Diarrhea in Dogs

Written by Small Door's medical experts

Diarrhea in dogs—commonly defined as loose, watery, or runny stool—has a wide range of possible causes. Some of the diseases or conditions that produce diarrhea are mild, while others are more serious.

In This Article

What is diarrhea in dogs?

Diarrhea refers to any stool that is not firm and fully formed. It can range from being a bit loose, to runny and watery. 

Just like humans, dogs will occasionally have diarrhea. A single episode is typically not something to worry about, as long as your dog is otherwise feeling well. However, if your dog has several episodes of diarrhea in a short period of time or has chronic diarrhea, it is time to call your veterinarian. Frequent diarrhea will result in a loss of electrolytes and dehydration. This is dangerous for all dogs, but especially for puppies, elderly dogs, or immunocompromised dogs. 

Please note: If your puppy is less than 9 months old and is suffering from diarrhea, please take them to your veterinarian right away.

Knowing what to do when your dog develops diarrhea can make a big difference in their recovery.

Should you be worried about your dog’s diarrhea?

Diarrhea on its own is not a huge cause for concern, but if your dog has diarrhea in addition to other symptoms like decreased energy, fever, dehydration, or vomiting, it could indicate a more serious problem. 

When to contact the vet

Contact your veterinarian if your dog experiences any of the following:

  • Several bouts of diarrhea within 1-2 days

  • Red blood in feces

  • Mucus in feces

  • Vomiting

  • Extreme fatigue

  • Signs of pain, such as whining

  • If your  puppy is younger than 9 months old

A short bout of diarrhea that resolves itself quickly is normal, but if the diarrhea continues, or if you notice any other concerning signs, you should contact your veterinarian. Make note of how many episodes of diarrhea your dog has experienced, the color and consistency of their stool, and any other symptoms. This information will assist your vet in pinpointing the diarrhea’s cause.

Diarrhea symptoms in dogs

Making notes and being able to describe your dog’s condition thoroughly will help you and your veterinarian find a solution as quickly as possible. While it may seem unpleasant to examine your dog’s feces, stool provides valuable clues about your dog’s health. Here are some symptoms and descriptions you may want to refer to when speaking with your vet:

  • Loose, liquid stool

  • Watery stool

  • Bloody diarrhea

  • Frequent bouts of diarrhea

  • Bile in diarrhea

  • Mucus in diarrhea

Diarrhea can indicate a more serious illness if it appears alongside any of the following symptoms:

  • Appetite loss

  • Abdominal discomfort

  • Vomiting

  • Dehydration

  • Fever

  • Pain

  • Low energy

  • Weakness

Bloody diarrhea, whether the blood is bright red or black and tarry, is always cause for concern. Red blood in the stool, or hematochezia, is usually due to bleeding or irritation lower down in the intestinal tract. Black, tarry stool, or melena, is often due to bleeding in the stomach or upper small intestines. If you see blood of any kind in your dog’s stool, call your vet immediately.

What causes diarrhea in dogs?

The most common causes of diarrhea in dogs are eating something toxic, rapid change in diet, a food allergy, reaction to medication, or eating too many fatty or greasy table scraps. While your dog’s diet is the most likely culprit for diarrhea, there are many potential causes of diarrhea in dogs. 

Here are some of the categories:

  • Viral

  • Bacterial

  • Intestinal disorders

  • Cancer

  • Immune disorders

  • Toxicity

  • Diet

  • Environment

  • Parasites

  • Stress

Viruses and bacteria

Diarrhea is a symptom of many viruses and bacteria. In puppies, perhaps the most dangerous viral agent is the parvovirus, which is known for producing copious amounts of diarrhea. Distemper, herpesvirus, coronavirus, rotavirus, and other viruses can also cause diarrhea. Bacteria, like Clostridium, salmonella, and campylobacter, often lead to diarrhea as well.

Intestinal disorders

Intestinal disorders commonly share diarrhea as a symptom. Malabsorption, colitis, hemorrhagic gastroenteritis, and inflammatory bowel disease can all cause diarrhea. Some forms of cancer may lead to conditions that create diarrhea, as can some autoimmune disorders.

Dietary issues

Diet can certainly be a cause of stomach issues, especially if you have suddenly switched your dog to a new diet. This is why gradually introducing new dog food by mixing it with the old is important. Consumption of toxic substances, such as garbage, salt water, or certain human foods, causes diarrhea in many cases. Occasionally, environmental factors like stress can also cause watery stools.


Many intestinal parasites cause diarrhea. Protozoa cause diseases like giardiasis, coccidiosis, and amebiasis, while intestinal parasites like roundworms, hookworms, whipworms, and tapeworms also cause diarrhea.

Diagnosing diarrhea in dogs

Of course, it’s not hard to tell when your dog has diarrhea—but diagnosing its cause requires you to give your veterinarian some information. Vets diagnose diarrhea in dogs based on medical history, the owner’s description of symptoms, a physical exam, blood work, and diagnostic tests like fecal exams (for parasites), radiographs, ultrasounds, and anything else they deem necessary based on your particular dog’s situation.

Getting detailed information from the owner is especially important for cases where a toxin or foreign substance may have been consumed. Knowing that a dog had access to a potentially dangerous substance can save time—and the dog’s life.

Questions your vet will likely ask

If a visit to your veterinarian is needed, they will ask you several questions about your dog’s diet and activity. Jot down notes about the following to share with your vet so they have the most accurate information.

  • How long has your dog had diarrhea?

  • How frequent is the diarrhea?

  • What color is the diarrhea? Is there any blood in it?

  • What does the diarrhea look like?

  • Are they straining?

  • Is your dog on any medications?

  • Are they still active, bright and alert?

  • Are they still eating?

  • What is your dog’s typical diet?

