How much time do you spend thinking about your dog’s stomach? If your answer is “not a lot,” you’re not alone. With so many pet parent responsibilities to take care of, it’s no surprise that what goes on in your dog’s stomach isn’t at the top of your mind.
If you do happen to think about your dog’s tummy, though, you may wonder what exactly goes on in there (and, admittedly, hope that what’s in there doesn’t come back up).
The canine stomach plays a crucial role in the early stages of digestion. Plus, a healthy tummy is often an indicator of good overall health.
The more you understand your dog’s stomach, the better you can spot when your dog has a digestive problem and help them feel better.
Dog Stomach Location and Size
So, where is a dog’s stomach? It is in the abdomen. The top of the stomach is connected to the bottom of the esophagus, and the bottom is connected to the small intestine.
The stomach is a J-shaped sac and has several layers of muscle to do the hard work of grinding food (more on that later). Its size varies depending on a dog’s size: a Chihuahua’s stomach will be much smaller than a Rottweiler’s.
A dog’s stomach contains numerous inner folds that allow it to expand far beyond its original size after eating. Evolutionarily, these folds served an essential purpose when wild dogs went for long stretches without eating and needed energy to sustain them until their next meal. The more food the stomach could hold, the more energy a dog could have for hours.
Parts of a Dog’s Stomach
Now, let’s talk about the stomach anatomy of a dog. A dog’s stomach is divided into three parts:
- The fundus
- The body
- The pyloric antrum
The fundus is the top part of the stomach, near the esophagus. The body is the large, middle part of the stomach. The pyloric antrum is the bottom of the stomach and leads toward the pyloric sphincter, the ring of muscle that connects the stomach to the small intestine.
The inside of a dog’s stomach contains gastric folds that allow the stomach to expand after a meal. This inner layer also contains cells that produce substances like stomach acid, mucus, and enzymes.
The stomach lining comprises several layers of smooth muscle, plus an extra layer of muscle that helps the stomach grind and mix food.
The Stomach’s Role in Dog Digestion
A dog’s digestive system is responsible for breaking down food, absorbing nutrients, and packaging the rest as solid waste to be eliminated.
After food travels down the esophagus and enters the stomach, the stomach gets to work. It plays several key roles in early digestion: short-term food storage, grinding down food, and releasing food into the small intestine. Let’s explain each role in detail.
Short-Term Food Storage
A dog’s stomach can hold food for anywhere from 4 to 12 hours, allowing dogs to use the energy from that food until their next meal. Even if your dog scarfs down their food, it will stay in the stomach for a while.
Grinding
The stomach grinds dog food down into a liquid substance called chyme. Grinding is hard work that requires enzymes and stomach acid (hydrochloric acid). These enzymes, called proteases, break down protein in the food.
Hydrochloric acid has a very low pH of 2, which is highly acidic. It helps activate the proteases and prevent harmful bacteria or other microorganisms in the food from upsetting a dog’s stomach.
Hormones control the grinding process. Gastrin, a stomach hormone, activates the stomach cells to release hydrochloric acid.
Muscles in a dog’s stomach work in a coordinated fashion to produce wave-like contractions — peristalsis — to move the food around in the stomach, grinding and mixing it into chyme.
Release of Food Into the Small Intestine
After the food has turned into chyme, peristalsis pushes the chyme toward and through the pyloric sphincter and into the small intestine. Not all of the chyme leaves the stomach at once. It is released in small amounts.
Interestingly, the stomach is not where nutrient absorption takes place. Nutrients are not absorbed until the chyme reaches the small intestine.
How Should a Dog’s Stomach Look and Feel?
If you want to feel your dog’s tummy, place your hands on your dog’s belly, just behind the ribs. The stomach should feel soft, with no lumps or masses. If your dog has just eaten, their tummy will be slightly bigger, which is normal.
Your dog’s stomach should not feel hard or tense. Also, the abdomen should not be tender. In other words, your dog shouldn’t feel pain when you touch their belly.
Although you won’t see this from the outside, your dog’s stomach should be pink and smooth, with no areas of redness or irritation. Areas of redness could indicate inflammation or bleeding.
How Should a Dog’s Stomach Sound?
With all of the work that a dog’s stomach is doing, it’s not surprising that the stomach makes noises that are loud enough for you to hear.
