Puppy Diarrhea At Night? 4 Nighttime Diarrhea Causes In Puppies!

For puppies, diarrhea is a widespread and common problem.

An internet search yields a seemingly endless supply of puppy infections, diseases, and conditions whose only warning sign may be nighttime diarrhea.

If diarrhea has recently overcome your young pup, the first thing you need to do is breathe easy.

Luckily for you, if your puppy is experiencing nighttime diarrhea, its cause is usually relatively benign.

4 Nighttime Diarrhea Causes In Puppies

Typically, nighttime diarrhea in puppies is linked to one of a few major causes, all of which are relatively harmless (so long as they are treated!):

  1. Parasites
  2. Stress
  3. Infection (bacterial or viral)
  4. Ingestion of indigestible or otherwise toxic matter: garbage, etc.

1. Parasites

Test for giardia in pets

Parasites are one of the most common nighttime diarrhea causes in puppies.

This is to be expected: your puppy is just starting to come into a relationship with the world.

Unlike human beings, who interact with their environment primarily through touch and sight, puppies primarily interact with their environment through taste and smell.

There are a great many parasites (like from a dead squirrel) your puppy can come into contact with simply through exploring your backyard.

Parasites can be found in dogs of any age, but puppies are more prone to get them as they explore this brand new world.

Typical parasites in puppies include roundworms, giardia, hookworms, whipworms, and more. It’s always a good idea to deworm your pup regularly to prevent parasites.


Giardia (specifically, Giardia intestinalis, Giardia lamblia, and Giardia duodenalis) is one of the most common puppy parasites that can lead to diarrhea, and puppies under six months are the most vulnerable to infection.

Usually, puppies encounter Giardia in the late Fall and early Winter, just as the temperature is beginning to drop. Giardia will hang out in cold, dark puddles and other small, stagnant bodies of water.

The scary thing about Giardia is that humans can get it, too. Taking care of your puppy with diarrhea is bad enough; you don’t want to be taking care of yourself.

Luckily, with Giardia, treatment is easy so long as you get your dog to a vet. Keep the house sanitized so that your puppy doesn’t pass the parasite on to you.


Common Types Of Worms That Can Affect Your Puppy

Another of the most common puppy infections is roundworms– otherwise known scientifically as Toxocara canis and Toxascaris leonina.

Roundworms are an affliction most every dog will encounter during its lifetime, and the vast majority of these will experience roundworms during puppyhood.

Roundworms when not treated can be serious, leading to malnourishment in the adolescent dog.

Typically, roundworms are passed on from the puppy’s mother. Luckily, they are highly treatable.


Hookworms, which are actually the common name of three different parasites, are very common in puppies.

They get their name from the hook-like mouths with which these worms attach themselves to the intestinal wall of your puppy.

Though hardly visible to the naked eye, these worms when untreated can take massive amounts of blood from your puppy’s body, leading to anemia (iron deficiency).

Hookworms typically enter a dog’s system through larvae ingested in the world or through the dog’s mother.

2. Stress

Sad puppy in cage

Another widespread cause of nighttime diarrhea in puppies is stress.

You may find it hard to imagine that your playful, bouncy, loving little puppy could be stressed out, but this is extremely common for young dogs!

The world is a vast place, and it takes a long time (a lifetime!) to adjust to it — this is the case with humans and puppies alike.

If you’ve recently moved homes, changed your puppy’s diet, or incorporated other significant lifestyle changes into your puppy’s life, this could be enough stress to cause nighttime diarrhea.

Puppies, like children, crave stability above all. It would be best if you had a stable environment for your young puppy.

3. Infection (Bacterial Or Viral)

Sick injured Labrador puppy
Cute labrador puppy dog with injured leg sleeping – closeup, shallow depth

Adult dogs and their puppy counterparts are exposed to many bacteria and viruses each day.

Almost all of these bacteria and viruses are conquered by the adult dog’s highly efficient immune system.

On the other hand, puppies don’t find these bacteria and viruses so easy to fight off. Infection can be one of the nighttime diarrhea causes in puppies.

