A new study finds that dogs fed fresh human-grade food don't need to eat—or do their business—as much.
- Most dogs eat a diet that's primarily kibble.
- When fed a fresh-food diet, however, they don't need to consume as much.
- Dogs on fresh-food diets have healthier gut biomes.
Four diets were tested<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjY0NjIxMn0._w0k-qFOC86AqmtPHJBK_i-9F5oVyVYsYtUrdvfUxWQ/img.jpg?width=980" id="1b1e4" class="rm-shortcode" data-rm-shortcode-id="87937436a81c700a8ab3b1d763354843" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: AntonioDiaz/Adobe Stock<p>The researchers tested refrigerated and fresh human-grade foods against kibble, the food most dogs live on. The <a href="https://frontierpets.com.au/blogs/news/how-kibble-or-dry-dog-food-is-made" target="_blank">ingredients</a> of kibble are mashed into a dough and then extruded, forced through a die of some kind into the desired shape — think a <a href="https://en.wikipedia.org/wiki/Food_extrusion" target="_blank">pasta maker</a>. The resulting pellets are sprayed with additional flavor and color.</p><p>For four weeks, researchers fed 12 beagles one of four diets:</p><ol><li>a extruded diet — Blue Buffalo Chicken and Brown Rice Recipe</li><li>a fresh refrigerated diet — Freshpet Roasted Meals Tender Chicken Recipe</li><li>a fresh diet — JustFoodforDogs Beef & Russet Potato Recipe</li><li>another fresh diet — JustFoodforDogs Chicken & White Rice Recipe.</li></ol><p>The two fresh diets contained minimally processed beef, chicken, broccoli, rice, carrots, and various food chunks in a canine casserole of sorts. </p><p>(One can't help but think how hard it would be to get finicky cats to test new diets. As if.)</p><p>Senior author <a href="https://ansc.illinois.edu/directory/ksswanso" target="_blank" rel="noopener noreferrer">Kelly S. Swanson</a> of U of I's Department of Animal Sciences and the Division of Nutritional Sciences, was a bit surprised at how much better dogs did on people food than even refrigerated dog chow. "Based on past research we've conducted I'm not surprised with the results when feeding human-grade compared to an extruded dry diet," he <a href="https://aces.illinois.edu/news/feed-fido-fresh-human-grade-dog-food-scoop-less-poop" target="_blank">says</a>, adding, "However, I did not expect to see how well the human-grade fresh food performed, even compared to a fresh commercial processed brand."</p>
Tracking the effect of each diet<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3NjY1NTgyOX0.AdyMb8OEcjCD6iWYnXjToDmcnjfTSn-0-dfG96SIpUA/img.jpg?width=980" id="da892" class="rm-shortcode" data-rm-shortcode-id="880d952420679aeccd1eaf32b5339810" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Patryk Kosmider/Adobe Stock<p>The researchers tracked the dogs' weights and analyzed the microbiota in their fecal matter.</p><p>It turned out that the dogs on kibble had to eat more to maintain their body weight. This resulted in their producing 1.5 to 2.9 times the amount of poop produced by dogs on the fresh diets.</p><p>Says Swanson, "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."</p><p>Maybe even more interesting was the effect of fresh food on the gut biome. Though there remains much we don't yet know about microbiota, it was nonetheless the case that the microbial communities found in fresh-food poo was different.</p><p>"Because a healthy gut means a healthy mutt," says Swanson, "fecal microbial and metabolite profiles are important readouts of diet assessment. As we have shown in <a href="https://academic.oup.com/jas/article/92/9/3781/4702209#110855647" target="_blank">previous studies</a>, 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."</p>
How did kibble take over canine diets?<p>Historically, dogs ate scraps left over by humans. It has only been <a href="https://www.thefarmersdog.com/digest/the-history-of-commercial-pet-food-a-great-american-marketing-story/" target="_blank">since 1870</a>, with the arrival of the luxe Spratt's Meat Fibrine Dog Cakes—made from "the dried unsalted gelatinous parts of Prairie Beef", mmm—that commercial dog food began to take hold. Dog bone-shaped biscuits first appeared in 1907. Ken-L Ration dates from 1922. Kibble was first extruded in 1956. Pet food had become a great way to turn <a href="https://www.dogfoodadvisor.com/choosing-dog-food/animal-by-products/" target="_blank">human-food waste</a> into profit.</p><p>Commercial dog food became the norm for most household canines only after a massive marketing campaign led by a group of dog-food industry lobbyists called the Pet Food Institute in 1964. Over time, for most households, dog food was what dogs ate — what else? Human food? These days more than half of U.S. dogs are <a href="https://www.nytimes.com/2014/08/03/magazine/who-made-that-dog-biscuit.html" target="_blank">overweight or obese</a>, and certainly their diet is a factor.<span></span></p><p>We're not so special among animals after all. If something's healthy for us to eat—we're <em>not</em> looking at you, chocolate—maybe we should remember to share with our canine compatriots. Not from the table, though.</p>
A study explores how your dog does when you're not home.
