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Why Does My Puppy Have Loose Stools at Night? 7 Reasons

Waking up to the sight and smell of dog’s diarrhea can be equal parts alarming, annoying, and just plain gross for pet parents. When it’s just a young pup that’s responsible for that mess, though, it’s easy to get concerned. 

Should you get concerned, though? Or is this just a normal rite of passage? Why does my puppy have loose stools at night? Your pup might not be getting enough sleep because of these nocturnal diarrhea sessions, and they do need their sleep. And there are plenty of reasons why your furbaby might be passing loose stools at night. 

Some will put your mind at rest, while others can be worthy of a vet trip, so it’s a good idea to know the different signs that’ll indicate which it is.

This post will discuss all the possible reasons for abnormal nighttime puppy diarrhea, what you can do about them, and when it’s time to take them to your vet. 

puppy-sleeping-on-other-dogs-head why does my puppy have loose stools at night

Why Does My Puppy Have Loose Stools at Night? 7 Reasons

Trying to play a guessing game of “what’s causing my puppy’s diarrhea” might just drive you mad; at the very least, it’ll probably spark a phone call to the vet for advice. Either way, here are some of the most common reasons for problems with your puppy’s digestive system. 

1. Dietary Changes

In general, dogs can be sensitive to a new diet, but a puppy is more likely to encounter these changes a few times in a short period of time. When they transition from milk to puppy food is the first big step, and when you bring them home from the breeder or rescue is another. The next is when they move from puppy food to adult food. 

At any one of these transition stages, your fluffy friend’s intestines and stomach need to adapt to the new sources of protein and nutrients. This may take some time, so it’s best to introduce the food slowly alongside their old food to avoid smelly complications. 

puppy with tongue out and curled

Usually a quarter of new food to three-quarters of the old food to start with is good, and then when they tolerate that happily, up the measurement to half and half. Continue this gradual increase of the new food until your good boy or girl is exclusively eating the new food with no complications. 

2. Food Intolerance or Allergy

Just like us, our doggos can have food allergies or intolerances. Dairy, beef, egg, chicken, and corn are all common reaction-inducing allergens for your puppy. Allergies can occur when there is an abnormal immune response against the offending culprit, and one manifestation of this can be diarrhea or vomiting. 

This is quite different from food intolerances. There is no immune response, but their puppy bodies simply can’t digest the food in question properly, leading to a case of the trots. If you suspect this is the case, your vet will help you figure out the cause in one of a few ways. The most expensive is an allergy blood test; otherwise, a skin test is also quite efficient. 

They do cost a pretty penny, so sometimes the most time-consuming route is recommended — a food elimination diet, a bland diet and eventually a specific dog food for allergies. 


3. Stress

It happens to humans too, believe it or not. When stress hits, your canine companion’s gut can be affected, and the result can be a sudden or recurrent episode of diarrhea. There may be a stressor affecting your puppy negatively at night

If they’ve just arrived at your place, they might feel lonely while adapting to their new environment without the comfort of their littermates. They may also feel neglected if they’re used to a higher degree of socialization at night time or if there is a sudden change in their routine. 

The emotional distress this can cause is enough to upset their tummies and trigger night-time stress-related diarrhea. Buying them one of these snuggle puppy toys with a simulated heartbeat and warmth pack can help them feel safer and less alone at night, and hopefully curb explosive episodes. 

Shih Tzu Mixed with Yorkie brown puppy

4. Parasites

Puppies need frequent deworming in the first several months of their lives. At this age, their immune system is still developing so it’s still fairly weak. Therefore, they’re more likely to be vulnerable to picking up intestinal parasites from contaminated water or soil and resulting bacterial infections.

It’s pretty icky to think about your poor puppy playing host to squirmy things like roundworms, hookworms, giardia, or coccidia. Any one of these nasty things can cause stomach upsets and resultant runny tummies, which is why it’s important to maintain a good deworming schedule with a decent product. 

Pomeranian Mixed Shih Tzu brown and white pu

Even if you are vigilant, though, sometimes those parasites can sneak in anyway. Watch your puppy’s stools for any signs of infestation and ask your vet for advice. 

5. Medication

If your furry friend is on some medications, check the leaflet in the box because diarrhea might just be a side effect. There’s no need to panic, though. Even the deworming meds that you give your furbaby to help alleviate their tummy troubles may inadvertently cause some diarrhea. 

