Study: Hemp in Dog Food May Boost Gut Health

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A new peer-reviewed study out of Thailand adds real weight to something pet owners and hemp advocates have been saying anecdotally for years: hempseed products, when mixed into dog food, may actually improve digestive health without throwing the gut's bacterial ecosystem out of balance. The research, first reported by Marijuana Moment on July 24, 2026, was published in the journal Veterinary Sciences and led by a team at Kasetsart University in Thailand, one of the country's oldest agricultural research institutions.

The findings land at an interesting moment. Cannabis-derived ingredients for pets have become their own small industry over the last several years, with CBD chews and hemp oil supplements sold in pet stores and online despite the fact that no federal regulator has actually approved hemp as an ingredient in commercial pet food. That gap between consumer demand, scientific curiosity, and regulatory caution is exactly what makes this study worth unpacking in some detail.

Inside the Study: How Researchers Tested Hemp on Dogs

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The Kasetsart University team designed a fairly straightforward controlled feeding trial. Researchers recruited 24 mixed-breed dogs and split them evenly into three groups, then tracked them over a 90-day period, long enough to observe more than a short-term digestive blip and actually see how a dog's gut microbiome settles in over time.

Group one received food formulated with an 11 percent concentration of a fiber-rich hempseed byproduct, essentially the leftover plant matter after hempseed oil has been pressed out, which is high in indigestible fiber that can feed beneficial gut bacteria. Group two got a more modest addition, food supplemented with 2 percent hempseed oil, a fat-heavy ingredient rather than a fiber-heavy one. Group three served as the control, eating a standard diet with no hemp additive at all.

To measure what was actually happening inside each dog's digestive tract, researchers collected fecal samples at three points: a baseline before the trial began, then again at the 30-day mark and the 90-day mark. Comparing those samples let the team track how microbial populations shifted over time within each group, rather than relying on a single snapshot that might miss slower-developing changes. It's a reasonably rigorous design for this kind of pet nutrition research, and the extended timeline is notable given how much hemp-and-pet literature to date has relied on shorter observation windows.

What the Data Showed About Gut Bacteria

Dogs fed diets supplemented with hempseed oil showed the greatest increase in gut microbial species richness—about three times that of the control diet—while hempseed fiber byproduct also outperformed the control.

The most striking result came out of the hempseed oil group. Dogs fed the 2 percent oil diet showed a larger increase in microbial species richness compared to both the fiber-byproduct group and the untreated control. In plain terms, their guts ended up hosting a more diverse population of bacteria, which researchers generally view as a marker of digestive resilience rather than a red flag.

That oil-fed group also saw a rise in Lactobacillaceae, a bacterial family long associated with gut health benefits in both humans and animals, showing up in everything from yogurt cultures to probiotic supplements. More Lactobacillaceae generally correlates with better digestive stability and, in some research, a stronger gut barrier against opportunistic pathogens.

The fiber-rich hempseed byproduct told a slightly different story. Instead of boosting Lactobacillaceae, it drove up levels of Actinobacteriota, a separate bacterial phylum that plays its own role in breaking down complex plant fibers. That's a logical fit given the byproduct's composition, and it suggests the oil and the fiber byproduct aren't interchangeable in terms of the fermentation strategy that's activated in the gut, even though both come from the same plant.

Maybe the most reassuring detail for anyone worried about destabilizing a dog's digestion: a core set of 19 bacteria species remained present across all three diets throughout the full 90 days. That consistency indicates neither hemp formulation disrupted the dogs' baseline gut ecosystem. The researchers concluded that hempseed ingredients, whether delivered as oil or as a fiber-rich byproduct, can be safely worked into dog food formulations while offering a measurable gut health benefit.

This Isn't the First Study to Look at Hemp and Dog Gut Health

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This Kasetsart study doesn't stand alone. It's the latest entry in a growing body of research examining what cannabis and hemp compounds do to canine and even human gut biology, and the pattern showing up across these studies is becoming harder to dismiss as coincidence.

Back in 2021, researchers at the University of Nevada, Reno studied a hemp-hull fiber product branded Bio Gut Fiber and its effects on human gut microbes, an earlier signal that hemp's fibrous byproducts might carry prebiotic value beyond just the pet food world. Then in 2023, an Italian research team looked specifically at home-made dog diets incorporating hulled hemp seeds and found the seeds improved microbiota structure while significantly reducing oxidative stress markers in the dogs' blood serum, a finding that points to benefits extending beyond digestion alone and into broader metabolic health.

Taken together with the new Thai research, these studies form a reasonably consistent thread: hemp-derived ingredients, in various forms and concentrations, keep showing up as neutral-to-positive for gut health in dogs rather than something that causes disruption or harm.

Meanwhile, the commercial market hasn't waited around for the science to fully mature. A sizable and growing pet supplement industry already sells hemp seed and CBD-infused products for dogs and cats, marketed for everything from anxiety to joint pain to digestive support. Much of that market operates in a regulatory gray area, since, as the next section covers, federal and state feed authorities haven't formally signed off on these ingredients.

Why Hemp Still Isn't Approved as a Pet Food Ingredient

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Despite the encouraging research, hemp still has no official green light as a pet food ingredient in the United States, and that's a bureaucratic reality separate from anything the science shows. The Association of American Feed Control Officials, known as AAFCO, maintains an Official Publication listing every ingredient definition and approved food additive petition for animal feed. As of now, there are no approved food additive petitions or finalized ingredient definitions covering hemp derivatives in that publication.

The FDA, for its part, has stated it's unaware of any generally recognized as safe, or GRAS, conclusions that would cover hemp derivatives in animal food. Without either an AAFCO ingredient definition or an FDA GRAS determination, hemp products exist in a kind of regulatory limbo. Hemp isn't yet permitted federally as stock feed either, and AAFCO has said that stakeholders need to first weigh any potential adverse impacts before that changes.

Progress is happening, just slowly. The Hemp Feed Coalition, an industry group pushing for regulatory clarity, submitted its first application to AAFCO covering hempseed cake and meal for poultry back in February of a prior year, and that application remains under review with no final resolution yet.

That leaves a real gap between where the science is heading and where federal policy actually sits. Studies keep producing encouraging, consistent results on gut health and safety, but ingredient approval processes move at their own institutional pace, shaped as much by regulatory caution and stakeholder negotiation as by any single body of research.

Three independent research efforts now, spanning Thailand, Italy, and the United States, have looked at hemp's effect on canine or related gut microbiomes and landed on some version of the same conclusion: hemp-derived ingredients tend to support digestive health rather than undermine it, and they don't appear to knock a stable gut ecosystem out of balance. That's a meaningfully consistent pattern for a relatively new area of veterinary nutrition research, and it's likely to keep drawing scientific interest as more labs take a look.

But good data isn't the same thing as legal clearance. Whether hemp additives actually show up as standard, approved ingredients in commercial dog food bags on store shelves depends on decisions made by AAFCO and the FDA, not on how many peer-reviewed papers pile up in journals like Veterinary Sciences. That approval process moves on its own timeline, and the Hemp Feed Coalition's still-pending poultry feed application is a decent indicator of just how long these things can sit in review.

In the meantime, pet owners curious about hemp products for their dogs should check what's actually legal to sell and buy in their particular state, since hemp and CBD pet product rules vary considerably depending on where you live. And regardless of what the research shows, it's worth talking to a veterinarian before changing a dog's diet or adding any new supplement, hemp included.