Why Is My Adult Dog Eating Poop? | What Vets Want You

Most dog owners assume their pet eats poop because something is missing from their food. That assumption makes sense, but veterinary behavior experts say the reality is more nuanced — and often less alarming.

The technical name for the behavior is coprophagia, and while it looks unpleasant, it doesn’t automatically mean your dog is sick. For adult dogs, the reasons can range from simple boredom all the way to treatable medical conditions like endocrine disease or malabsorption. This article walks through the most common causes and helps you recognize when it’s time to call your vet.

Is This Normal for an Adult Dog?

Puppies explore the world with their mouths, and eating stool is fairly common in the first few months. But if an adult dog who never showed interest suddenly starts eating poop, that’s worth paying attention to.

According to the PDSA (a UK veterinary charity), most adult dogs who eat poop do it out of habit, hunger, stress, or boredom — and only a very small number do it because of an illness or nutritional deficiency. That distinction matters because it changes how you approach the problem.

A dog who has always been a stool-eater since puppyhood may just have a persistent habit. A dog who starts the behavior later in life, or who pairs it with other symptoms like weight loss or increased thirst, is more likely to have an underlying medical driver.

Why the “Missing Nutrients” Story Sticks

It’s easy to assume a dog who eats poop must be lacking something in their diet. And that can be true in some cases — but it’s not the most common explanation. Here’s what veterinary sources point to as the main categories:

• Medical conditions: Endocrine disorders like diabetes and Cushing’s disease, internal parasites, and malabsorption issues can all trigger coprophagia. Exocrine Pancreatic Insufficiency (EPI), where the pancreas doesn’t produce enough digestive enzymes, is one specific condition linked to stool eating.
• Poor diet or underfeeding: If a dog’s food is poorly digestible, or if they’re not getting enough calories, their body may not absorb enough nutrients — leaving undigested material in the stool that the dog then tries to reclaim.
• Boredom, stress, or anxiety: Dogs left alone for long periods, or those who don’t get enough mental stimulation, may develop coprophagia as a repetitive behavior. Cleaning up the yard can reinforce the cycle because the dog learns to “get to it first.”
• Cat poop temptation: Dogs often target cat feces because cat food is high in protein and fat, making the stool attractive. This is more about opportunity than illness.
• Senior dog concern: In older dogs, especially those with cognitive decline, stool eating may signal a different set of issues — and it’s usually worth a veterinary exam to check for problems like dementia or sensory loss.

One way to approach this at home is to look at the whole picture: recent diet changes, new medications (especially steroids), access to other pets’ waste, and any other symptoms your dog is showing. A pattern helps your vet narrow things down.

What the 2022 Coprophagia Study Reveals

Most of what vets know about coprophagia comes from clinical experience rather than large-scale trials, but a 2022 study published in PMC adds some data. Researchers looked at how coprophagic behavior influenced fecal concentrations of lactic acid, short-chain fatty acids, and branched fatty acids in dogs. The 2022 coprophagia study is a useful starting point for understanding that stool-eating dogs may have different gut chemistry, though the study didn’t test treatments or behavioral fixes.

The takeaway for owners is that if the behavior has been going on for months with no other symptoms, it’s likely behavioral rather than medical. But if it’s new, sudden, or paired with changes in appetite or energy, a vet visit should come before any home remedies.

Comparing Behavioral vs. Medical Causes

If your dog matches more items on the left side of this table, behavioral modification and management are likely enough. If the right side has more checks, a veterinary workup is the right next step.

When Should You Worry About Adult Dog Poop Eating?

A single incident of stool eating is not a crisis. But there are specific scenarios where it’s wise to schedule a vet appointment rather than wait and watch.

1. Sudden onset in an adult dog. If a dog who never ate poop as a puppy starts as an adult, that’s a red flag for a medical change — not just a bad habit.
2. Accompanied by weight loss or poor appetite. Weight loss paired with stool eating can point to malabsorption, parasites, or EPI, all of which are treatable once diagnosed.
3. Senior dogs with no prior history. Older dogs who begin eating stool may have cognitive dysfunction, sensory decline, or an underlying metabolic condition like Cushing’s disease. A thorough checkup can help rule out the serious causes.
4. Presence of other symptoms. Vomiting, diarrhea, excessive thirst, or a ravenous appetite alongside coprophagia makes a medical cause more likely.
5. No response to management changes. If you’ve been cleaning up the yard immediately, blocking access to cat litter, and adding mental enrichment, but the dog still seeks out stool, it’s worth investigating further.

Your vet may recommend fecal testing, blood work, or specific tests for pancreatic function. These are routine diagnostics that can identify conditions that are easily missed.

Practical Steps to Address the Behavior

If your vet has ruled out medical issues, the management approach focuses on reducing opportunity and redirecting the habit. The American Kennel Club’s coprophagia definition notes that in many cases, stool eating is simply a bad habit — not a sign of illness or deficiency.

The first step is immediate cleanup. Pick up stool from the yard at least once a day, preferably right after your dog eliminates. If you have cats, place litter boxes behind baby gates or in rooms the dog can’t access. Some owners find that adding a digestive enzyme supplement to the diet may help reduce the appeal of the stool, though the evidence for this approach is limited and should be discussed with your vet.

Quick Management Checklist

Behavioral modification takes patience. Most dogs who eat poop aren’t doing it out of defiance — they’re repeating a behavior that became self-reinforcing. Consistent management over several weeks can break the cycle.

The Bottom Line

Adult dogs eat poop for reasons that range from normal canine curiosity to treatable medical conditions. The key decision point is whether the behavior is paired with other symptoms. A healthy adult dog who has always eaten poop and shows no weight loss, appetite change, or gastrointestinal signs is likely behavioral. A dog who starts suddenly, loses weight, or seems excessively hungry deserves a veterinary workup to rule out parasites, EPI, or endocrine disease.

Your veterinarian can run a simple fecal test and blood panel to address the most common medical causes, and suggest management strategies tailored to your dog’s age, breed, and daily routine — whether that means adding enzymes to meals, changing the food, or simply picking up the yard more often.