Why Does My Dog Eat Poop? The Gross Habit, Explained (and Fixed)
The short answer
Poop-eating (coprophagia) is surprisingly common and usually behavioral — instinct, boredom, stress, or learned habit. But it can also point to diet gaps, parasites, or poor absorption, so it’s worth a vet check plus some management to stop it.
Coprophagy is the behaviour owners find hardest to talk about and hardest to fix. It is also more common than most people assume, and the best evidence available says something counterintuitive: in most cases there is nothing medically wrong with the dog at all.
The largest study on this found no underlying pathology
In 2018, Benjamin Hart and colleagues at UC Davis published work in Veterinary Medicine and Science titled 'The paradox of canine conspecific coprophagy'. They ran two large web-based surveys, gathering over 1,500 usable responses in each, comparing dogs that ate stools with dogs that did not and characterising the behaviour in detail.
Roughly 16% of dogs were frequent coprophagics, defined as having been seen eating stools at least six times. The headline finding was negative: the researchers found no reliable association with gastrointestinal disease, nutritional deficiency, or compulsive disorder. Coprophagic dogs were not sicker, not worse fed, and not more anxious than the comparison group.
The one clear behavioural correlate was appetite. Coprophagic dogs were significantly more likely to be described by their owners as greedy eaters. And the behaviour was overwhelmingly directed at fresh stools — specifically, stools no more than about two days old.
The den-hygiene hypothesis
That two-day threshold is the most interesting detail in the paper, because it is not arbitrary. Many common intestinal parasites shed eggs that are not immediately infective; they need a period of development — often around two days — before they become capable of causing infection.
Hart's team proposed that coprophagy is an inherited den-hygiene behaviour from the ancestral wolf: consuming fresh faeces from the resting area removes them before the parasite load in them becomes dangerous. A wolf that cleaned the den promptly protected the pack. The behaviour is protective in origin, which is precisely why it is so hard to train away — you are working against something that was selected for.
It also explains why the behaviour is not a sign of a problem. Your dog is not deficient or disordered. It is running an old subroutine in a context where it is no longer needed and where we find it repellent.
The other causes worth separating out
- Puppyhood. Very common and usually outgrown. Puppies explore orally, and mothers consume their puppies' waste to keep the nest clean, so puppies see it modelled.
- Attention. If eating stools produces a dramatic reaction — shouting, chasing across the garden — some dogs learn it is a reliable way to make something happen.
- Learned avoidance of punishment. Dogs punished for house-training accidents sometimes learn to remove the evidence. This is a training-induced cause and one of the strongest arguments against punishing accidents.
- Other species' faeces. Cat litter, and horse, rabbit or goose droppings, are a separate behaviour from eating dog stools and are largely driven by taste and undigested nutrient content. The Hart study specifically addressed conspecific coprophagy — dog eating dog.
- Genuine medical drivers. Rarer, but real: conditions causing malabsorption or a sharply increased appetite, and some medications, notably steroids.
Why the products mostly do not work
The Hart study also assessed 11 commercial products marketed for coprophagy, along with several behaviour-modification approaches. The results were poor across the board — success rates for the products were low, in the single digits to low double digits.
Nor did the common training approaches fare much better. What did work, unsurprisingly, was management: preventing access to stools in the first place.
Management beats correction here
Pick up immediately — within minutes, not at the end of the day. Keep your dog on a lead in the garden until the habit weakens, and go out with them rather than watching from a window. Teach a strong 'leave it' and a reliable recall, and pay both generously. Move the cat's litter tray behind a baby gate or a cat flap. Prevention is the intervention with the actual evidence behind it.
What not to do
Do not punish it. Punishment after the fact does not connect to the behaviour, and punishment during it teaches the dog to eat faster or to do it out of sight — which is worse. It can also create exactly the evidence-removal behaviour described above.
Do not shout or chase. For an attention-motivated dog this is a reward. Walk over calmly, redirect with something better, and pay for the redirect.
When to involve a vet
See a vet if coprophagy starts suddenly in an adult dog that never did it, if it comes with weight loss, increased appetite, increased thirst, diarrhoea or a poor coat, or if your dog is on medication such as steroids. Also keep parasite prevention current — eating stools raises the risk of picking up worms and protozoal infections such as giardia — and be aware that this is one of the more meaningful routes for transmitting parasites into a household with young children.
Realistic expectations
Most puppies grow out of it. Adult dogs that have done it for years, however, are working from a behaviour with deep evolutionary roots and a strong reinforcement history, and full extinction is uncommon. The realistic goal is reliable management rather than a cure — clean up fast, control access, keep parasite prevention current, and stop treating it as a moral failing on the dog's part. It is not one.
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Frequently asked
Why does my dog eat poop?
The largest study on this — Hart et al., 2018, covering over 3,000 survey responses — found no link to gastrointestinal disease, nutritional deficiency, or compulsive disorder. The leading explanation is an inherited den-hygiene behaviour from wolves: consuming fresh stools before the parasite eggs in them become infective.
Does eating poop mean my dog is missing nutrients?
Usually not. That is a widespread belief the research does not support — coprophagic dogs were not more poorly nourished than non-coprophagic ones. The one clear correlate was being a greedy eater. Sudden onset in an adult dog is worth a vet check.
Do coprophagy deterrent products work?
Largely no. The Hart study evaluated 11 commercial products and found success rates were very low. Management — immediate clean-up and preventing access — was far more effective.
How do I stop my dog eating poop?
Pick up immediately rather than at the end of the day, supervise in the garden instead of watching from indoors, keep your dog on a lead until the habit fades, teach a strong 'leave it' and recall, and block access to the cat's litter tray. Do not punish it — that teaches dogs to eat faster or hide it.
Is it dangerous for my dog to eat poop?
The main risk is parasites and protozoal infections such as giardia, so keep prevention current. It also matters for household hygiene, particularly with young children. Get a vet check if it starts suddenly in an adult dog or comes with weight loss or diarrhoea.
Why does my dog eat cat poop specifically?
That is a different behaviour from eating dog stools. Cat faeces are relatively high in undigested protein and fat because of a cat's diet, which makes them genuinely appealing. The practical fix is physical — a covered tray, a baby gate, or a cat flap the dog cannot use.
Sources
Every claim on this page is checked against published veterinary and animal-behaviour research. Here’s where it comes from.
- 1The paradox of canine conspecific coprophagy — Hart et al., Veterinary Medicine and Science (2018)
- 2The paradox of canine conspecific coprophagy (full text) — PubMed Central
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