Dog eating poop: what 1,441 owners reported
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
Watching your dog eat faeces is unsettling, and pet shops sell supplements meant to put an end to it. A survey published in 2018 by Hart, Hart, Thigpen, Tran and Bain in Veterinary Medicine and Science measured both how widespread the behaviour is and how well those solutions are reported to work (see the study, doi 10.1002/vms3.92). Our other guidance is gathered in the dog food section.
Contents · 6 sections
The protocol: two owner surveys, not direct observation
The researchers ran two online questionnaires with owners: the first collected 1,552 responses, the second 1,475, with targeted recruitment of owners of stool-eating dogs. No intervention, no controlled trial: everything rests on what owners report having seen, with the recall bias that implies.
A minority behaviour, but a very targeted one
Among the 1,441 usable respondents of the first survey, 76.9% had never seen their dog eat stools. Frequent coprophagy — defined as at least six observed episodes — concerns 16% of dogs. The most telling result is the age of the stools: 82% of stool-eating dogs in the first survey, and 85% in the second, eat stools that are two days old or less.
The authors read this as a den-cleanliness behaviour inherited from the wolf, fresh stools not yet being infective. It is a hypothesis consistent with their data, but it has never been tested experimentally: nothing demonstrates it to date.
What does not explain the behaviour
The survey finds no association with diet type (82.3% kibble among stool eaters against 78.3% among the others), age, sex, neutering, ease of house-training or compulsive behaviours. In other words, the explanations most often put forward — nutritional deficiency, pathological boredom — do not stand out. Only two factors emerge: dogs described as greedy eaters are overrepresented (51.1% against 28.2%, p < 0.0001), and living in a multi-dog household raises the odds (p = 0.0005). These are cross-sectional associations, with no established direction of causation.
The products sold to stop it: 0 to 2% reported success
This is the study's most useful figure. Eleven North American commercial products were rated by the owners who had tried them: their reported success rate ranges from 0 to 2%. Behavioural methods do barely better, between 1 and 4%: chasing the dog off, rewarding a cue, sprinkling pepper on stools, using a collar. These figures are retrospective and have no placebo group — so one cannot write that these products do not work, but none exceeded 2% success in this series.
Is it dangerous?
A study published in 2026 by Pilla and colleagues in Animals compared the faecal microbiota of 23 stool-eating dogs and 21 non-stool-eating dogs, all clinically healthy (see the study). No difference in dysbiosis index or in bacterial and viral carriage after correction for multiple testing. This is an observational study on 44 healthy dogs with uncontrolled diets, and above all no parasite was screened for: it cannot support the conclusion that coprophagy is risk-free, only that no microbiota alteration was measured. Parasite control therefore keeps its full value, as detailed in our article on how often to deworm a dog.
Frequently asked questions
Should a stool-eating dog's diet be changed?
The survey finds no link between diet type and the behaviour. A dietary change may be justified for other reasons, but it has no documented basis here.
Can the behaviour signal a health problem?
Coprophagy that appears abruptly in an adult dog that never did it warrants veterinary advice, like any change in feeding behaviour — much like the dog that suddenly starts eating grass, a topic covered in our article on why dogs eat grass.
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This guide is part of Planète Pets’s Dogs universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.