Home Dog Behavior Eating Poop and Grass

Why Do Dogs Eat Poop (and Grass)?

By the Dog Health Handbook team · Updated · Fact-checked against current veterinary references (see sources)

Key takeaways

  • About 1 in 6 dogs eat poop often, usually fresh stools.
  • Diet usually isn't the cause, and food additives almost never work.
  • Pick up stools right away and teach "leave it."
  • See your vet if it starts suddenly or comes with weight loss.
  • Eating grass is normal; most dogs aren't sick beforehand.

Table of Contents

Research Why dogs eat poop Risks How to stop it Eating grass FAQ Sources

Dog Behavior Quicklinks

Behavior Problems Anxiety Aggression and Biting Barking Eating Poop and Grass Peeing in the House Dementia

Eating poop, called coprophagia, is common in dogs. About 1 in 6 dogs do it often, and nearly 1 in 4 have done it at least once.1 Most dogs that eat poop choose fresh stools, no more than a day or two old. One theory is that ancestral dogs ate fresh droppings before parasite eggs became infective.1 Greedy eaters and dogs in multi-dog homes are more likely to do it. Diet, age, sex and neutering made no difference in the largest study.1 Some medical problems that affect digestion can also be involved, so see your vet if it starts suddenly.2,3 Commercial food additives almost never work; owners reported success with them only 0% to 2% of the time.1 The best prevention is picking up poop right away, supervising your dog outside and teaching "leave it."1 Eating grass is also normal. About 8 in 10 dogs do it, and most aren't sick beforehand.4,5

See your vet if your dog:

  • Suddenly starts eating poop, or seems constantly hungry, losing weight, or has loose or greasy stools3,6
  • Seems unwell before eating grass, vomits repeatedly, or has diarrhea5
  • Has eaten horse dewormer, or manure from recently dewormed horses. Call your vet or an animal poison control line right away, because signs can start within hours.7,8
  • Has eaten raccoon droppings or plants from a chemically treated lawn9,10

What the Research Says

  • It's common and usually involves fresh poop. In UC Davis surveys of about 3,000 owners, 16% of dogs ate stools frequently. About 85% of frequent eaters chose stools no more than 2 days old.1
  • Products rarely work. Owners rated commercial deterrents successful 0% to 2% of the time. Rewarding "leave it" did best, at only about 4%.1
  • Diet isn't the cause. Most coprophagic dogs ate the same kibble diets as other dogs. A small 2022 study of 12 dogs found eating feces made little difference to digestion.1,11
  • Grass eating is normal. In a small clinic survey, 79% of owners had seen their dog eat plants. In a survey of over 1,500 owners of plant-eating dogs, only 9% of the dogs often seemed ill beforehand, and 22% often vomited afterward.4

Why Do Dogs Eat Poop?

  • Normal instinct: eating fresh stools may come from wolf ancestors keeping the den free of parasites. This theory hasn't been proven.1
  • Greedy eating: dogs their owners describe as greedy eaters are much more likely to eat poop.1
  • Living with other dogs1,11
  • Stress, anxiety, or long confinement with too little to do, or being punished when caught eating poop. Some dogs with separation anxiety eat their stools.11,12,13
  • Breed: terriers and hounds were most likely in one study. Shetland Sheepdogs were over-represented.1

Medical causes to rule out

See your vet if poop eating starts suddenly, or comes with weight loss, a big appetite or diarrhea.3,14 One medical cause is exocrine pancreatic insufficiency (EPI), where the pancreas doesn't make enough digestive enzymes. Dogs with EPI may eat their stools, along with losing weight, passing large loose stools and being very hungry. It's most common in young German Shepherds and is treated with enzyme replacement.2,3 Your vet may also check a stool sample for parasites and run blood tests.3,6

Is Eating Poop Dangerous?

Eating its own fresh stool is unlikely to harm a healthy dog, though a dog with worms can reinfect himself. Other animals' droppings carry more risk:9,15

  • Cat poop: some roundworms and hookworms can infect dogs, and Giardia can pass between species. See roundworms and Giardia.
  • Raccoon poop: can carry a roundworm that causes severe nerve damage
  • Deer, rabbit, bird and farm animal droppings: lower parasite risk, because most parasites are species-specific
  • Horse dewormer: dogs that eat horse deworming paste, or manure from recently dewormed horses, can be poisoned. Collies, Australian Shepherds and Shetland Sheepdogs with the MDR1 gene mutation are especially sensitive. See dog poisoning.7,16,8

Dog poop can also spread germs to people, so pick it up promptly, especially where children play.15

How to Stop Your Dog From Eating Poop

  1. Pick up stools immediately, since most dogs prefer fresh ones. Keep litter boxes out of reach.1,9
  2. Walk your dog on a leash and supervise yard time.1
  3. Teach "leave it" and reward your dog for coming to you after he goes.1
  4. Slow down greedy eaters with puzzle feeders, and keep your dog busy with exercise and toys.1,13
  5. Don't punish. Punishing a dog when you catch him eating poop is thought to make the habit worse.11
  6. See your vet to rule out medical causes.3,6

Food additives and home remedies have no good evidence behind them.1,11

Why Do Dogs Eat Grass?