If the cause is medication, the symptoms are usually rectified once the medicine responsible is either finished or switched at your vet’s discretion. 

6. Dietary Indiscretion

This differs from dietary changes in a big way. Dietary Indiscretion refers to a change of eating habits where your dog becomes less fussy about what they’ll eat and begins to eat things that are potentially bad for them. 

puppy licks human arm

Let’s be honest. This is more likely to happen at the puppy stage when they’re still learning what’s fit for eating and what they should avoid. Raw or spoiled food, carcasses, feces, garbage, and toxic plants are just a few of the things that may suddenly seem delicious to your dog. 

When consumed, these disgusting delicacies allow toxic substances and bacteria to gain entry to the blood, causing what vets call “garbage toxicosis” or “garbage gut.” Other symptoms besides diarrhea that accompany this unfortunate predilection include vomiting, lethargy, and loss of appetite. 

Needless to say, a trip to the vet is what needs to happen to sort your pupper out, as well as a vigilant eye to make sure their eating lifestyle is improved.  

golden labradoodle puppy on grass

7. Illness

Puppies can still be vulnerable to many diseases while their immune systems are developing. They may develop colitis or even a bit of Inflammatory Bowel disease or Syndrome (IBS), which is not an emergency and can be treated fairly easily. 

Other illnesses are not so benign, though. One of the most dangerous is Canine Parvovirus. It’s highly contagious, typically attacks puppies between 6 – 20 weeks of age, and progresses fast. It also has a high mortality rate in young pups, so this disease isn’t to be taken lightly. 

The first signs of it are lethargy and lack of appetite, then it moves quickly to severe vomiting and bloody diarrhea.

The vaccines that puppies have in their youth are specifically to prevent this horrific illness. So, until your pup is fully vaccinated, it’s best to keep them away from areas of high public dog traffic to avoid any potential exposure. If you do notice any of these symptoms, take your little one to the vet immediately.  

puppy in bed

Frequently Asked Questions

What Do I Do if My Puppy Has Diarrhea?

There are a few different ways you can go about treating diarrhea in pups. One way is to withhold food for 12 – 24 hours if they’re healthy and old enough to handle this. It allows the digestive tract to rest and reset, as well as clear out whatever was causing the problem. Then you can then start giving them small amounts of highly digestible food that’s also binding. 
The best way of binding watery stools is to feed them fiber-rich freshly boiled plain pumpkin or some plain pumpkin purée. Plain cottage cheese is also great for their upset tummies as it is a natural probiotic, and plain cooked egg is an easily digestible high protein food. Or try some white rice. 
There are also medicinal routes you can go, usually a paste that your vet can recommend to firm up stools or a gut-specific antibiotic depending on the cause. You could also give your fluffy friend a decent probiotic to help reintroduce good bacteria in their gut and reestablish a balance of their intestinal flora. Whatever your plan of action, always discuss it with your vet first.  

When Should I Worry About My Puppy’s Diarrhea?

Not every case of tummy trots is worthy of a vet visit, especially for a puppy. Even healthy pups will pass the occasional loose stool as their immune systems are still getting stronger, so they’re more sensitive to changes and infection than older dogs. It’s time to start worrying a little if it turns into chronic diarrhea or if it’s getting worse, as the risk of dehydration increases then. So if you notice your pupper is having more frequent stools at night and they won’t firm up, or weight loss it’s time for a vet visit.
If you notice other symptoms accompanying diarrhea, such as lethargy, lack of appetite, or otherwise unusual behavior, this can be a cause for concern. Especially if dog diarrhea begins to smell very foul or streaks of red or black (digested) blood begin to appear. If you notice any of these signs, it’s best to jump in the car and get to the vet immediately. 

Final Wrap-Up On Why My Puppy Has Loose Stools at Night

From stress to colitis to viral infections and parasites to a change in your dog’s diet, there are a bunch of different reasons as to the underlying cause of why your pup may be getting nighttime diarrhea. 

It’s never pleasant, but an upset stomach doesn’t necessarily have to be something to worry about. As long as you keep an eye on your pup and contact the vet if things aren’t getting better, you’re the best dog parent to them that you can be. 

If your puppy is new, socialization is superbly important in the first few months of their lives. Read more about how you can socialize your puppy here. 

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