Bacterial Infection

The environment is full of harmful bacteria that may hurt your puppy. A common way for a canine to become exposed is through contact with birds or rotten meat.

E. Coli, Salmonella, Bordetella, and many more can threaten the well-being of your young dog. All of these bacterial infections are serious and must be dealt with by a vet.

If your dog has a fever, vomiting, loss of appetite, or bloody stools, you should immediately call your vet.

Viral Infection

Viral infections are a potentially fatal threat to your puppy.

Canine Distemper is one example of these nighttime diarrhea causes in puppies, and its prognosis is unfortunately bleak.

One of the most common ways canine distemper spreads is through contact with wild animals. Raccoons, in particular, can carry the virus for months.

According to the American Veterinary Medical Association, dogs infected with canine distemper “typically develop runny eyes, fever, snotty nose, coughing, vomiting, diarrhea, seizures, and paralysis.

If your puppy is experiencing these symptoms, the situation is serious. Call your vet immediately.

Luckily, other viruses may be milder.

4. Ingestion Of Toxic Matter

If you suspect your puppy ate something harmful to its health, you’ll want to call your vet immediately.

Potential toxic items include poisonous plants, garbage, human medications, infected animal feces, and more. The best help in this matter will be your vet.

Home Care Or A Vet Bill?

Sleepy dog in blanket lying down with human

Typically, diarrhea is not serious, and home care is the most common solution.

If your puppy is still behaving normally and diarrhea has only been happening for a day, your vet will likely recommend home care.

Here are a few signs you might have a more severe problem on your hands:

Stool. Your puppy’s stool should be a nice chocolate brown. If it is green, this could indicate excessive grass consumption or a more serious problem.

If the stool is black and tar-like, brown with red streaks, brown with white flake-like material, or gray and greasy, a serious problem is likely happening in your puppy’s body and you should call a vet immediately.

Other symptoms. If the diarrhea is accompanied by fever, white gums, discomfort, pain, or vomiting, the cause is likely serious.

If you know your puppy swallowed something toxic. If you know your puppy wasn’t supposed to eat what it ate (like Roundup weedkiller), call the vet immediately.


Dog on grass next to water bowl

So long as your problem is not an emergency, home care can effectively treat nighttime diarrhea causes in puppies.

The most important thing to remember when treating your puppy’s diarrhea is that diarrhea is extremely dehydrating. Provide your puppy with a lot of water as it goes through treatment.

A common treatment of nighttime diarrhea in puppies is not feeding your puppy for a little while until its system can clean itself out.

If your puppy has diarrhea, you should wait at least 12 hours to feed it again. However, in most cases you do not need to wait for more than 24.

When you begin feeding your puppy again, stick to a bland diet at first. Many vets recommend chicken and white rice at first as your puppy begins to eat again.

Then, slowly transition to a different kibble, as your puppy’s old kibble may have been the cause of this new irritation. With a little bit of patience, most nighttime diarrhea causes in puppies are totally treatable without a big vet bill.


Golden retriever puppy eating from bowl

We’ve learned how to treat puppy diarrhea, but an important step in your future will be understanding how to prevent puppy diarrhea. A few really basic remedies can help out your puppy immensely in having a happy stomach.

Transition New Diets Slowly

Puppies have sensitive stomachs, and changing abruptly to a new kibble can throw their entire world out of sync.

Whenever you introduce a new diet to your puppy, you have to make sure you’re doing it at a slow, steady pace.

If your puppy takes a cup of kibble each meal, try putting ¾ of a cup of the old kibble and ¼ cup of the new kibble for a day or two. Then you can transition to half and half, and so on.


One small vaccination now can save your puppy’s life- it’s that important!

As we saw above, one of the scariest nighttime diarrhea causes in puppies is a viral infection.

The good news about the most fatal canine viruses is that they are totally preventable.

Ensure you are keeping your puppy up-to-date on its vaccinations, especially when you take it on playdates or out into the wilderness on hikes and other explorations.

Note that it is possible for vaccinations to cause diarrhea in puppies as a side effect, but this is usually minor and resolves itself in a day or two.