A few common noises are from the sounds of digestion and hunger. The sounds of digestion are called borborygmi, essentially the sounds of peristalsis. If your dog is hungry, their stomach will growl loudly because peristalsis is still taking place without any food in the stomach.
The stomach may also make sounds if there’s something wrong, such as diarrhea and gas.
4 Common Stomach Issues in Dogs
Tummy troubles are among the most common reasons dogs go to the vet. Here are some common stomach problems in dogs:
Gastritis
Gastritis is inflammation of the stomach lining. It can be caused by many things, such as eating spoiled food or table scraps. Dogs with gastritis often experience vomiting and reduced appetite. Fortunately, gastritis usually resolves on its own within about 24 hours with supportive care. This includes withholding food for 24 hours and reintroducing food (bland food diet), provided there’s no more vomiting.
Bloat (Gastric Dilatation and Volvulus)
Bloat is a life-threatening medical emergency in dogs. It occurs when the stomach fills with gas and twists on itself, compromising blood flow throughout the body. Large, deep-chested dogs like Dobermans are prone to bloat. This condition must be treated immediately to reduce pressure on the stomach wall and other organs.
Stomach Ulcers
Stomach ulcers occur when the hydrochloric acid in the stomach damages the stomach’s inner lining. Usually, mucus produced by stomach cells coats the lining, protecting it from the extreme acidity. However, if that protective mucosal layer is damaged, the acid reaches the inner lining and causes irritation and inflammation.
Stomach ulcers may be mild or so severe that they perforate (make a hole) through the stomach wall. Treatment includes treating the underlying cause and helping the mucosal lining heal and repair.
Gas
Dogs do their fair share of passing gas. Gas is frequently caused by either dietary changes or dietary indiscretion. Dogs may have some abdominal discomfort and loud stomach noises along with gas. It is typically treated with dietary changes, including lower fat and fiber content.
Tips for Supporting Your Dog’s Stomach & Digestive Health
If your dog has ever had tummy issues, you know it can be a messy and smelly affair. The more you can do to keep your dog’s stomach happy, the better. Here are some tips to support your dog’s healthy digestion:
Feed a complete, balanced diet. A complete and balanced diet will provide your dog with the nutrients they need, in the appropriate proportion, for their life stage. Look for the ‘nutritional adequacy statement’ by the Association of American Feed Control Officials (AAFCO) on the label to be sure that food is complete and balanced.
Avoid excessive table scraps. Table scraps are delicious morsels that can wreak havoc on your dog’s digestive system. These scraps can be high in fat and highly seasoned and will not be digested well by your dog. This can result in stomach upset and symptoms like abdominal pain, vomiting, and diarrhea. Resist the temptation to feed your dog anything from your plate.
Block access to garbage cans and harmful substances. Dogs are not known to be picky eaters. They’ll happily sift through the trash and munch on things they’re not supposed to, even toxins like antifreeze! Keep harmful substances well out of reach of your dog and make your garbage can as inaccessible as possible.
Switch food gradually. Switching to a new dog food too quickly doesn’t give your dog’s digestive system time to adjust. This can lead to tummy upset and digestive problems. Transition to the new diet over several days to a week, slowly mixing in more of the new one into the old one until your dog is eating only the new one. Monitor your dog’s response to the new diet and transition even more slowly if necessary.
Keep your dog up to date on parasite prevention. Intestinal parasites like roundworms and hookworms cause many issues in the digestive system, such as malabsorption and intestinal bleeding. Keep your dog on a monthly dewormer that your veterinarian prescribes.
Supervise your dog with chew toys. Dogs can be enthusiastic with their chew toys…sometimes too enthusiastic. They might break off and swallow a piece of their chew toy that could become lodged in their stomach or small intestine, causing major digestive issues. If your dog likes chew toys, select durable toys that do not contain small parts that can be chewed off, like beady eyes and noses.
Adjust your dog’s feeding habits. Dogs that eat quickly or eat large amounts at once can run into digestive problems at mealtime. Eating more slowly decreases the chances of swallowing air and developing bloat, making slow-feeder bowls a great choice for dogs that scarf down their food.
Smaller meals keep food in the stomach more consistently throughout the day, decreasing the likelihood of nausea due to stomach acid churning in an empty stomach.
