Why Do Dogs Eat Poo? 7 Reasons and How to Stop It

Why do dogs eat poo? In most cases it is a normal, inherited scavenging behaviour, not a sign of hunger or a missing nutrient: the largest study on the subject, from the UC Davis School of Veterinary Medicine, found that 16–23% of pet dogs do it and that the habit was not linked to diet or age. A dog that suddenly starts eating stool as an adult, especially with weight loss, a ravenous appetite or loose stools, should see a vet, because malabsorption, parasites, appetite-boosting drugs and hormonal disease can all trigger it. For everyone else, the fix is management: same-day pick-up, a lead and a solid "leave it". Alongside that, a daily gut routine such as Pure Majesty Pets Liquid Probiotic for Dogs can support stool consistency, though it will not stop the habit.

One thing to know up front: in the same UC Davis survey, 11 marketed anti-poo-eating products had owner-reported success rates of 0% to 2% (Hart et al., 2018). No supplement, including ours, has been shown to stop the behaviour. What follows is what the evidence does support.

Why do dogs eat poo? The 7 reasons that actually hold up

Veterinary behaviourists split the causes into normal behaviour, learned behaviour and medical triggers. Board-certified behaviourists at the US-based VCA Animal Hospitals say medical problems "must first be ruled out before a purely behavioral diagnosis can be made." This table sorts the explanations by how well they are supported.

What the UC Davis research found

Hart and colleagues ran two online surveys: a general behaviour survey with 1,552 usable responses, in which the stool-eating questions were hidden among unrelated items, and a second survey of 1,475 owners whose dogs ate stools frequently (Veterinary Medicine and Science, 2018). In the general survey, 16% of owners had seen their dog eat stools at least six times, and about 23% at least once. The authors' summary is blunt: "No evidence was found relating the coprophagy to diet or the dog's age."

Puppies explore with their mouths, but the habitual stool-eaters in this dataset were overwhelmingly adults. If your adult dog has done this for years, at a good weight and with normal stools, you are most likely looking at temperament, not disease.

The 2-day rule, and how it lines up with parasite timelines

The most useful finding for owners: 82% (first survey) and 85% (second survey) of stool-eaters went for fresh faeces, no more than two days old. Hart's team suggested an ancestral reason. Wolves keep the den clean, and many intestinal worm eggs are not yet infective when they are passed, so removing fresh faeces quickly protects the pack. We lined that up against current parasite guidelines from the US-based Companion Animal Parasite Council (CAPC):

So the instinct makes some sense for worms, but it is no guarantee, and it fails outright for Giardia. That is why parasite control matters more for poo-eaters than for other dogs. If you want to compare options, our guide to the best wormer for dogs covers coverage, testing and safety by parasite.

Is it dangerous for dogs to eat poo?

For most dogs eating their own fresh stool, the UC Davis authors describe the habit as "medically harmless," however unpleasant it is for you. The risk rises with other animals' faeces and with older stool:

• Intestinal parasites. Roundworms, hookworms, whipworms and Giardia spread through faecal contamination. Our overview of intestinal parasites in dogs explains how each spreads and which tests find them. Some dog roundworms and hookworms can also affect people, which is one more reason to clean up promptly and wash hands.
• Horse manure after worming. VCA and US-based Pet Poison Helpline toxicologists warn that dogs can be poisoned "even if they eat manure of horses that were recently dewormed," and dogs with the MDR1 gene mutation are especially sensitive to this ivermectin-type drug class (VCA). Wobbliness, dilated pupils, drooling, tremors or seizures after a farm walk mean a vet visit now.
• Confusing faecal tests. Researchers note that eggs from eaten stool can pass straight through a dog and produce a false-positive faecal result (Pilla et al., 2026). Tell your vet about the habit when you drop off a sample.
• Bad breath. Not a medical danger, but the reason many owners search this topic. See the section on breath below.

If stool-eating comes with worms in your dog's poo, vomiting, diarrhoea or lethargy, book a vet visit and bring a fresh sample.

