There are certain questions dog owners ask themselves when heading out for walkies, one of them being: will this be a one bag excursion, or two?

Then there’s the great moment, when people are cheerfully strolling up and down the footpath whilst you, the dog owner, stand holding the leash, and yet pretending to be elsewhere as Charlie, Daisy or Zeus squat their little hearts out.

The question being asked here is: dear God how long is this going to take?

Researchers from the University of Illinois have found that poop time will be shorter, and the attendant bag load will be about two-thirds lighter, if your dog is fed “human-grade” food instead of dry, crunchy kibble.

How did they work this out? (Not with a pencil)

The research was led by Dr Kelly Swanson, the Kraft Heinz Company Endowed Professor in Human Nutrition in the Department of Animal Sciences and the Division of Nutritional Sciences at Illinois.

According to a statement from Illinois, the idea was to test the digestibility of four commercially available diets: a standard extruded diet (kibble); a fresh, refrigerated diet; and two fresh diets made using only USDA-certified human-grade ingredients.

It appears that dogs fed human-grade pet food have healthier gut bacteria than dogs fed kibble. Photo: JustFoodForDogs

These fresh diets include minimally processed ingredients such as beef, chicken, rice, carrots, broccoli, and others in small chunks or a sort of casserole.

Four beagles were fed each of these diets for four weeks at a time.

The researchers found that dogs fed the extruded diet had to eat more to maintain their body weight, and produced 1.5 to 2.9 times as much poop as any of the fresh diets.

“This is consistent with a 2019 National Institute of Health study in humans that found people eating a fresh whole food diet consumed on average 500 less calories per day, and reported being more satisfied, than people eating a more processed diet,” said Dr Swanson.

Gut microbes worked more efficiently

The researchers also found that the fresh diets uniquely influenced the gut microbial community.

“Because a healthy gut means a healthy mutt, fecal microbial and metabolite profiles are important readouts of diet assessment,” said Dr Swanson.

In previous studies, the Illinois researchers demonstrated that the fecal microbial communities of healthy dogs fed fresh diets were different than those fed kibble.

“These unique microbial profiles were likely due to differences in diet processing, ingredient source, and the concentration and type of dietary fibers, proteins, and fats that are known to influence what is digested by the dog and what reaches the colon for fermentation,” said Dr Swanson.

Surprising outcome

The researchers said that commercially available, fresh prepared whole-food diets have been around for a decade and despite anecdotal reports of health benefits, some nutrition experts were concerned about a lack of scientific evidence to support the feeding of these diets.

The Illinois team published an earlier study in roosters to show the same human-grade fresh diets were up to 40 per cent more digestible than kibble. The new study in dogs appears to support those findings.

“Based on past research we’ve conducted I’m not surprised with the results when feeding human-grade compared to an extruded dry diet,” said Dr Swanson, and co-author on the new paper.

“However, I did not expect to see how well the human-grade fresh food performed, even compared to a fresh commercial processed brand.”