Our lovable canine companions are the center of our world. They’re a part of the family—named, fed, and loved dearly.
Because your furry friend might feel more like a child than a pet, it can be easy to forget quite how different we are from our canine companions. Take, for instance, the process of digestion. While we both love food and might lick our lips at the prospect of lunchtime, the act of digesting food looks vastly different for us both. But how does a dog’s digestive system differ from ours?
Find out everything you need to know about the dog digestive system below.
The Dog Digestive System
To truly understand how dog digestion works, we need to start at the beginning.
- Chewing and Swallowing – Dogs have 42 teeth, relative to our 32. They’re sharper and leaner, designed to tear and chew through tough surfaces.
- Saliva – For humans, the production of saliva and its interaction with food is the kickoff to our digestive process. This isn’t the case for dogs since their saliva doesn’t contain any amylase. This was one of the primary discoveries of the dog digestion process, with articles from as early as 1907 addressing the “uniform failure of dog’s saliva.”
To the Stomach and Beyond
The Stomach – For dogs, digestion truly begins in the stomach. Here, the dog produces three core digestive enzymes that start to breakdown proteins:
The sheer amount of acid produced by a dog’s stomach is one of the most startling differentiators between their digestive system and our own. Dogs are likely to produce up to 100 times the amount of acid than that of a human stomach. This means that they rapidly break down proteins and have little hindrance at softening bone matter or grizzly bits that would be impossible for a human to digest.
- The Intestines – After the stomach and enzymes have done their work, what’s left is food that’s a sloppy, churned consistency, much like excrement. This passes through the small intestine, which is where any beneficial nutrients are absorbed into the bloodstream. The small intestine is composed of three parts:
- The duodenum – This intersects with the gall duct and mainly serves to alkalize the stomach acid in the digested contents.
- The Ileum – This is covered in thousands of tiny micro-vili that move the contents along, working to absorb nutrients and remove any waste.
- The Jejunum – This is followed by the large intestine, a muscular tube that serves as the final step of the journey. There’s no more nutrient absorption after the colon, rather, the walls of the large intestine produce a mucous-based substance that quickens and eases transportation to the rectum.
- Beneficial Nutrients – Once absorbed, nutrients become glucose, which travels around the entirety of the dog’s body to provide energy.
The dog digestive tract takes the shortest amount of time than any other living mammal, just eight hours in total.
Similarities Between the Human and Dog Digestive System
It should be noted that there are some similarities between a humans’ and dogs’ digestive system. Comparisons include:
Susceptibility to Heart Burn
One thing we have in common with our canine friends is that we are both susceptible to the pesky pangs and tweaks known as heartburn. These are commonly caused by an overproduction of acid.
Although you and your dog might have similar symptoms, it’s important not to be overzealous in the assumption that this means you can share medicine. Seek advice from a veterinary expert and purchase some over the counter anti-acids specifically for your dog. Sharing human antacid brands is ill-advised and risky since dogs are far more susceptible to food poisoning and the negative effects of bacteria.
We’re Both Omnivorous
Much like our canine companions, human beings are omnivores, meaning that we sustain a diet of both plant life and meat. In ancient times, dogs were depicted as purely carnivorous. This begs the question: are dogs innately omnivorous? There is much debate that surrounds the origin of a dogs’ herbivore tendencies. That said, the following two factors are crucial in the argument for their natural omnivorous nature:
- Wolf Behavior – Cousins of the canine family, researchers typically study wild wolves to gain a more thorough understanding of innate dog behavior. Wolves are known to store and binge on red berries and to enjoy grain and seed-based elements of their diet. Upon killing, they’ll even enjoy the seeds or grains in the stomach of their prey.
- Intestinal Size – True carnivores, such as cats, only need a short intestine to digest their food. Comparatively, true herbivores require something quite longer. Humans, dogs and other omnivorous creatures all share a mid-sized intestine to ease the digestion of both food types.
The vitality of a dog’s digestive system means that they are far more tolerant of raw meats and unlikely to be affected by some of the pathogens or bacteria that humans are unable to stomach. Despite that, you’ll notice that store-bought dog food doesn’t typically contain raw meat. The reason for this is more for our benefit than our pooch. Since pathogens from raw foods are responsible for over 14 Million illnesses and over 1,800 annually in the United States, the FDA does not grant approval for any dog or animal branded food containing uncooked meat.
Maintaining Dog Digestive Health
As a dog owner, maintaining the health of your dog’s digestion will be one of your top priorities. It’s common for dogs to experience some kind of digestive problems in their lifetime, though it may be just an upset stomach. The symptoms are easy to spot: shying away from their food, a change in excrement consistency, or an increase in flatulence. If you recognize any of these changes in your dog, consider making the following adjustments to their diet:
- Increase Vitamin and Minerals – Many dog foods boast their vitamin count as their proudest accolade. The reason being is that vitamins and minerals have a huge impact on the number of beneficial nutrients that your dog ultimately absorbs. If your dog is experiencing some kind of mineral deficiency, then you might want to add a nutritional supplement to your dog’s diet.