When eating poo is a medical sign

The pattern that should worry you is change: an adult dog that never did this and now does, or stool-eating that arrives with other symptoms. VCA's behaviourists list these medical triggers:

• Malabsorption and digestive enzyme deficiencies. A dog that is not absorbing its food stays hungry. Exocrine pancreatic insufficiency (EPI) is one example and is diagnosed with a blood test, not guessed from a food label. Our guide to digestive enzymes for dogs explains when enzymes are a vet-directed treatment and when they are just a supplement.
• Parasites. VCA calls stool testing for parasites "the minimum level of testing." Check the signs of parasites in dogs if you are unsure.
• Drugs that raise appetite. "Treatment with certain drugs such as steroids may lead to an increase in stool eating" (VCA). If the habit started after a new prescription, call the prescribing vet. Never stop a medication on your own.
• Diseases that increase appetite, including diabetes, Cushing's disease and thyroid disease.
• Underfeeding or a poorly balanced diet, such as extreme calorie restriction.

How to stop your dog from eating poo

VCA's behaviourists put it simply: coprophagia "can best be corrected by preventing access to stools." The UC Davis data back that up, because almost nothing else worked.

1. Pick up right away. Since most dogs target stool under two days old, same-day clean-up removes the main target. In the garden, walk out with your dog and clean up before you head back in.
2. Use a lead and supervise. For established poo-eaters, go out on a lead and interrupt with a cue or a quick redirect on the lead, as VCA recommends.
3. Reward right after your dog goes. Teach your dog to come to you and sit for a high-value treat immediately after eliminating, so turning toward you becomes the habit.
4. Train "leave it." It was the best-performing approach in the survey. Its success rate was still only 4%, so pair it with supervision.
5. Slow down the greedy eater. Puzzle feeders and food-dispensing toys target the trait most strongly linked to poo eating. No study has tested whether this alone stops the habit.
6. Block the litter tray. Eating cat stool was linked to eating dog stool. Use a baby gate or a covered box.
7. Keep parasite control and faecal testing current. CAPC recommends faecal testing at least four times in the first year of life and at least twice a year in adults, with year-round parasite control. Our worm-prevention checklist walks through the reinfection loop.
8. Skip punishment. Chasing the dog away scored 1–2%, and a big reaction can reinforce the behaviour.
9. Add enrichment. Bored, under-exercised dogs scavenge more. If stress or isolation is part of the picture, our guide to dog anxiety support covers training-first options.

Do poo-eating deterrents work?

Here is what owners of 1,475 frequent stool-eaters reported in the second UC Davis survey. The products are named for accuracy only; we do not recommend or link to any of them.

These are owner recollections, not a controlled trial, and nobody recorded whether labels were followed. VCA offers one explanation: most dogs "either develop a tolerance to the taste, or learn to avoid those stools that are pretreated." A small trial in 28 dogs found that a citronella spray collar did better than sound therapy over a few weeks (Wells, 2003), but long-term results were not reported, and it is an aversive tool, so discuss it with a behaviourist first. Home remedies such as papaya, yogurt or cottage cheese "have never been proven to be effective," according to VCA.

Myths about dogs eating poo

The same "research versus folklore" pattern applies to why dogs eat grass, another scavenging habit that is usually normal.

Why Pure Majesty Pets for a scavenger's daily routine

We will not tell you a bottle stops poo eating, because no study supports that. What a daily routine can do is support the gut of a dog that samples the world with its mouth. If you are comparing gut products, our guide to the best probiotic for dogs explains what to look for on a label, and our dog gut health guide covers the bigger picture.

Why a liquid? There is no chew for a fast eater to bolt and no powder to scoop: you measure the serving shown on your bottle label and add it to a meal. On the evidence side, a placebo-controlled study in 20 dogs with chronic enteropathy, given alongside standard treatment, found that stool consistency and frequency improved significantly with S. boulardii compared with placebo (D'Angelo et al., 2018). That supports interest in the ingredient; it does not prove the effect of any finished product, and reviews of probiotics for acute diarrhoea find only limited benefit. Our breakdown of what probiotic research actually shows and our guide to probiotics for dogs with diarrhoea go deeper.