  • Have there been any dietary changes in the last week, such as a change in food brand or flavor, people food, new treats or chews, scavenging in the garbage?

  • Is there a chance they may have swallowed something they shouldn’t have, such as a sock or something toxic?

Dog diarrhea treatment

The treatment for diarrhea in dogs will depend on the cause. In some cases, hospitalization may be required. Other cases may call for antiparasitic medications or antibiotics. Medications designed specifically to treat diarrhea in dogs do exist. Activated charcoal helps absorb some of the toxins that cause diarrhea, while motility-modifying medications like anticholinergic drugs and opiates slow down your dog’s motility, reducing the urgency of the diarrhea and helping to reduce dehydration. (However, the use of activated charcoal or narcotics to control diarrhea in dogs is quite uncommon.)

In other cases, your vet may need to treat your dog for underlying bacterial, viral, or parasitic infections. Sometimes it may simply be a matter of adjusting your dog’s diet.

The most important thing you can do to stop your dog’s diarrhea is contact your veterinarian. Many of the potential causes of diarrhea in dogs are serious and require veterinary care and prescription medications to treat.

Dog diarrhea home remedies

If your dog is suffering from mild diarrhea with no other concerning signs, you can try these home remedies to help them recover.


Diarrhea can lead to dehydration, so be sure to give your dog plenty of water. 

Bed rest

Just like humans, getting plenty of rest helps the body heal. Keep your dog in a quiet part of the home – somewhere with hard flooring may make it easier to clean up any accidents.

Over-the-counter anti-diarrheal medicine

It may be tempting to give your dog diarrhea medicine, but depending on the cause of their diarrhea, it could make the situation worse. Diarrhea is the body’s natural process of flushing out toxins or bacteria. Anti-diarrhea medicine causes constipation, and would prevent these toxins or bacteria from being expelled.

In addition, if given at the wrong dosage, anti-diarrhea medicine can be toxic for your dog. Check with your veterinarian before giving your dog any anti-diarrheal medicine to make sure it’s safe for your dog, and to confirm the correct dosage


If your dog’s diarrhea is the result of eating out of the garbage, or ingesting food that upset their stomach, fasting can help their stomach reset. Stop feeding your dog for 12 hours to clear their stomach out, and then put them on a temporary diet of the bland foods listed below. Be sure to give them plenty of water during their fast. 

Please note that a young puppy should never fast. If your puppy has diarrhea, take them to your veterinarian for advice.

What to feed dogs with diarrhea

You can calm your dog’s stomach and digestive system by feeding them bland foods. Instead of their regular dog food,feed them a small portion of any of the following until the diarrhea subsides and they start to feel better.

  • Plain white rice or pasta

  • Plain oatmeal

  • Canned pumpkin

  • Skinless boiled chicken

  • Boiled potatoes (without the skin)

If these home remedies don’t help, or your dog’s condition worsens, contact your veterinarian right away.

Is there a cure for diarrhea in dogs?

In most cases, diarrhea is a problem that will go away on its own, or can be resolved by consulting your veterinarian. However, there’s no permanent “cure” that will prevent your dog from ever having diarrhea again.

Is diarrhea in dogs contagious for humans or other pets?

Some causes of diarrhea in dogs may be contagious to other dogs; if you have other dogs in the household, ask your veterinarian about the possibility of contagion.

There are a few causes of diarrhea that are potentially transmissible to humans, such as giardia; however, it’s extremely unlikely that people in the household will contract the cause of your dog’s diarrhea. But of course, it’s always smart to maintain good hygiene around any animal that is sick.

What is the cost for treating diarrhea in dogs?

The cost of treatment for diarrhea in dogs will include a vet visit, but can vary after that depending on how many tests are needed to diagnose the cause. (If your vet can pinpoint a reason simply by talking to you, a diagnosis may require fewer tests.) You may incur additional fees if medications and follow-up visits are necessary.

In the most serious cases, hospitalization and supportive care will be necessary. These will add significantly to the costs.

Recovery and management of diarrhea in dogs

The time it takes for your dog to recover from their diarrhea will vary. If the cause is serious, hospitalization and supportive care may be necessary. In mild cases, the diarrhea might clear up in as little as several hours. Your veterinarian will provide you with medication if they feel it is required.

Once you’re back home, be ready to take your dog out to relieve himself at a moment’s notice. Make arrangements for your dog to be monitored and taken out frequently if you will not be home, and consider crating your dog without bedding for easier clean up.

Bear in mind that some causes of chronic diarrhea, like diarrhea caused by a food allergy or intolerance, will take patience on your part as you take measures like experimenting with elimination diets to narrow down and identify which food was causing your dog’s diarrhea.

How Long Does Dog Diarrhea Last?

The duration of your dog’s diarrhea may vary depending on the cause. Most cases caused by mild stomach upset will clear up in a few days. If your dog is suffering from persistent diarrhea, contact your veterinarian.

Preventing diarrhea in dogs

Some cases of diarrhea are preventable. Vaccinations exist for viral conditions like distemper and parvovirus. Preventing your dog from consuming toxic substances like garbage, salt water, and human food can reduce their risk of diarrhea from toxicity and indigestion. Keeping your dog up to date on parasite prevention will help reduce the risks of parasites, too.

Other causes of diarrhea, like cancer, immune conditions, or bacterial infections may not be preventable. In these cases, early intervention at the first sign of infection is the best way to prevent major complications.

Summary of diarrhea in dogs

While a single episode of diarrhea in dogs is usually not cause for concern, repeated episodes should always be investigated by a veterinarian, to diagnose and treat the underlying cause, and ensure your dog doesn’t suffer from dehydration. If caught early (and depending on the root cause), diarrhea is usually treatable and dogs will recover well.

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