What Causes Dog Diarrhea?

Posted by Dr. Roth on

Sad dog face, what causes dog diarrhea?

While it’s not the most pleasant topic of conversation, pet parents with dogs have undoubtedly dealt with diarrhea at some point or another. It’s a common issue, but that doesn’t make it easier when it does occur. 

Dog diarrhea has many causes. Understanding them can help pet parents take steps to reduce the duration of the episode and limit the number of times a dog experiences diarrhea.  

How Dog Digestion Works‌

Dogs digest their food a bit differently than humans. For humans, digestion starts in the mouth. Saliva and chewing begin the process, which then continues in the stomach and intestines. Dogs don’t really chew their food, and instead swallow it in chunks. Their stomach acid breaks it down and digestion takes about ten hours from eating to the large intestine. 

What Causes Dog Diarrhea?

In cases of healthy digestion, the result is a well-formed stool. However, several issues can affect digestion, which can then cause diarrhea. Some of these issues are minor and clear up quickly. Others, however, are more serious and require immediate veterinary care. Some of the most common causes of diarrhea in dogs include:

Stress or Excitement

Sometimes, extreme stress or excitement causes digestive upset. Sudden changes in routine, moving, having a baby, events like thunderstorms or fireworks, and welcoming visitors can all affect a dog’s mental state. They can also affect digestion, leading to diarrhea. Usually, things go back to normal after a few days. 

Dietary Issues

It can take a dog several days to adapt to a new type or brand of dog food. Part of the process of adapting might involve temporary diarrhea. Dogs may develop diarrhea as a result of a food intolerance or allergy. They may also experience diarrhea if they eat too much garbage or spoiled food, an issue that can lead to what’s known as “garbage gut.”


Sometimes, antibiotics or other medications can mess with a dog’s digestive system, resulting in stomach upset and diarrhea. 


Parasites like roundworms, hookworms, and giardia can all affect digestion, making it harder for a dog’s body to absorb nutrients and water. Untreated, these parasites can lead to lethargy and dehydration. They most commonly affect puppies and adult dogs with weakened immune systems. 

Viral or Bacterial Infections

Infections of salmonella, E. coli, distemper, and parvovirus can all have devastating effects on dogs and puppies. Diarrhea is one of the most common symptoms of such infections, and pet parents are likely to notice other symptoms as well, including vomiting, lethargy, and changes in temperament. 

Eating Foreign Objects

Dogs are notorious for eating things they shouldn’t. They’ll get into the trash and swallow wrappers, eat the stuffing from their toys, or pick up rocks outside. These indigestible objects can obstruct the bowel, making it difficult for a dog to relieve himself. In addition to diarrhea, pet parents are also likely to notice straining to go, vomiting, and a loss of appetite. 

Ingesting Something Poisonous 

Again, dogs can get into things they shouldn’t, including dangerous chemicals and harmful plants. Eating such substances can cause a dog to become very ill. Consuming poisonous substances can cause diarrhea, vomiting, lethargy, loss of balance, or collapsing. 

Ways to Treat Dog Diarrhea

Changes to a dog’s bowel movements, including color, size, and consistency, can indicate a problem. It may be a minor issue, or it can be more serious. Pet parents should take note of what their dog’s stool looks like so they can describe it to a vet. 

There are a number of treatments for diarrhea and for improving a dog’s digestive health. These include temporary diet changes or using dog diarrhea supplements and other dog health care products. In many cases, pet parents can receive dog advice from their primary vet over the phone without having to make an appointment. In more serious cases, an office visit may be necessary. 

In minor cases of diarrhea, pet parents may be able to treat the issue at home. One method of managing digestive upset is by feeding the dog a diet of bland foods like rice, skinless chicken, cooked eggs, boiled potatoes without the skin, yogurt, and cottage cheese. Pet parents may also consider restoring digestive balance with probiotics for dogs

In more serious cases, pet parents may need veterinary care. A thorough examination can help get to the root of the problem and allow the vet to prescribe appropriate treatment. Depending on the cause, the dog may need antibiotics, IV fluids, deworming, or other supportive care. 

Questions or Concerns? Seek Professional Dog Health Advice

Diarrhea in dogs can indicate a number of different issues. While pet parents can treat minor digestive upset at home, more serious cases may require professional care. If a pet parent has any concerns about their dog’s bowel movements or they’ve noticed additional symptoms, they should seek advice right away.

Pet parents can get professional dog advice from an online vet. With Fuzzy’s 24/7 Live Vet Chat, they can speak with a vet almost instantly any time of day or night. They can discuss symptoms, get advice on the best probiotic for dogs, and more. Sign up to become a Fuzzy member today.‌

Medical Advice Wellness Care