Why Does My Dog Only Have Diarrhea At Night? [How To Help]

Diarrhea is not an uncommon thing and most dogs will suffer from it at least once in their life. But if it happens during your sleep, you might wonder, “why does my dog only have diarrhea at night?”

A common reason for night diarrhea is a change in diet. If the dog eats food it is allergic to, it will lead to diarrhea. An anxious and diseased dog will also have this problem. But there are a few more reasons for night diarrhea in dogs.

Why Does My Dog Only Have Diarrhea At Night?

There are many reasons why a dog might have diarrhea at night. This might be due to stress, allergies, medication, disease, or something else.

Stress And Anxiety

Dogs can get just as stressed as humans can. Changing homes or going on long travels can be stress-causing activities. Another common reason for stress is separation anxiety which affects dogs that get too attached to their owners. Dr. Debra Horwitz explains the symptoms of this condition as such:

They become extremely anxious and show distress behaviors such as vocalization, destruction, or house soiling when separated from the owners. Most dogs with separation anxiety try to remain close to their owners, follow them from room to room and rarely spend time outdoors alone.

Bringing home a new pet will also be stressful for some dogs. The dog can get scared due to loud noises during the night. If someone is setting fireworks outside they may scare the dog. In the end, all stressful situations will lead to physical symptoms like diarrhea.

Food Allergies

Don’t introduce new foods to a dog in the evening meal. If the dog ends up having pet food intolerance, you will be woken up by it suffering from diarrhea. The good thing is that you will instantly know the reasons and avoid the food in the future.

Allergies are an immune response to certain allergens found in many things including food. If the dog ate something else that could contain allergens, it also might cause diarrhea. Besides the dog having diarrhea at night, other signs of food allergy in dogs include vomiting, itching, and a rash.

Change Of Diet

Your dog doesn’t have to be allergic to the food it eats to get watery diarrhea. If it has been on the same diet for a long time, and recently you’ve changed it to something else, it may experience diarrhea.

The gut microbiome of the dog is used to getting the same food and digesting it. A change in the type of food, size, taste, or brand, will disrupt this microbiome and cause chronic diarrhea. This usually happens when changing from a puppy diet to an adult diet.

Bad Eating Habits

Besides food, dogs may eat something that isn’t meant for them to digest. This is also referred to as dietary indiscretion. You may find your dog eating from the garbage bin or the toilet. There are times when it even may start eating feces. Some dogs will also eat strings from rope toys, parts of furniture, or rocks.

Eating things like garbage will affect the dog’s digestive health and cause diarrhea. Veterinarians refer to this as “garbage toxicosis” or “garbage gut”.


Some medications may have diarrhea cited as a side effect. A dog dewormer is one of the common causes of dog diarrhea at night. That medication is used to help with parasitic infections in the intestines. Dogs might have diarrhea for a short while after taking the medication, but it will stop with time.

Besides dewormers, antibiotics are another common cause of diarrhea. These are medications prescribed for a bacterial infection. Other diarrhea-causing medications include anti-inflammatories, heart medicines, steroids, and cancer medication.

Health Problems

Loads of dog digestive problems will present with diarrhea at night. Anything from simple canine gastroenteritis and colitis to inflammatory bowel disease in dogs can show this symptom. 

The disease doesn’t have to come from the GI tract. Canine pancreatitis can also be an underlying cause of nighttime diarrhea. “The classical signs in the dog are appetite loss, vomiting, diarrhea, a painful abdomen, and fever or any combination thereof. Pancreatitis can come on suddenly and seemingly out of nowhere or it can be a smoldering on-going condition that waxes and wanes.”, says Dr. Wendy Brooks.

Kidney and liver failure will cause a buildup of toxins in the body causing dogs diarrhea. Most diseases are usually combined with other symptoms. Your vet will need to check out the dog and decide how they should treat it further.


If your dog keeps having diarrhea at night, the reason might be some kind of an intestinal parasite. Dogs can get infected with parasites by eating contaminated food, or water, or eating their own feces. Some common parasites that attack dogs include hookworms, tapeworms, roundworms, coccidia, and giardia.

These infections will usually cause additional symptoms like lethargy, malnutrition, or bloody stool. They are more common in puppies, senior dogs, or dogs with weak immune systems. Besides parasites, a lot of bacteria like E.coli and Salmonella can also cause nightly diarrhea in dogs.

What Should I Do If My Dog Has Diarrhea All Night?

To start, change up the dog’s diet to foods like plain rice and chicken. Give some OTC medication like Loperamide and give lots of water to the dog. If the diarrhea is not resolved within 24 hours, take your dog to the veterinarian. But there are also ways to prevent this from happening.

