olfactory system, which has roughly 300 million scent receptors compared to our 6 million, feces doesn't smell the way it does to us. Dog food — particularly high-protein kibble — passes through the digestive tract with enough residual scent and flavor compounds that the resulting stool still registers as "food-adjacent" to a dog's nose. This is especially true of stool from dogs fed protein-rich or raw diets.

Health Risks of Dogs Eating Other Dogs' Feces

While eating their own stool (autocoprophagia) carries relatively low risk in a healthy, regularly dewormed dog, consuming another dog's feces introduces significant health hazards. Here's what you need to know.

Parasite Transmission

Feces is the primary transmission route for many common canine parasites. When your dog ingests another dog's stool, they may be ingesting infective parasite eggs or larvae:

• Roundworms (Toxocara canis): Eggs are shed in feces and become infective within 2-4 weeks in the environment. Roundworms are also zoonotic — transmissible to humans, particularly children.
• Hookworms (Ancylostoma caninum): Larvae in feces can penetrate skin or be ingested, causing anemia and GI distress.
• Giardia (Giardia duodenalis): Cysts shed in feces are immediately infective and cause diarrhea, weight loss, and dehydration.
• Whipworms (Trichuris vulpis): Eggs can survive in soil for up to 5 years, making environmental contamination a long-term risk.
• Coccidia (Isospora spp.): Particularly dangerous in puppies and immunocompromised dogs.

Bacterial and Viral Exposure

Other dogs' feces can harbor pathogenic bacteria including Salmonella, E. coli, Campylobacter, and Clostridium perfringens. While parvovirus is primarily spread through direct fecal-oral contact, infected stool in the environment is a major transmission vector — and the virus can survive in soil for months.

Medication Residue Risk

If the other dog is on medication — particularly heartworm preventives like ivermectin, NSAIDs, or antibiotics — trace amounts may be present in their feces. While the dose is typically sub-therapeutic, sensitive breeds (Collies, Australian Shepherds, and other herding breeds with the MDR1 gene mutation) could potentially react to ivermectin residue.

Which Dogs Are Most Likely to Eat Other Dogs' Poop?

The UC Davis study and subsequent research have identified several patterns that make certain dogs more prone to coprophagia:

Risk Factor	Details
Greedy eaters	Dogs described by owners as "thieves" or "always hungry" were significantly more likely to be coprophagic
Multi-dog households	More dogs = more available feces = more opportunity to develop the habit
Age	Puppies under 12 months are most likely to experiment; many outgrow it, but some develop a lasting habit
Breed tendencies	Shetland Sheepdogs, Labrador Retrievers, and Border Collies show higher reported rates; Terriers and Poodles show lower rates
Spay/neuter status	Neutered/spayed dogs showed slightly higher rates in some studies — possibly linked to metabolic changes affecting appetite

How to Stop Your Dog From Eating Other Dogs' Poop

Because coprophagia usually has multiple contributing factors, the most effective approach is multi-pronged. Here's a step-by-step framework I've seen work consistently when owners commit to all three pillars simultaneously.

Pillar 1: Veterinary Assessment

Before trying behavioral fixes, rule out medical causes. Ask your veterinarian for:

1. Comprehensive fecal exam: A fecal flotation and Giardia antigen test to check for parasites. Cost: typically $35-$65 at a general practice.
2. Bloodwork panel: A CBC and chemistry panel to check for malabsorption issues, EPI, or metabolic conditions. Cost: $80-$200 depending on your region.
3. Diet assessment: Your vet can evaluate whether your dog's current food meets AAFCO complete-and-balanced standards for their life stage and whether a diet change is warranted.

Pillar 2: Dietary Adjustments

Nutritional strategies that can reduce the drive to eat feces:

• Increase dietary fiber: Adding 1-2 tablespoons of canned pumpkin (plain, not pie filling) per 25 lb of body weight to meals can increase satiety and make the dog's own stool less palatable. Fiber also firms stool, making it easier to pick up quickly.
• Feed multiple smaller meals: Splitting daily food into 3 meals instead of 1-2 reduces hunger-driven scavenging behavior.
• Consider a stool-deterrent supplement: Products containing digestive enzymes and probiotics (such as NaturVet Coprophagia Deterrent or Nutramax Cosequin with added digestive support) may help. These work by improving nutrient absorption so stool contains fewer residual nutrients. Expect to pay $15-$30 for a 60-day supply.
• Switch to a higher-digestibility food: Foods with higher digestibility leave less undigested material in stool. Look for brands with feeding trials (not just formulation) meeting AAFCO standards.

Pillar 3: Behavioral Modification

This is where most owners see the biggest impact. Use only positive reinforcement and force-free methods — punishment-based approaches (yelling, rubbing nose in feces, shock collars) can actually worsen coprophagia by increasing anxiety or teaching the dog to eat feces faster before you can intervene.

Step 1: Environmental management. Pick up your own dog's feces immediately. On walks, keep your dog on a 4-6 foot leash in areas where other dogs defecate. Use a basket muzzle (such as the Baskerville Ultra or Jafco Muzzle) during high-risk outings like dog park visits while training is in progress. A basket muzzle allows panting and drinking but prevents ingestion.

Step 2: Teach "Leave It" reliably. This cue is your primary defense. Train it in low-distraction environments first using high-value treats (freeze-dried liver, chicken) that are always more rewarding than stool. Expect 4-6 weeks of consistent daily practice before the cue is reliable in high-distraction outdoor settings. Working with a certified professional dog trainer (CPDT-KA or IAABC certified) costs roughly $75-$150 per session and can accelerate progress significantly.