- Just exactly how much are dogs upset when we leave?
- A new study finds that dogs spend time looking for us after we're gone.
- The experiment also found that dogs are more relaxed when we give them an affectionate, gentle petting before leaving.
The study<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDk5NzY2NS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NTkwOTA1OX0.l4TThBGoW9yNIlWqkCBNEHJ3UtcNqnXsGSNhAR3dXCg/img.jpg?width=980" id="3f4a3" class="rm-shortcode" data-rm-shortcode-id="7c2754204e6ff49638bfc77a7017912a" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="1029" />
Credit: SUJIN/Adobe Stock<p>The researchers conducted experiments with 10 healthy dogs between 1-11 years old and without unusual attachment issues. Six were spayed females and four were neutered males. The group was composed of seven mixed-breed dogs, one Labrador retriever, one <a href="https://en.wikipedia.org/wiki/Hovawart" target="_blank">Hovawart</a>, and one Chihuahua.</p><p>The tests were conducted in an outdoor, fenced-in area and were videotaped for later analysis. Their owners walked their leashed dogs into the fenced area where they greeted a researcher, AKA Test Leader 1. A second researcher measured the dog's heartbeat using a <a href="https://www.dictionary.com/browse/phonendoscope" target="_blank">phonendoscope</a> and quickly departed.</p><p>Each dog was tested twice. In the first test, called the NGT ("No Gentle Touch") test, the owner and Test Leader 1 chatted for minute, essentially ignoring the dog. For the second, WGT ("With Gentle Touch") test, the owner petted the dog during the one-minute Test Leader 1 chat.</p><p>In both tests, after the brief chat, the owner handed the leash to Test Leader 1 and hid behind a shed for three minutes at a distance considered too far for the dog to pick up its owner's scent. The dog was free to move around the enclosure to the extent that the 1.5 meter leash allowed. The dogs spent a significant amount the time looking for their owner—in three minutes, they searched for between 84.5 and 87.5 seconds.</p><p>After the separation, Team Leader 1 called over the owner, and the leash was handed off. After 15 minutes of light activity, the dog's saliva was tested for the presence and level of the stress hormone cortisol.</p>
Petted pet<p>All dogs participated in both tests, separately. Tests were spaced 5-9 days apart and took place at roughly the same times for consistency of cortisol levels.</p><p>The researchers found that when dogs had been petted they exhibited a more relaxed demeanor during the separation.</p><p>The canines' heart rates were tested before and after separation—they may have been elevated from the start from the car trip to the test site. After the NGT test, dogs' heart rates were unchanged by the separation. After the WGT test, dogs' heart rates actually went down, indicating the experiment left them <em>more</em> relaxed than they were when they arrived.</p><p>Cortisol levels were the same after both tests.</p>
A new study tracks the human-dog relationship through DNA.
- The earliest dog, not wolf, found so far comes from over 15,000 years ago.
- A new study tracks the travel and development of dogs since the end of the Ice Age.
- Insights are derived by comparing ancient canine DNA with ancient human DNA.
