What is unique about a dogs digestive system?

Ever seen your dog swallow a piece of food whole, or eat something that would make you sick? Here’s a break-down on how they digest their food.

Table of Contents Show

Open wide for entry
Next stop: Into the stomach
Small intestine: A long and winding tube
Nearing the journey’s end
When digestion runs off “tract”

Human jaw- can move up and down side to side and in a rounded motion. Teeth are designed for grinding having a flatter surface.

Dog jaw- can only move up and down. The teeth are designed to crush dense objects, having a three root system and are solid and sharp.

Human- used for breaking down food and lubricating digestion.

Dog- also used for lubricating food but they lack the enzymes to break down food. Instead their saliva contains enzymes that kill off bacteria. If you've ever seen your dog eat something old and gross and not get sick? Now you know why.

Humans- helps keep food from entering the wind pipe and designed for food to stay in our stomachs

Dogs- Good gag reflex. Even though dogs cannot chew up their food before it goes down the throat, it must still be the right size and amount to fit. If not, the dog simply throws up! Your dog is not sick. It's just his body telling him to try again. I know it's gross but completely natural.

Humans- food takes about one hour to move through our stomach, but depending on the amount and complexity sometimes longer.

Dogs- this is where most of their ability to break down foods take place. Their stomach is more acidic so it can break down large pieces of meat and bone. Food is kept in the stomach for a longer period of time, allowing the acid to break down animal proteins, bones, and fats. This explains why dogs can live with being fed only once or twice a day. They feel full longer because the food remains in their stomach longer.

Humans- where absorption of food takes place, the human intestinal tract is a lot longer than a dogs and therefore the body has more time to absorb nutrients from more complex foods such as plant and grain based foods.

Dogs-Digestive tract is a lot smaller. This means the dogs have less time to absorb nutrients from their food. This is why dogs do better on foods that are easily broken down such as meats bones and organs. But can struggle on complex foods such as plants and grains. This also means that bacteria have less time to multiply and cause problems. Ever seen your dog eat poop? Yes very gross, but plant based nutrients found in poo have been pre-digested making it a very convenient meal for our canine friend.

Unless your dog develops a sensitive stomach or other digestive disorder, you probably don’t give their digestive system much thought. In fact, your interactions with your dog’s digestion are most likely limited to what occurs before and after — or what goes in and comes out — which is typical for most dog parents. If you’re curious about what goes on during digestion, read on for a brief overview.

Open wide for entry

Digestion actually starts in the mouth, where food is cut, chewed and crushed into small pieces and mixed with saliva before it’s swallowed. At least in theory, that’s how the mouth and teeth work, although many dogs swallow their kibble whole — similar to how a vacuum sucks up dirt. Unlike human saliva, canine saliva doesn’t contain amylase, an enzyme that begins to break down the carbohydrates in food into sugars. The function of saliva in dogs is to lubricate food for swallowing.

Next stop: Into the stomach

Swallowing pushes food into the esophagus, a muscular tube that carries food from the back of the mouth to the stomach. No significant digestion or absorption occurs in the esophagus.

Dogs have a simple stomach that is essentially a large, muscular sac lined with a variety of glands.

Not only does mechanical digestion of food occur in the stomach, but protein digestion begins. Cells in the stomach wall secrete several substances that are important to digestion, including hydrochloric acid, protein-digesting enzymes, mucus and a hormone called gastrin. Gastrin signals glands in the stomach wall to release hydrochloric acid (aka stomach acid). Hydrochloric acid interacts with pepsinogen, the precursor to pepsin, the major enzyme responsible for breaking down proteins into smaller pieces.

Stomach contents become very acidic as a result of the hydrochloric acid that’s secreted. So to protect the lining of the stomach wall, other glands of the stomach secrete mucus and bicarbonate (similar to what’s found in baking soda). Not only do mucus and bicarbonate protect the stomach lining from acid, they protect it from being digested by the body’s own enzymes.

Food is mixed in the stomach until it becomes an acidic liquid called chyme, which then passes into the small intestine.

Small intestine: A long and winding tube

The small intestine, which is divided into three segments, is where most digestion and nutrient absorption occurs. It’s in the first part that enzymes from the pancreas are added to the chyme. Pancreatic “juice” contains digestive enzymes including amylase, five different protein-digesting enzymes and lipases, which break down fats. It also has sodium bicarbonate, which neutralizes the acidic chyme arriving in the small intestine so that the digestive enzymes have an optimal environment in which to work.

Bile, which is made in the liver, is also released into the small intestine. It contains salts that act like detergents when they combine with fat droplets. These tiny globs make it easier for lipases to do their job and make fats water soluble.

Normally, the intestines are always functioning, moving and mixing contents to ensure the digestive enzymes released into it are mixed well with the chyme. The churning movements of the intestine also bring digested material into contact with the surface of the intestinal wall where additional enzymes are added and nutrients are absorbed. Nutrient absorption takes place along the entire length of the small intestine.

Nearing the journey’s end

The last segment of the digestive system is the large intestine, which is made up of the cecum, colon and rectum. By the time the food that’s been eaten arrives here, most of the nutrients have been digested and absorbed. The primary functions of the large intestine are to absorb water and electrolytes and to transform what remains into a more solid form.

