Why Does My Dog Eat Cat Poop From the Litter Box?

By Jessica Ennis, DVM, CVA

✓ Medically reviewed by Jessica Ennis, DVM, CVA — August 17, 2026 For general education — not a substitute for veterinary care.

Behavior · August 21, 2026 · 5 min read

Most litter-box raiding is a dog following its nose to a high-protein snack, not a sign anything is wrong, but a few checks rule out the exceptions.

The quick read, before the explanation:

• Cat food is high in protein and fat, and cat digestion leaves more of both behind in the stool than dog food does — that residue is the draw, not a deficiency in your dog.
• Rule out medical causes first if the habit is new, sudden, or paired with weight loss, diarrhea, or a ravenous appetite — pancreatic insufficiency and parasites both fit that picture.
• Access is the single biggest predictor. A box a dog can reach gets raided; a box a dog can’t reach doesn’t.
• Anxious or under-stimulated dogs raid more. If the behavior tracks with stress (new pet, schedule change, thunderstorms), the trigger isn’t the litter box at all.
• Covered boxes, baby gates, and litter furniture solve most cases faster than any product on the market.

I’ve had this exact conversation more times than I can count, usually opening the same way: “I know it’s disgusting, but is it actually a problem?” My answer is almost always some version of probably not, but let’s check the short list first.

The myth: it means something is missing from the diet

Owners often arrive assuming their dog has a nutritional gap — some missing enzyme or mineral driving the behavior, the same instinct behind eating grass or dirt. For litter-box raiding specifically, that’s rarely the explanation. Cat food is formulated with a much higher protein and fat content than dog food, because cats are obligate carnivores with different metabolic needs. A meaningful share of that protein and fat passes through undigested and ends up in the stool, which makes cat feces smell — to a dog’s nose — a lot like a snack. It’s a scavenging instinct responding to a genuinely appealing scent profile, not evidence that your dog’s own diet is inadequate.

The exception: when it’s actually a medical flag

That said, I don’t wave every case off, because a subset of these dogs are eating stool — cat, dog, or otherwise — because something underneath is driving true hunger or a malabsorption problem. In my practice, the dogs I take a second look at share a pattern: the behavior started suddenly in an adult dog with no prior interest in the litter box, it’s paired with weight loss despite a normal or increased appetite, and the stool itself is soft, greasy, or unusually large in volume. That combination points toward exocrine pancreatic insufficiency, intestinal parasites, or a malabsorptive disease, all of which can leave a dog functionally hungry even after a full meal. I had a seven-year-old German Shepherd, about 68 pounds, whose owner mentioned almost as an aside that he’d started cleaning out the litter box every morning before she got downstairs — a habit that hadn’t existed for the first six years of his life. He’d also dropped nearly ten pounds over two months despite eating well. Bloodwork confirmed pancreatic insufficiency. That’s the case that keeps me from ever calling coprophagia “just gross but harmless” without asking a few questions first.

Reading the reality: what actually predicts the behavior

Set aside the diet myth and the medical exception, and access is the strongest predictor left. Dogs raid what they can reach. A box tucked in an open laundry room at floor level gets visited daily; a box behind a baby gate, up a step, or inside a covered enclosure gets visited rarely if at all. Boredom and stress add to the pull — a dog left alone for long stretches, or one going through a change like a new pet in the house, a move, or a shift in routine, tends to explore and scavenge more, and the litter box is often the most interesting, most accessible thing in the room.

That’s a short list of factors. It’s also usually enough.

Where calming support genuinely fits, and where it doesn’t

For dogs whose litter-box interest tracks with an anxious or stressed baseline rather than simple curiosity, calming nutritional support can be a reasonable piece of a broader plan — never a stand-alone fix, and never a substitute for closing off physical access. Chamomile and valerian root have a long history of traditional use to support relaxation, though for chamomile specifically, current evidence in most species is still mainly preclinical or drawn from that traditional-use record rather than robust clinical trials, per a 2026 review in Biomedicines. Ashwagandha has firmer human data behind it: a systematic review published in Cureus found that KSM-66 ashwagandha had a moderate positive effect on stress reduction and cognitive performance across multiple randomized trials. L-theanine’s evidence is narrower still — outside of one trial on psychotic anxiety using 400 mg/day over eight weeks, a 2026 review in Molecular Psychiatry found effects were otherwise limited, and that dose comes from human research, not dogs. I mention that gap on purpose: it’s tempting to round “may help support calm” up to “will stop the behavior,” and I don’t think the evidence earns that leap yet.

The sequence I actually walk owners through

1. Block physical access. A covered box, a baby gate cats can jump but dogs can’t, or litter furniture with a small cat-sized opening solves the majority of cases within days.
2. Scoop more often. Less time for stool to sit means less opportunity, full stop.
3. Watch the whole picture, not just the habit. New-onset raiding plus weight loss, diarrhea, or a ravenous appetite is a vet visit, not a training project.
4. Address boredom and stress directly — more structured exercise, enrichment, and predictable routine, alongside calming support if anxiety is clearly part of the pattern rather than assumed.
5. Reassess in two to three weeks. If access is fully blocked and the interest hasn’t faded, that’s worth a follow-up conversation with your vet.

The bottom line

Most of the time, this is a scent-driven scavenging habit with an easy fix: control access, scoop often, and move on. I don’t spend much time worrying about it in an otherwise healthy dog with no other symptoms — and I say that the same way I’d say it across the exam table, expectation first, then the plan. Where I do slow down is new-onset raiding paired with weight change or a hungrier-than-usual dog, because that combination has, in my experience, meant something more than curiosity often enough to be worth ruling out. If your dog’s coprophagia looks more like a stress response than a snack run, the same groundwork that helps with other anxiety-linked habits — see our guides on boredom versus separation anxiety and chewing out of boredom or anxiety — tends to apply here too, and a look at how the behavior compares to barrier frustration versus aggression can help sharpen what you’re actually watching for.