DNA gets around<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDY2NDU3NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxNzkyNH0.K0JEM0y89zL-HIr_8Z_iPW-ypbebDjFBNjXAkPraqok/img.jpg?width=980" id="de25c" class="rm-shortcode" data-rm-shortcode-id="3bec27e152f342b23e248227e2697222" data-rm-shortcode-name="rebelmouse-image" data-width="1200" data-height="840" />
Assyrian dog relief
Credit: Wikimedia Commons<p>The research is the product of a collaboration between Larson and paleogenomicist <a href="https://www.crick.ac.uk/research/find-a-researcher/pontus-skoglund" target="_blank">Pontus Skoglund</a> of the UK's Francis Crick Institute. Skoglund is an expert in canine evolution, working with teams at both institutions as well as the University of Vienna.</p><p>The researchers analyzed DNA from over 2,000 sets of canine skeletal remains, some of which dated back as far as 11,000 years. Working with ancient DNA from Siberia, Europe, and the Near East, the researchers were able to add 27 newly sequenced dog genomes to the previously sequenced five.</p><p>The researchers compared the canine DNA to the genomes of 17 human individuals who lived during the same time frames in search of common influences that might further establish their connection. Indeed, correspondences were seen that reflected the impacts of humans bringing their dogs along with them as they migrated around the world.</p><p>They found that Swedish farmers and their dogs are both descended from canines of the Near East, suggesting that man and dog followed the development of agriculture together through Europe. On the other hand, German farmers 7,000 years ago came from the Near East, but their dogs didn't.</p>
Lineages intersect<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDY2NDU3OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MjE0NDc3OH0.XLvmAchMESbLY0beM-j1NTR80JGvAWOsqzJeXjH6JGI/img.jpg?width=980" id="af19d" class="rm-shortcode" data-rm-shortcode-id="7ade8431e978b8bd5adfcecaa06697c7" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Sabine Schönfeld/Adobe Stock<p>Based on their analysis, the scientists assert that by 11,000 years ago, just after the Ice age, there were already five distinct families (or lineages) of dogs, so the German remains were no outlier. These lineages eventually developed into later lines.</p><p>Some of this occurred through interbreeding with other dogs and also through mating with their wild wolf cousins. Comparisons between ancient dog and wolf DNA revealed a surprise: Wolves picked up DNA from dogs, but, at least judging by the remains available, there was little or no gene flow back in the other direction. Larson <a href="https://www.sciencemag.org/news/2020/10/how-dogs-tracked-their-humans-across-ancient-world" target="_blank">suggests</a> to Science that the evidence may have been tampered with, so to speak — if a dog started behaving like a wolf, its human may well have simply gotten rid of it. </p><p><a href="https://www.crick.ac.uk/research/find-a-researcher/anders-bergstrom" target="_blank">Anders Bergström</a> is the lead author of the study, and he <a href="https://www.crick.ac.uk/news/2020-10-29_study-of-ancient-dog-dna-traces-canine-diversity-to-the-ice-age" target="_blank" rel="noopener noreferrer">points out</a> a mystery it reveals: "If we look back more than four or five thousand years ago, we can see that Europe was a very diverse place when it came to dogs. Although the European dogs we see today come in such an extraordinary array of shapes and forms, genetically they derive from only a very narrow subset of the diversity that used to exist." Why — and how — one line of dogs so dominated early Europe as to wipe out other lineages remains a mystery. The researchers found no human development that mirrors, or could explain, this event.</p>
A dog's life<p>It's fun to realize that ancient dog lineages persist to this day. It turns out Chihuahuas have traces of ancient American dogs, and Huskies bear traces of their cold-weather ancestors. Skoglund tells Science that on any given day in a modern dog park, you may be looking at lineages that date back 11,000 years.</p><p>It's likely that subsequent research will reveal even more. Says co-author and University of Vienna group leader Ron Pinhasi, "Just as ancient DNA has revolutionized the study of our own ancestors, it's now starting to do the same for dogs and other domesticated animals. Studying our animal companions adds another layer to our understanding of human history."</p>
New research sees dogs checking a North-South axis on their way home.
- As dogs navigate, they appear to be using the Earth's magnetic fields.
- 170 dogs orient themselves to north and south as they plot shortcuts back to their people.
- Dogs join the growing number of magnetism-sensitive animals.