- Switch Protein – If you have a trusted brand of dog food that you stick to, then your dog is likely getting little to no protein variation in their diet. If your dog is strictly eating chicken, it might be beneficial to mix up their diet with the addition of some fish- or cow-based foods.
- Eliminate Free-Feeding – If you want to make a thorough analysis of your dog’s digestion process, it’s important to treat it like a controlled experiment. This is impossible if your dog is free feeding throughout the day, since you’ll have no idea what food intake results in which stool. Most vets recommend ceasing the free-feed and instead establishing a measured and regular dinner time.
- Alter the Consistency – Similarly, try breaking patterns of dry, wet or canned eating.
The Importance of Gut Health
Now, let’s turn to a less explored facet of the dog digestive system: the gut biome. The gut biome is known to determine everything from what gets absorbed and how much to your dog’s mood and brain functionality. You read that right! Your dog’s gut health matters.
The gut biome can be described by two different prefixes: probiotics and prebiotics. Probiotics are live bacteria that are housed inside your dog’s gut. They help break down any food that enters the digestive tract. Prebiotics are the fertilizer, or food source, for probiotics—they’re the fibers and nutrients found in vegetables, fruits, and meat. Without a healthy, balanced biome of probiotics, these vitamins and minerals never get absorbed into the body.
No-Go Food for Your Dog
No matter what you’re eating, your dog is going to show interest. No matter how endearing their puppy eyes, or how obediently they sit before you, it’s crucial that you only feed your dog food that you know their digestive system can handle. As a responsible dog owner, make it your intention to be an expert in dog digestive health so that you never run the risk of making your dog ill through food intake.
No matter how much you might enjoy them, the following foods are simply not safe for your dog:
- Ice Cream – While sugar is generally considered a “no no” for dogs, many animals are also lactose intolerant. For this reason alone, vets advise that it isn’t worth the risk to feed your dog ice cream.
- Chocolate – We teach children that chocolate is “poisonous” for dogs. This statement, although dramatic, is not false. Chocolate contains a substance called Methylxanthine which is highly toxic to dogs and can completely halt their metabolic process.
- Allium Food Group – Dogs should avoid any food in the allium food group. This means onions, garlic, chives and the likes of are completely off the table. Alliums contain thiosulfate that will give your dog amnesia, which can cause an increased heart rate, loss of strength, and a disruption of their organ systems. Alliums are particularly sinister in that they produce a delayed reaction, so your dog might seem fine following immediate consumption. Don’t let this deter you from taking your dog to the vet if you know that they have, in fact, consumed an allium.
- Almond Nuts – While almonds themselves are not toxic, their shape and size make them a risk. If swallowed whole, an almond can block a dog’s esophagus and lead to choking.
If you’re raising a dog in a family environment, then it’s vital that you educate your children or partner on the basics of dog digestion. If you’re aligned with the kind of dietary regimen that aids healthy eating for your canine, then you’re far less likely to run into future dietary issues or worry about feeding your dog the wrong thing. For young children, the temptation to slip their dog some nibbles from the dining table can be overwhelming. Proactive education regarding animal digestion could stop them from making a devastating error.
So, if your whole family understands the dog digestive system, you can trust them to make an informed decision and keep your dog happy and healthy.
Reviewed by Dan Richardson, Veterinarian
Dan Richardson has been a practicing veterinarian for over 10 years. He specializes in surgery and orthopedics. Dan is originally from rural western Nevada and attended the University of Idaho for undergraduate study and Oregon State University for Veterinary School. The Richardson Family enjoys camping and spending time on the water fishing, paddle boarding, or digging their feet in the sand somewhere warm.
- Mendel, L. Yale University. Is the Saliva of a Dog Amylolytically Active. (1907). http://www.jbc.org/content/3/2/135.full.pdf
- FDA. Manufacture and Labeling of Raw Meat Food for Companion and Captive Non-companion Carnivores and Omnivores. https://www.fda.gov/media/70183/download
- Burke, A. American Kennel Club. Best Foods for Dogs with Sensitive Stomachs.
https://www.akc.org/expert-advice/nutrition/best-food-for-dogs-with-sensitive-stomachs/ – ‘
- Sanderson, S. MSD Manual. Dog and Cat Foods. https://www.msdvetmanual.com/management-and-nutrition/nutrition-small-animals/dog-and-cat-foods
- American Kennel Club. Human Foods Dogs Can and Can’t Eat. (2019). https://www.akc.org/expert-advice/nutrition/human-foods-dogs-can-and-cant-eat/