Why the Dog Digestive System is the Key to a Healthy Dog

It’s been said that “the key to a man’s heart is through his stomach.” Well, the same can be said for dogs.  The gastrointestinal tract is the key to all organ systems, not just the heart, performing at their finest. The digestive system does more than just produce poop, it feeds the body, supplying nutrients like glucose and amino acids, to all cells and systems. Your dog’s heart wouldn’t beat, their tails wouldn’t wag, and their tongue wouldn’t loll without it. So, what does that all mean? It means the better that you feed that digestive system, the better your dog will function. Providing high quality nutrition directly impacts the quality health in your pup.

Let’s take a quick journey through a dog’s digestive system in order to better understand where the food that we’re feeding helps or hinders their health, performance, and even happiness.

The Anatomy of a Dog’s Digestive System

At its most basic, a dog’s digestive system is one long, continuous tube that starts at the mouth and ends at the anus. However, what the digestive system does is anything but basic. Each part has its own specific functions with the end goal of breaking food down into digestible pieces that are absorbed into the bloodstream and taken to various parts of the body.

  1. Mouth and esophagus: Your dog’s teeth are for more than providing that adorable smile. Rather, they’re the first step in the digestive process. They take those large food bits and break them down into easier-to-swallow morsels. With the lubricative aid of saliva, these bits travel down the muscular esophagus into the stomach.
  2. Stomach: The harsh environment in the stomach is where the enzymatic digestion begins. The stomach is thick-walled in order to protect itself from the acidic gastric juices that start the breakdown of food (A dog’s stomach can reach a pH of 1.5, an acidity that’s capable of dissolving bone!). Food stays in your dog’s stomach for four to eight hours, where it’s constantly mixed with the gastric juices before it heads to the small intestine.
  3. Small intestine: Broken into three segments, the duodenum, ileum, and jejunum, the small intestine is the site of further digestive breakdown. The liver and pancreas secrete bile and other digestive enzymes respectively into the duodenum in order to break down fat, proteins, and carbohydrates and to neutralize the acidity of the food. The small intestine is lined with millions of finger-like projections called villi. These villi are responsible for moving these nutrient end products into the blood stream. From here, those nutrients, like glucose, travel to the brain, the eyes, the heart, the kidneys, everywhere, even to your dog’s tiniest toe, in order to provide every cell with the products they need to work, grow, and divide. If a dog’s diet doesn’t provide these important nutrients, these cells won’t function properly. What isn’t absorbed here moves into the large intestine.
  1. Large intestine: The large intestine, or colon, is mainly responsible for fluid absorption and storage. The colon is also home to your dog’s gut microbiome, the coveted bacteria that work to extract every last viable nutrient before this ‘food’ leaves the body. These gut bugs also produce key vitamins as byproducts of this digestion and help bolster your dog’s immune system by producing important antibodies to ward off common infections. This is where probiotics come in. Giving your dog probiotics can help populate a gut with ‘good’ bacteria and to support those already living there in order to keep digestion working smoothly and efficiently.

Once your dog’s large intestine has gleaned all the nutrition and fluid that it can from the food that they ate, it moves through the end region called the rectum and through the anus into the world as poop. If you’re unhappy with your dog’s poop, try upping their fiber. Fiber is almost a miracle food as it works to alleviate both watery poop and constipation by firming up bowel movements. 

Dog Digestive System Process

If you’ve ever wondered why your dog’s propensity to poop is much more frequent that your own, it’s because food moves through their digestive system much more quickly. While food may sit four to eight hours in the stomach, compared to 30 minutes in humans, it takes only a couple of hours to move through the intestines, compared to our 20-30 hours in us. This is also why your pup is more willing to settle for once or twice a day feeding and you may crave constant snacks.

The proof is in the poop. Your dog’s poop is like a storybook about their digestive tract. Any variation in color, texture, frequency, or scent can alert you of any gut troubles. Getting familiar with your dog’s poop isn’t gross, it should be seen more as a way of helping out your best friend.


The gastrointestinal tract is really where it’s going on in your dog’s body. It is what turns dog food into a walk in the park, a game of fetch, a healthy heartbeat and a fresh pile of poop. What you feed your dog’s GI will determine how efficient and smoothly this system works, and how healthy and happy your dog feels for years to come.

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