Avoid Stressful Situations

We know that stress can be a big factor causing nighttime diarrhea in dogs. The first step in preventing this diarrhea is to keep your dog stress-free. Firstly, don’t leave your dog alone for long hours during the day to prevent separation anxiety.

Then, try to give it a safe space, where it can relax and relieve itself from frustration. Crate training can help with this. You can also try giving some supplements to the dog to calm it down during the night. Valerian root is great for dogs as it is a natural remedy meant to cause relaxation.

Change The Diet Slowly

If it is time to switch your dogs diet, you shouldn’t rush to do it. This process should take your dog around 1-2 weeks to be successful. Try mixing the new food with the old one, putting more and more of the new each time. Throughout this time, make sure you supervise the dog for any changes in its health. Also, avoid giving new food at night to prevent allergic reactions.

If the dog already has a bad bowel movement, you can introduce a bland diet to help. Foods like plain rice and boiled chicken are great for stopping diarrhea in dogs. Pumpkin will stop dog diarrhea quickly in a day or two.

Probiotics And Supplements

If you want to stop dog diarrhea at night, you can try giving your dog some medications. Probiotics are healthy bacteria that live in the gut and help maintain healthy digestion. Lactobacillus and bifidobacterium are an example of this. You can give your dog probiotic supplements as pills or as foods like yogurt and kefir. Digestive enzyme supplements for dogs are another great option.

Dietary fiber supplements for dogs will also help bulk up the dogs stool and decrease the occurrence of puppy diarrhea. It can also come in different foods. Pept-Bismol is an OTC that is recommended for gastrointestinal health issues. An effective canine diarrhea home remedy is peppermint tea.

Get It Dewormed And Vaccinated

If the dog is suffering from some kind of infection or illness, your vet should help you diagnose and treat it. Dogs that are infected with parasitic worms need to be dewormed. 

To prevent your dog from encountering some diseases that cause nighttime diarrhea, you should also get it vaccinated. There are vaccines for viral infections like parvovirus, coronavirus, and leptospirosis among others.

Another important part of preventing night diarrhea in dogs is to supervise the dog. Pay attention to the dog whenever walking outside so it doesn’t end up eating something from the street.

How Long Is Too Long For A Dog To Have Diarrhea?

Most nightly diarrheas will resolve the next day. If the dog continues to suffer from diarrhea for more than 48 hours, you should ask for help from a veterinarian. That is a sign that something significant is affecting the dog. But in some cases, you should contact your vet earlier.

It is normal to see dog diarrhea in the middle of the night in many cases. If it only happens once in a while and resolves quickly, there is nothing to worry about.

When To Contact A Vet 

Supervise the dog when it has a loose stool. If the puppys diarrhea is accompanied by other symptoms or is not stopping, you will need veterinary attention. 

Examine the feces from the dog. If you find blood, pus, worms, or an unusual color or smell, it might signal something more serious with the dogs poop. Sometimes, if the dog leaves wet spots and it’s not urine, it may be a sign of diarrhea. The dog might experience changes in its appetite, and behavior, or have intense pain in its abdomen. Fever, lethargy, vomiting, and dehydration are also notable symptoms that need emergency care.

The vet will do a thorough examination of the dog and decide on its diagnosis. Then, they will prescribe the needed therapy to stop the nightly diarrhea your dog suffers from.

So What Causes Diarrhea In Dogs At Night? – In Short

Many things can cause your dog to experience a watery stool at night. The dog might be stressed or anxious, or have some serious health issue like a viral infection that needs addressing. You might have recently changed its diet too quickly, or given it something it’s allergic to. Or you might have started giving some human medication that causes diarrhea and upset stomach as a side effect.

If your dog has explosive diarrhea, there are things you can do to help it. Keep the dog in a low-stress environment and provide a safe space for it. Change the diet to plain rice and pumpkin to decrease the watery stools. Give supplements like fiber and probiotics to improve gut health. If you as the dog owner can’t help the dog yourself, contact your vet. They will give it medications like dewormers or antibiotics that will help it deal with nighttime diarrhea.


What should I do if my dog has bloody diarrhea?

Diarrhea by itself is not always problematic, but if you notice blood in it, contact your vet immediately. Try to notice if the blood is light or dark black as it has importance for the diagnosis.

Why does my dog have diarrhea with no other symptoms?

If your dog has only diarrhea at night and nothing else, the reason is most certainly related to food. The dog might have eaten something it shouldn’t have, or is allergic to the food you gave it before sleeping.

What ingredient in dog food causes diarrhea?

The most common reason for dog diarrhea would be gluten present in pasta, biscuits, and bread. Another reason is all the dairy products like milk and cheese. Raw food can also cause acute diarrhea if not kept properly.

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You can find a lot more information on how to keep your dog healthy on our site Dogisa!

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