The colon is also where bacteria ferment fiber from food. While some products of bacterial fermentation are used as nutrients for intestinal cells, the process is also responsible for the production of gas, often associated with flatulence.

Feces, the end product of food digestion, are stored in the rectum prior to defecation. And, if digestion has proceeded normally, your dog will have their bowel movement outside your home.

When digestion runs off “tract”

As every pet parent knows, digestive processes can sometimes go a bit haywire. Intermittent loose stools or diarrhea, occasional vomiting and excessive, room-clearing gas are all signs that something’s not right with your dog’s digestive system. It may be a “sensitive stomach,” an inability to tolerate something that was recently eaten or an actual food allergy. Whatever the underlying cause may be, you’ll want your veterinarian to examine your dog if they experience these signs. Vomiting, diarrhea and excessive gas can indicate a potentially serious health condition. But it’s also possible that switching your dog to a food that’s specially formulated for dogs with sensitive stomachs, such as Diamond CARE Sensitive Stomach Formula for Adult Dogs, is all that’s needed. Be sure to ask your veterinarian to help you determine what type of food would be best for your dog.

RELATED POST: When Should You Worry About Doggy Diarrhea

RELATED POST: Things to Consider When Evaluating Dog Foods for Sensitive Stomachs

By Dr. Danielle Bernal
4/29/2021

You may only think about your dog or cat’s digestive system when something is wrong. Maybe they’re vomiting or have a sensitivity to a certain food. But understanding what makes your pet’s digestive system unique will help you better anticipate their health needs. Plus, some of these facts make for great conversation starters!

A dog’s digestive tract is about 6 times his body length and a meal typically takes 7-10 hours to pass through his body. That’s why it’s important to provide high quality nutrition that helps promote a healthy digestive tract.

Cats love to groom and as they lick their coat, big wads of hair get swallowed and form hairballs. Hairballs can obstruct the flow of food and in extreme cases may require surgical removal, or if you’re lucky, just some puke all over your nice new rug.

A dog’s jaw can only move up and down unlike a human jaw that can move up and down, side-to-side and in a rounded motion.

Cat and dog teeth are designed to rip, shred and crush dense objects consistent with their wolf and wild cat-like ancestors. Your dog uses his front teeth to grab food and then pulls his food to the back of the mouth where molars grind up the food into smaller chunks.

Some large, deep-chested dogs like Great Danes can suffer a potential fatal upset called bloat, because they cannot burp. Often seen when these dogs eat too quickly, their stomach becomes enlarged with both food and air. Treatment for these issues requires urgent veterinary attention.

Dogs have more teeth than humans and cats, (dogs have 42, cats have 30 and humans have 32).

When it comes to saliva, unlike humans, dogs lack the enzymes in their saliva that start breaking down food making that extra drool simply a great way to lubricate their food.

Dogs and cats have a good gag reflex so if they have eaten something spoiled or otherwise unsuitable, they can vomit rather easily.

Compared to humans, dogs generally keep food in their stomach for longer periods of time (4 to 12 hours), and have more acidic stomachs. This combination helps dogs break down large pieces of meat and bones into an easier-to-digest mush.

A dog’s stomach can expand to extraordinary sizes. Whilst this was a necessary trait for our dog’s wolf ancestor who lived a life of feast and famine, it today can be why if given a chance, dogs can eat extremely large quantities of food. Note – today with a steady supply of high-quality nutrition, your dog should never need to use this incredible function of his digestive system.

Dogs and cats have a relatively smaller digestive tract as compared to humans. That's why it's important to feed highly-digestible nutrition focused on intestinal health. It's also why you may see complex foods like full blades of grass appear in your dog’s poop. Their digestive system simply can't break down items like a sheep or other herbivore can.

Cholesterol may be important for us humans to keep track of, but it has no impact on your pet’s health.

Approximately 10% of all veterinary visits are the results of some gastrointestinal disease, with diarrhea being one of the most frequent clinical signs.

Dogs have 1/6 as many taste buds as humans have, (1,700 vs. 9,000) so the scent of their food determines whether they will eat it. In fact, dogs have up to 300 million olfactory receptors in their noses, compared to about 6 million in humans. And the part of a dog's brain devoted to analyzing smells is 40 times greater than ours!

Bad doggy breath isn’t normal or unavoidable! It’s actually a sign of dental or other health problems. Have your dog’s teeth examined by a veterinarian yearly and add a dental chew into their daily dental care.

As gross as it may be, it’s not abnormal for dogs to eat feces. The ASPCA say this behavior stems from their pre-domestication days thousands of years ago. Best tip here is to keep that backyard clean!

We believe that good digestive health is the key to unlocking your pet’s happiness, and it starts with what is in their bowl. With highly digestible recipes, Wellness CORE Digestive Health for dogs and cats promotes optimal nutrient absorption while optimizing a healthy digestive tract because with Wellness, a lifetime of wellbeing starts from within.

Cat Dog Health & Nutrition Digestive Health 4/29/2021

Dr. Bernal has over a decade of experience in veterinary medicine, specializing in animal nutrition. In her role as on-staff veterinarian with Wellness Pet Food, she educates pet parents on the importance of natural ingredients like wholesome meats and nutrient-rich superfoods. She passionately believes that proper nutrition helps pets lead happier, healthier lives. Dr. Bernal has been featured in radio, TV and print stories in numerous countries.

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