Guessing the secrets of canine navigators<p>That dogs have excellent navigational talents is nothing new. The study recalls "messenger dogs" that were relied on during World War I to ferry sensitive communiqués back and forth across battle lines. In addition, of course, hunting dogs, or "scent hounds," have long exhibited the ability to return to their owners' positions, and previous studies have shown that they often devise new return routes, as opposed to simply retracing their steps. How they do this has been a bit mysterious, as the study notes: "Dogs often homed using novel routes and/or shortcuts, ruling out route reversal strategies, and making olfactory tracking and visual piloting unlikely."</p><p>In trying to figure out how dogs do what they do, researchers have divided their methods into three possible modes:</p><ul><li>tracking — following their own scent trail back to their point of origin</li><li>scouting — searching for a new, shorter way back to their point of origin</li><li>visual piloting — using landmarks to find their way back</li></ul><p>Benediktová's research began when she put video cameras and GPS trackers on four dogs, took them out into the forest, and set them loose. As might be expected, they took off in pursuit of some interesting scent. All of the dogs eventually returned. She mapped the collected GPS data, seeing runs of both tracking and scouting.</p><p>However, when she showed her maps to Burda, he noticed something else. Just before scouting their way back, the dogs did something odd: They ran for roughly 20 meters along a precise north-south axis, as if orienting themselves, before returning to Benediktová. Without some form of magnetic sensitivity, this would not be possible.<br></p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUwMjY4OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjg2MDkyNX0.IxUIornhkTGk8aOxMclbByDmKW82FO4O6nXJ9-4Vpko/img.jpg?width=980" id="93a31" class="rm-shortcode" data-rm-shortcode-id="54d17432f595df655c0b8a8afe084956" data-rm-shortcode-name="rebelmouse-image" data-width="1500" data-height="1444" />
Image source: Benediktová, et al
Testing the theory<p>A sample of four dogs is hardly definitive, so student and advisor developed a larger study involving 27 dogs who were taken on several hundred scouting trips over the course of three years. The dogs were typically taken to locales with which they had no familiarity, and the researchers avoided tipping off the canines with any navigational clues including the avoidance of situations in which wind could carry their scent toward the dogs. The researchers also hid after releasing their charges to make sure they weren't visible to the pooches.</p><p>In the end, the researchers documented 223 scouting runs in which the dogs averaged a return to their points of origin of about 1.1 kilometers (around 0.7 miles).</p><p>In 170 of these runs, the dogs did indeed repeat the smaller sample's behavior, running about 20 meters along a north-south axis. Just as intriguingly, it was these dogs who found the fastest, most direct route back. "I'm really quite impressed with the data," biologist Catherine Lohmann of the University of North Carolina, Chapel Hill, who was not involved in the study, tells <a href="https://www.sciencemag.org/news/2020/07/dogs-may-use-earth-s-magnetic-field-take-shortcuts" target="_blank">Science</a>.</p><p>Burda considers the dogs' seeming reliance on their north-south jog to be pretty convincing: "It's the most plausible explanation."</p> <div class="rm-shortcode" data-media_id="1W7raq4T" data-player_id="FvQKszTI" data-rm-shortcode-id="f1f23d529719339a12114da473a619ca"> <div id="botr_1W7raq4T_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/1W7raq4T-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/1W7raq4T-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/1W7raq4T-FvQKszTI.js"></script> </div>
Proving the theory<p>Commenting on the research, dog behaviorist Adam Miklósi at Eötvös Loránd University tells Science, "The problem is that in order to 100% prove the magnetic sense, or any sense, you have to exclude all the others."</p><p>Given the difficulties of doing that, Benediktová and Burda intend to test their hypothesis from the other direction, seeing if they can confuse dogs' magnetnoreception by placing magnets on their collars and repeating the tests — if they no longer do their little north-south jog, a reliance on the Earth's magnetic field would look even more likely. </p>
Admit it, caring for your pet can make you happy too. Science is working on why.
- A study shows that caring for your pets can improve your well-being.
- The researchers found the act of caring provided more improvements than mere companionship.
- These results aren't limited to pets. Plenty of studies show caring for others can improve your well-being.