Why does a diet change give my dog diarrhea? What is ‘dog garbage gut’? Is my dog eating grass because she’s sick? Fascinating information on how dogs digest their food and what’s up with their poop.


How Come Dogs Don’t Get Sick When They Eat Spoiled Food?

There are notable differences between the way dogs digest their food and the way we humans do. Firstly our mouths are built differently. The human jaw, teeth and saliva are designed to crush and break down food even before it is swallowed. On the flip side, dogs teeth are designed to rip, tear and pull. While humans swallow their food in well-mashed clumps mixed with spit; dogs swallow their food in barely-chewed chunks…the expression ‘wolfing it down’ comes to mind.  Dog saliva contains some enzymes to break down food, but its main purpose is to kill bacteria. That’s why dogs can dig up old bones (or worse dead animals!), chew on them, and not die of infection. Their spit is much better at killing germs than ours.

How Fast Can A Dog Digest Its Food?

It only takes about 9-12 hours for food to pass from the mouth of a dog, through their digestive system, and come out the other end. This ‘fast track’ limits the time that any bacteria can grow inside a dog’s gut. Compare this to the 24-hour transit time of humans. Powerful acids in the dog’s stomach (dog gastric acid is much stronger than the human version) quickly break down unchewed chunks of food and act as another buffer against harmful bacteria that would otherwise make a dog sick.

So Then Why Does My Dog Get Diarrhea When I Switch His Diet?

Like humans, dogs have healthy bacteria in their digestive system that helps them break down food. This flora of bacteria adjusts itself to the kinds of food a dog is used to eating. Sudden switches in food (like a trip to the garbage can for dinner) can catch these bacteria by surprise and inhibit their ability to facilitate digestion. The result? A poo puddle instead of a firm plop. In the veterinary world, we sometimes refer to these medical cases of dietary indiscretion as ‘garbage gut’. Interestingly, surprising the digestive track is a problem in many animals. Feeding corn to deer in the dead of winter can be disruptive enough to a deer’s digestive track to cause death. Farmers that move cows from a diet of dry hay to fresh green grass must also be careful to make the transition gradually, lest the cow get ill.

The Science of Diarrhea

31391338 - gastroenteritis or infectious diarrhea. gastroenteritis is an intestinal infection that causes vomiting cramping and diarrhea.

Many times, diarrhea is caused by inflammation of the bowel due to things like disease, parasites, allergies, dietary indiscretions, or conditions like irritable bowel syndrome. The ailing digestive track inflames, coats itself with mucous, and loses its ability to absorb water. The resulting stool can be loose and contain mucous and/or blood. Keep in mind that there are dozens of canine diseases that cause dogs to have diarrhea. That’s why it’s impossible for us to dispense medication or advice on the phone without doing a physical examination and ensuring that we understand why your dog is sick.

My Dog Is Eating Grass; Does That Mean She’s Sick?

57125697 - funny chihuahua enjoy chewing the summer grass. sunny day

No. There are many theories on why dogs eat grass: stress, natural instinct, an urge to vomit…perhaps they are all correct! Certainly wild dogs eat their fair share of vegetable matter. In the wild, dogs also consume grass when they consume the stomachs and intestines of herbivores. For all we know, grass may contain essential elements to a dog’s good health.


The Downside of Eating Grass

But if you own a dog that grazes on grass, keep this in mind. Many lawns are treated with weed and bug killers. While the grass probably won’t make your dog sick, the chemicals will. It’s best to pull your dog clear of any grass that may have been sprayed or treated.  For more on this topic, check out this Purdue Veterinary School Blog.

Dogs That Eat Grass Are At Risk for Parasites

Two of the most common intestinal parasites live out a part of their life cycle on the tips of green grass blades, just waiting for some foolish dog to walk by and gobble them up. Wild animals and other dogs infected with roundworms or hookworms poop in your yard, the eggs in the poop hatch on the soil surface, and the juvenile worms crawl up grass blades and wait for their next trip into a dog’s stomach. At Brookfield, 6% of all of our dog patients are infected with roundworms or hookworms.

This Center for Disease Control chart on the life cycle of a hookworm will raise your hairs.

If Diarrhea is Due To a Diet Change, Why Do I Need To See A Vet?

Several reasons. Firstly, diarrhea isn’t only caused by a change in diet. In a recent study conducted by Idexx Pet Laboratories, 15% of all dogs that went to see a vet for vomiting or diarrhea were infected with Giardia, an intestinal parasite that can also infect humans. Dogs that weigh less than 15 pounds that have diarrhea can die due to secondary complications like blood loss and dehydration. But let’s not dismiss that dogs experiencing diarrhea are uncomfortable and cleaning up diarrhea is a pain in the a…well it’s a problem!  Brookfield vets can diagnose why your dog has diarrhea and give your pet medication to make him or her feel more comfortable and stop having accidents in the home.


Use These Discounts for your Dog’s Parasite Prevention


So How Do I Know If My Dog’s Poop Is Healthy?

It’s a gross topic, but it’s worth reviewing. A dog’s stool should be well-formed and chocolate brown. Specks of blood or opaque slime (this is likely mucous) are not normal and require veterinary care. Wiggling grain-sized bits of white or gray/whitish spaghetti like strands are also not normal and require a visit to the vet. Dogs that are fed diets that contain dyes (orange and red are common in some kibbles) can pass stools that are colored similarly.

Care to explore a ‘poop chart’.  They actually exist!  This one is from our friends at Purina.  Brookfield carries prescription Purina diets.

Does It Matter if I Feed Wet Or Dry Food?

Contrary to popular belief, wet food doesn’t give your dog watery stools. Diarrhea or wetter-versus-drier stools are a function of how much water the dog’s digestive track is absorbing from the food as it transits through the dog’s gut. If your dog has firmer stools on a dry diet-versus-a wet diet, it’s likely due to the higher fiber content of dry foods, not the absence of water.

Still have some questions?  Reach out for more information!