Two more parts of a poo-eater's routine:

• Breath. If the after-effects reach your face, Pure Majesty Pets Dog Dental Powder (67 NZD, 60 scoops) is a no-brush food topper with zinc citrate for breath odour plus kelp, hydroxyapatite and SHMP for daily oral care. Our article on dog bad breath lists the red flags that need a vet, and our best dog dental powder guide compares labels.
• Parasites. A supplement never replaces your vet's wormer and faecal testing. Our Parasite & Worm Support range gathers the daily-care products that sit alongside that plan.

Every Pure Majesty Pets formula is made in North America in a GMP facility, with a certificate of analysis for each batch, and every order ships free worldwide on DDP terms: duties and taxes are paid in advance, so there is nothing to pay on delivery. Explore the full range at Pure Majesty Pets.

Frequently asked questions

Why do dogs eat poo?

Mostly because it is a normal scavenging behaviour. In the largest study, 16–23% of dogs did it, greedy eaters and dogs in multi-dog homes were most likely to, and diet and age showed no link. Medical causes such as malabsorption, parasites, steroids or hormonal disease should be ruled out when the habit starts suddenly in an adult dog.

Why is my dog suddenly eating poo?

A new habit in an adult dog is a reason to see your vet. Malabsorption, intestinal parasites, appetite-increasing drugs such as steroids, underfeeding and diseases like diabetes, Cushing's or thyroid disease can all trigger it. Bring a fresh stool sample and a list of current medications.

Can dogs get sick from eating poo?

Eating their own fresh stool is usually harmless, but other animals' faeces can carry intestinal parasites such as roundworms, hookworms and Giardia. Manure from recently wormed horses can poison sensitive dogs. Keep parasite control and faecal testing on your vet's schedule.

What can I add to my dog's food to stop it eating poo?

No food additive has been shown to work. In the UC Davis survey, 11 marketed products had 0–2% owner-reported success, and VCA says home remedies like papaya, yogurt or cottage cheese have never been proven effective. Prompt pick-up, supervision and training work better.

Will my puppy grow out of eating poo?

Many do. Puppies explore and copy their mother, and VCA notes the habit usually clears up by adulthood. Supervise, clean up quickly and keep worming on schedule in the meantime.

Why does my dog eat cat poo?

Cat stool is attractive to scavengers, and eating it was linked to eating dog stool in the UC Davis data. Put the litter tray behind a baby gate or use a covered box, and scoop it often.

Do probiotics stop dogs from eating poo?

No study shows that any probiotic stops the behaviour, and research has not found that poo-eaters have an unbalanced microbiome. A probiotic such as Pure Majesty Pets Liquid Probiotic for Dogs is daily support for stool consistency and gut flora, alongside management and parasite control.

Sources

• Hart BL, Hart LA, Thigpen AP, Tran A, Bain MJ. The paradox of canine conspecific coprophagy. Veterinary Medicine and Science. 2018;4(2):106–114. PMID 29851313.
• Horwitz D, Landsberg G. Dog Behavior Problems: Coprophagia. VCA Animal Hospitals.
• Companion Animal Parasite Council. Hookworms, Ascarids and Giardia guidelines.
• VCA Animal Hospitals. Macrocyclic Lactone Poisoning in Dogs.
• Wells DL. Comparison of two treatments for preventing dogs eating their own faeces. Veterinary Record. 2003;153(2):51–53.
• Pilla R, et al. Coprophagy in healthy dogs does not alter fecal core microbiota or increase carriage of enteropathogens. Animals. 2026;16(17):2715.
• Bamberger T, et al. Mapping the canine gut microbiome: insights from the Dog Aging Project. Nature Communications. 2026;17:6602.
• D'Angelo S, et al. Effect of Saccharomyces boulardii in dog with chronic enteropathies: double-blinded, placebo-controlled study. Veterinary Record. 2018;182(9):258.

This article is for informational purposes and is not veterinary advice. Talk to your vet before starting any supplement, especially if your dog is pregnant, nursing, on medication or has a diagnosed condition, and contact your vet if your dog's behaviour changes suddenly or comes with any sign of illness.