Most dogs eat grass or other plants, and it's considered normal behavior.4,17 Most dogs don't seem sick before eating grass, and most don't vomit afterward. Vomiting seems to be a side effect, not the reason they eat it.4,5 Young dogs eat plants more often.4 Dogs eat more grass before meals, which suggests hunger plays a part.17 One theory is that it's an inherited habit that helped wild ancestors purge intestinal worms, but this hasn't been proven.5

  • Keep dogs off lawns treated with weed killers and fertilizers, and away from toxic plants.5,10
  • See your vet if your dog seems ill before eating grass, vomits often, or eats grass obsessively.5 See dog vomiting.

See also dog behavior problems.

Frequently Asked Questions

Is it normal for dogs to eat poop?

It's common, especially with fresh stools, but check with your vet if it starts suddenly.

What can I put in my dog's food to stop eating poop?

Studies found food additives almost never work. Prompt cleanup works better.

Does eating poop mean my dog is missing something in his diet?

Usually not. Research hasn't found a link with diet.

Which dogs eat poop the most?

Greedy eaters, dogs in multi-dog homes, and some terriers, hounds and Shelties.

Should I stop my dog from eating grass?

Not usually, but avoid treated lawns and see your vet if he vomits often.

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Sources and further reading

This article was written and fact-checked on October 26, 2026 against current veterinary references and specialist guidelines:

  1. Hart BL, Hart LA, Thigpen AP, Tran A, Bain MJ. The paradox of canine conspecific coprophagy. Vet Med Sci 2018;4(2):106-114. doi:10.1002/vms3.92
  2. Shillito DJ. Exocrine Pancreatic Insufficiency in a German Shepherd Dog. Senior Seminar Paper, Cornell University College of Veterinary Medicine, 2008.
  3. Steiner JM. Exocrine Pancreatic Insufficiency in Dogs and Cats. Merck Veterinary Manual (professional version), reviewed and updated September 2025.
  4. Sueda KLC, Hart BL, Cliff KD. Characterisation of plant eating in dogs. Appl Anim Behav Sci 2008;111(1):120-132. doi:10.1016/j.applanim.2007.05.018
  5. Hart BL. Why do dogs and cats eat grass? dvm360, December 1, 2009.
  6. Lindell E, Horwitz D, Landsberg G. Dog Behavior Problems: House Soiling. VCA Animal Hospitals, updated June 2026.
  7. Linek J, Spiess B, Dallmeyer C, Geyer J. Macrocyclic lactone intoxication in three dogs with and without MDR1 gene mutation caused by a dewormer paste licensed for horses (title paraphrased). Tierarztl Prax Ausg K Kleintiere Heimtiere 2007;35(1):272-276. doi:10.1055/s-0038-1622602
  8. Schmid R. Macrocyclic Lactone Poisoning in Dogs. VCA Animal Hospitals, updated September 2026.
  9. Patton Veterinary Hospital. The scoop on dogs eating poop: can dogs get sick from ingesting stool from other animals? Patton Veterinary Hospital, accessed October 2026.
  10. Hazel S, Zoanetti J. Your dog loves eating grass, but not for the reasons you think. The Conversation (republished by ScienceAlert), June 2, 2023.
  11. Vendramini THA, Gomes VZ, Anastacio GL, Henriquez LBF, Ochamotto VA, Rentas MF, et al. Evaluation of the Influence of Coprophagic Behavior on the Digestibility of Dietary Nutrients and Fecal Fermentation Products in Adult Dogs. Vet Sci 2022;9(12):686. doi:10.3390/vetsci9120686
  12. Borns-Weil S. Behavior Problems of Dogs. Merck Veterinary Manual (professional version), reviewed and updated September 2025.
  13. ASPCA. Separation Anxiety. ASPCA, accessed October 2026.
  14. Landsberg GM. Behavior Problems in Dogs. Merck Veterinary Manual (pet owner version), reviewed February 2018, updated April 2026.
  15. Centers for Disease Control and Prevention. Dogs (Healthy Pets). CDC, reviewed June 15, 2026.
  16. Hawkins R. Cash (MDR1 case story). Washington State University Veterinary Teaching Hospital, December 8, 2009.
  17. Bjone S, Brown W, Price I. Grass eating patterns in the domestic dog, Canis familiaris. Recent Advances in Animal Nutrition in Australia 2007;16:45-49.

About this article

Last updated : new page, written using UC Davis research, the Merck Veterinary Manual, the CDC and studies published 2007 to 2023.

This page is for general information and is not a substitute for an exam by your veterinarian.