Long-Term Confinement

Close up of husky puppy in cage

Dr. Ian Dunbar, dog trainer and vet in charge of Dog Star Daily, distinguishes between short-term and long-term confinement.

In short-term confinement, the puppy is unsupervised with no recourse to use the bathroom.

In long-term confinement, the puppy may be unsupervised for a larger amount of time as a bathroom (or puppy training pads!) is included in its confinement area.

Be careful about your selection of long-term confinement areas. If you wish to keep your puppy outside- say in your backyard- you either need to monitor it or be absolutely sure there are no toxins for the puppy to ingest.

This is typically very difficult, as bacteria and viruses can live in the soil, garbage can float into your yard from the sky, and some backyards are home to plants that are toxic to dogs.

For this reason, some owners have used kenneling as a solution. A kennel is excellent for short-term confinement, but for long-term confinement it is inhumane. As Ian Dunbar writes, overuse or misuse of the kennel is no different than abuse.

Instead, be sure you can observe your puppy when it is outside, or keep it in the house and give it free range there when you cannot be around to monitor it.

Sanitation, Sanitation, Sanitation

If you are keeping your puppy kenneled with other dogs, you must keep the kennel highly sanitized.

An unclean kennel is a breeding ground for fatal puppy diseases, viral infections, and bacterial colonies.

If your puppy is sharing a kennel, give a sanitary rub down to the place every day. This will help prevent viral and bacterial spread if it occurs.

Nighttime Diarrhea Causes In Puppies: Frequently Asked Questions

Golden retriever puppy sitting in its bowl

Have more questions about nighttime diarrhea in puppies? We have the answers.

Why Is My Dog Having Diarrhea Every Night?

Nighttime diarrhea causes in puppies are variegated and specific.

Most likely, one of the following is the cause of your dog’s diarrhea: stress, change in diet, ingestion of foreign matter, infection, or parasites.

If other symptoms, such as vomiting, bloody stool, or white gums accompany your dog’s diarrhea, see a vet immediately.

Is It Normal For Puppies To Have Occasional Diarrhea?


Many puppies have diarrhea, and the causes of these can range from extremely mild to potentially fatal.

In most diarrhea instances, the puppy remains acting normal, and symptoms dissipate after a number of hours. If symptoms persist, call your vet.

Are Puppies More Susceptible To Giardia?

Yes. Puppies are more susceptible to giardia and every other bacterial infection.

The reason for this is two fold.

One, because their immune systems are still undeveloped, and two, because they eat foreign items (like pacifiers) in their environment far more than even adult dogs.

Can Puppies Have Diarrhea From Teething?

Some sources will suggest that diarrhea may result from teething.

More likely, your puppy has chosen a suboptimal item for teething. This toxic matter is the most likely cause for puppy diarrhea.

Take a look at our article on the Best Wood-Like Chew Toys For Dogs for safe yet satisfying toys that you can give to your pup!

What Can I Give My Dog To Harden His Stool?

The most common method is chicken and rice.

As we mention in the Treatment section above, be sure to take your dog off food if it is experiencing nighttime diarrhea for at least 12 hours.

Then, reintroduce food with a bland chicken and rice diet before transitioning back to kibble.

Can Bones Cause Diarrhea In Puppies?

If your dog has been chewing on a bone and swallowed a significant amount of it, it can cause diarrhea.

Bones are not digestible to dogs, and as such, your puppy may have diarrhea as it tries to pass this foreign object safely through its system.

A good rule of thumb with all non digestible chew toys is to always observe your puppy. Do not let it consume what will be harmful to it, and no problems should occur!


Your puppy needs care and support during times of pain and suffering. Health problems in your puppy, such as diarrhea or dysentery, can make them very weak. Hence adopting the proper medical care or visiting your vet, apart from providing remedial care at home, is necessary.

With the above-mentioned caring method, you will surely be able to provide them some relief before it becomes too excruciating for them. However, vet care is the only solution; if you are doubtful and do not have much confidence or thinking, things can become extreme.

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