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10 Interesting Facts About Your Dog’s Digestive System

Written by Anna Hollisey


puppies enjoying a yummy dinner

Our dogs are amazing! You already knew that… but did you know that their stomachs can store food ‘for later’? Here are 10 facts about your dog’s digestive system… see how many you didn’t already know. 

1. Dogs Are Built To Cope with Cholesterol 

Like humans, dogs need cholesterol to build body tissue. But did you know that cholesterol problems are quite rare in dogs?
That’s because our canine companions have evolved from die-hard hunters, so their bodies are designed to accommodate animal fat. When dogs ingest animal fat, it’s absorbed into the bloodstream from the small intestine and rapidly dissolved by the LPL enzyme. Most dogs will return to normal cholesterol levels 10-12 hours after eating something fatty. There are conditions which prevent this from happening (such as hyperlipidemia or diabetes, which limits the enzyme), but in general dogs don’t suffer from cholesterol build-up the way that humans do. 

2. Check That Poop…

If you don’t already monitor your dog’s poop, well, you should. Its color and texture provides a useful snapshot of your dog’s overall health! Here are some poop types to watch out for (and you can read more detail on this topic here/learn/dog-health/dog-poop-everything-you-need-to-know – as long as you’re not eating a slice of cake right now!). 

  • Runny poop? The occasional bout of diarrhea is normally caused by something strange your dog has eaten or stolen. If they’re otherwise healthy and recover quickly then you don’t need to worry – but if it continues or there’s blood then talk to your vet. 
  • Green poop? It’s a warning signal from the intestines (… or your dog might have eaten spinach). It can indicate bowel disease or infection. 
  • White poop? Your dog could be constipated – make sure they’re drinking lots of water and increase the fiber in their diet. If it continues then consult your vet.
  • Red poop? It can be as simple as a wound near the rectum, but it can be something more serious such as infection or intestinal problems. Blood in your dog’s poop calls for a swift visit to the vet. 
  • Purple? Nope. This one’s not a thing… your dog’s been eating the coloring pens again. 

3. Dogs Have Indigestion and Heartburn

Just because they don’t roll around moaning doesn’t mean our dogs don’t get funny tummies – just like us, their stomachs tell them when they’ve eaten too much, too fast, or too wrong. They get stomach pains like us, acid reflux and even heartburn. Sadly, we owners won’t always know about these pains – but keep an eye on your dog for post-food symptoms, because if they become regular, they can be treated. 

4. Dogs Can’t Chew 

Well, not in the human sense of the word. We know what you’re thinking. If they can’t chew, what are they doing to your favorite sneakers? They’re nibbling, biting and breaking it apart.

If you look at your dog’s teeth, you’ll see they are differently shaped than humans’ teeth. They are designed to cut, rip and break meat into pieces; their molars are not like ours, which have ridges for chewing. Dogs can’t move their jaws from side to side either. When they eat, they open and close their jaws on the food to break it up for swallowing, rather than softening and loosening it up the way people do. 

5. Diarrhea and Vomiting

Sorry but we’re back on poop. While diarrhea can simply be a sign that your dog ate something that disrupted their digestion, it’s sometimes a symptom of more serious health issues. It can be caused by worms, pancreatic, liver or kidney disease, poisoning, coronavirus, or even cancer. If your dog has D&V accompanied by any other symptoms OR lasting for longer than 48 hours, get them to the vet. 

6. Dogs have Fast Intestines

They’d win gold at the Digestive Olympics. Once food hits their small intestines, dogs can process it up to 5 times faster than humans! Not just because their stomachs are smaller: proportionally their small intestines are the same size as ours. It’s probably because dogs were once roving hunters who needed fast fuel. 

7. Dogs’ Stomachs Store Food 

Lots of dogs stash away treasure for later… meanwhile, their stomachs are busy doing the same thing! This is a really cool feat. If they are inactive, dogs are programmed to store some of their food in their stomachs for up to 12 hours. (Makes more sense than leaving it in the bowl, obviously.) When they’re ready to go out or work, that food will be moved along to the intestines to be turned into ready-to-go energy. 

8. Wheat and Grains are OK

Tempted to buy the premium grain-free version of your dog’s dinner? Unless your dog is gluten-intolerant, you might not need to. Carbs like wheat, potatoes, and grains of all kinds can be effectively digested by most dogs’ digestive systems. In fact, these starchy foods provide slow-release energy to fill them up and power your dog through their busy day.

9. How Dogs Can Eat Almost Anything

In just one day, a dog’s snacks could include a sock, a plastic bag, and a mouthful of animal poop. How come our dogs aren’t sick ALL THE TIME? We’ll tell you why: Their stomachs contain way more acid (possibly as much as 10x) than the human stomach does. That’s how they can handle bones, bags, and a revolting amount of germs and pathogens. The acid dissolves almost everything in its path. But we still can’t see the appeal of eating socks.

10. Vegetables are Pointless (sort of)

If our dogs would speak, they could tell us why they eat around the peas that we optimistically added to their dinner. Dogs just don’t need to eat their greens like we do. They’re built to cope without fiber: in fact they’ll probably just poop it out. While vegetables do provide useful vitamins and nutrients to our dogs, their fibrous texture is discarded inside the digestive system. (There’s an exception to this… If the vet says they have a problem with constipation, all bets are off.)