Step 3: Teach an incompatible behavior. Train your dog to come to you and sit immediately after they defecate (for their own stool) or when they notice another dog's stool. Reward generously — 3-5 high-value treats in sequence. This creates a new behavioral pathway: "poop on ground → run to human → get amazing treats."

Step 4: Increase enrichment. Boredom-driven coprophagia responds well to increased mental stimulation. Provide puzzle feeders (Kong Classic, Outward Hound Nina Ottosson puzzles), daily sniffari walks, and 15-20 minutes of nosework training. A mentally tired dog is less likely to seek stimulation through feces investigation.

Common Myths About Coprophagia Debunked

There's a lot of bad advice circulating about why dogs eat other dogs' poop and how to stop it. Let's address the most persistent myths:

When Coprophagia Signals a Deeper Problem

While most coprophagia is behavioral, certain presentations warrant urgent veterinary attention. Consult your veterinarian promptly if:

• Your adult dog suddenly begins eating feces after years of not doing so (new-onset coprophagia in dogs over 3 years old can signal GI disease, cognitive decline, or metabolic disorders)
• Your dog is eating feces AND losing weight despite normal or increased appetite (classic sign of malabsorption or EPI)
• Stool is consistently loose, greasy, or foul-smelling beyond normal (indicates digestive dysfunction)
• Your dog is eating non-feces items too — rocks, dirt, fabric (this is pica, a separate condition that may indicate mineral deficiency, anemia, or neurological issues)
• The behavior is compulsive — your dog seems unable to stop even when interrupted and shows signs of distress if prevented

For any case of suspected poisoning or ingestion of a toxic substance alongside feces, contact the ASPCA Animal Poison Control Center at (888) 426-4435 (available 24/7, consultation fee applies) or the Pet Poison Helpline at (855) 764-7661.

Prevention Checklist for Multi-Dog Households

If you have multiple dogs and one is eating the others' stool, this management protocol can break the cycle:

Action	Frequency	Why It Matters
Pick up all feces immediately	After every bowel movement	Removes the opportunity entirely — the single most effective intervention
Feed dogs separately	Every meal	Reduces competition-driven rapid eating and post-meal scavenging
Leash-walk the coprophagic dog	Every outdoor outing	Allows immediate redirection away from other dogs' stool
Quarterly fecal exams	Every 3 months	Catches parasite transmission early; standard is 1-2x/year for non-coprophagic dogs
Heartworm + intestinal parasite preventive	Monthly, year-round	Products like Heartgard Plus or Interceptor Plus cover roundworms, hookworms, and whipworms
Daily enrichment activities	Minimum 30 minutes/day	Reduces boredom-driven coprophagia; puzzle feeders, sniffari walks, training sessions

Frequently Asked Questions

Is it normal for puppies to eat other dogs' poop?

Yes, puppy coprophagia is extremely common. Puppies explore the world with their mouths, and stool investigation is part of normal developmental behavior. Most puppies outgrow this by 9-12 months of age if it isn't inadvertently reinforced (by owner overreaction) and if the environment is managed to limit access. However, if the behavior persists past 12 months, begin active training intervention.

Can my dog get sick from eating another dog's feces?

Absolutely. The primary risks are intestinal parasites (roundworms, hookworms, giardia, whipworms), bacterial infections (salmonella, E. coli), and parvovirus exposure in unvaccinated or under-vaccinated dogs. This is why regular fecal testing — every 3 months for known coprophagic dogs — and consistent parasite prevention are essential. Always consult your veterinarian about an appropriate testing and prevention schedule.

Do commercial coprophagia deterrents actually work?

Results are mixed. These supplements typically contain digestive enzymes, probiotics, or ingredients like Yucca schidigera that alter stool odor and taste. A 2021 review of owner-reported outcomes found roughly 50-60% of dogs showed some reduction in coprophagia with consistent use over 4-6 weeks. They work best as one component of a broader management and training plan, not as a standalone fix. Expect to invest $15-$30 per month for a quality product.

Should I use a muzzle to stop my dog from eating poop?

A basket muzzle is a safe and effective management tool during training, not a permanent solution. Choose a well-fitted basket-style muzzle (Baskerville Ultra, $18-$25, or Jafco Clear Vinyl, $12-$18) that allows your dog to pant, drink, and take treats through the openings. Use it during high-risk outings while simultaneously training a reliable "leave it" cue. Never use a muzzle as punishment or leave it on an unsupervised dog.

Does feeding a raw diet cause coprophagia?

There's no conclusive evidence that raw diets cause coprophagia. However, raw-fed dogs produce stool that is often firmer, smaller, and — because of the high protein content — may retain more food-like scent. Some owners report their raw-fed dogs show less interest in stool (because the stool volume and odor are reduced), while others report no change. If you feed raw, ensure the diet meets FDA safe handling guidelines to reduce bacterial risks for both you and your dog.

How long does it take to stop coprophagia with training?

With consistent daily management and positive reinforcement training, most owners see significant improvement within 4-8 weeks. Complete reliability — where the dog chooses to avoid stool even off-leash — typically takes 3-6 months. Dogs with a long-established habit (years of coprophagia) or underlying anxiety may require longer and may benefit from working with a veterinary behaviorist (DACVB) or a certified applied animal behaviorist (CAAB).