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Raising puppies is nerve-wracking. There are so many things to keep track of, from keeping up with vaccine schedules to removing socks and other foreign objects from your puppy’s mouth. As if that wasn’t enough to worry about, many puppies also experience something far less pleasant than chewing the occasional sock, and that’s puppy diarrhea.

What Causes Diarrhea in Puppies?

Diarrhea is one of those frustrating symptoms for owners because it can mean that your puppy has anything from a potentially lethal virus to simple indigestion. Any pet owner who has googled “puppy diarrhea” is well aware that many serious and minor puppy ailments list diarrhea as a symptom, making it hard for owners to determine what is serious and what is not.

Don’t panic. Despite the endless lists of horrifying diseases out there, there are six main causes of diarrhea in puppies that you need to know about:

  1. Diet change or food intolerance
  2. Bacterial infection
  3. Viral infection
  4. Ingestion of garbage, toxins, or foreign bodies
  5. Parasites
  6. Stress


There are many reasons why you might switch up your dog’s diet. Maybe your vet recommended a higher-quality brand of food, or your local store ran out of your puppy’s usual kibble. Regardless of the reason, even a simple change in diet can cause diarrhea in puppies.


Your current food could also be the problem. Sometimes puppies develop an intolerance or sensitivity to certain foods or ingredients. If you suspect that your puppy has a food intolerance or sensitivity, talk to your vet about the best way to manage her diet and resolve her diarrhea.

Learn more about the best food for your puppy

Bacterial Infection

Puppies have more delicate immune systems than adult dogs, which makes them more susceptible to bacterial infections. Salmonella, E. coli, Clostridium, and other bacteria can cause puppy diarrhea. These diseases are serious and are usually accompanied by other symptoms, like bloody diarrhea, loss of appetite, fever, and vomiting.

Viral Infection

Perhaps the most worrying cause of puppy diarrhea is a viral infection. The parvovirus and distemper virus are both potentially fatal diseases that affect unvaccinated or partially vaccinated puppies. The coronavirus is also a cause of viral diarrhea in puppies. All viruses require medical attention from your veterinarian.


Puppies eat things that they are not supposed to. From garbage to poisonous plants, if your puppy can reach it, chances are he’ll try and eat it. Consuming garbage, especially garbage full of food, often leads to puppy diarrhea, and in some cases can cause blockages that require veterinary intervention to resolve.

Poisons and toxins also cause diarrhea. Call your vet or local veterinary emergency center immediately if you suspect your puppy ate something potentially harmful.

Learn more foods your puppy should and should not eat


Young puppies are prone to parasites. Whether they are born with parasites or pick them up from the environment, parasites like roundworms, hookworms, whipworms, coccidia, and giardia all cause diarrhea in puppies and all require veterinary attention.


Sometimes the reason behind puppy diarrhea is simple. Stress can cause diarrhea in dogs just like it does in humans, and puppyhood is certainly a stressful time. Your puppy is constantly meeting new people and exploring new things, and adjusting to the routine of your household is sometimes enough to trigger stress-related diarrhea by itself.

When to Call the Vet

With so many causes of puppy diarrhea out there, how do you know when to call the vet and when to wait it out? As a general rule, play it safe. Call your vet and explain your puppy’s symptoms, and let your vet decide if he or she thinks that your puppy needs to come in for a visit.

Most cases of puppy diarrhea are not severe. However, if your puppy has any of the following symptoms, call your vet immediately:

  • Bloody diarrhea
  • Black, tarry stools
  • Fever
  • Pale gums
  • Discomfort or pain
  • Vomiting
  • If you think your dog swallowed a foreign body or toxic substance
  • The diarrhea has been going on for more than one day

puppy diarrhea vet

You should also call your vet if your puppy has not received all of her vaccinations and is having diarrhea. The parvovirus causes diarrhea in puppies and is a potentially lethal infection that requires immediate veterinary attention.

Treating Diarrhea in Puppies

The treatment for your puppy’s diarrhea depends on the cause. Mild diarrhea caused by stress or a dietary transition often clears up with the addition of a bland diet, although it is always a good idea to consult your veterinarian about at-home treatment options and to rule out anything more serious, especially if the diarrhea continues for more than a few hours. Make sure you provide your puppy with plenty of fresh water, as even mild diarrhea is dehydrating.

If your vet diagnoses your puppy with a bacterial or viral infection, you might have to hospitalize your puppy while he recovers. Your vet might prescribe antibiotics to treat primary and secondary bacterial infections, and may also give your puppy intravenous fluids to keep him hydrated during his recovery.

Garbage ingestion might resolve on its own, unless your dog ate something that caused an obstruction, but your vet may recommend switching to a bland diet until your puppy’s diarrhea clears up. Toxins and poisons require immediate veterinary attention, and the treatment varies greatly depending on the toxin.

If your puppy has a parasite, the treatment regimen will depend on the kind of parasite and the severity of the parasite infection. Some parasites clear up with the administration of a medication, while others require a more in-depth approach.

Preventing Diarrhea in Puppies

Most cases of diarrhea in puppies are preventable. Here are some tips to help keep your puppy’s digestive system working smoothly:

  • Transition your puppy to a new diet slowly
  • If your puppy is in a kennel with other dogs, keep the facility clean and use the right disinfectants
  • Vaccinate your puppy at the appropriate ages and keep unvaccinated puppies away from unvaccinated dogs and public places like dog parks and kennels
  • Kennel your puppy when he is not supervised to prevent accidental ingestion of garbage and toxins
  • Talk to your vet about parasite prevention, and pick up after your dog

Diarrhea is your puppy’s way of letting you know that something is wrong. Whether it is an upset stomach or a viral infection, observing your puppy’s bowel movements is one of the best ways owners can monitor their puppies’ health on a daily basis.

Note: This article is not intended as a replacement for veterinary care. If your puppy is experiencing diarrhea, call your vet.
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