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Home > Ask A Vet > When Is Dog Diarrhea an Emergency? 5 Situations (Vet Answer)

When Is Dog Diarrhea an Emergency? 5 Situations (Vet Answer)

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Dr. Iulia Mihai

Veterinarian, DVM MSc

The information is current and up-to-date in accordance with the latest veterinarian research.

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Diarrhea in dogs is common and can occur for various reasons, typically being food related. But when is diarrhea in dogs an emergency?

You know your four-legged friend best, so go to the vet immediately when you feel that something is wrong with them. That said, diarrhea typically becomes a cause for concern and an emergency when your dog has multiple watery stools that last more than a day and/or are bloody, they lose their appetite, they are lethargic, and they are in pain and/or vomiting. If your dog presents these signs, take them to the vet as soon as possible because they risk dehydrating, and dehydration can be fatal if not treated in time.


When Does Diarrhea in Dogs Become a Medical Emergency?

It’s normal for dogs to occasionally have a diarrheal stool that resolves on its own. When it persists or other clinical signs occur, diarrhea becomes a medical emergency and requires a visit to the vet.

1. Diarrhea With Blood

Bloody diarrhea can occur in dogs for many reasons, most of which represent medical emergencies. The most common ones are:

  • Foreign bodies
  • Ingestion of toxins
  • Infectious diseases (e.g., parvovirus)
  • Intestinal parasites
  • Anal gland problems

The blood in the diarrheal stool can be bright red (fresh blood) or dark red (old or digested blood). When the blood is bright red and streaked, it means that a bleeding has occurred somewhere in the terminal part of your dog’s intestine. Diarrhea with bright red blood can occur due to parvovirus, foreign objects, hemorrhoids, anal gland problems, etc.

When the blood is dark red, it means it is old or digested, a situation in which a bleeding has occurred in the proximal part of the digestive tract. Diarrhea with dark blood can occur when your dog’s intestine is obstructed or if they suffer from a gastric ulcer (which happens to coincide with diarrhea).

In any case, take your dog to the vet as soon as possible.

a shih tzu dog being checked by two vets
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2. Diarrhea That Lasts More Than 24 Hours

Transient diarrheal stools usually go away on their own within a day. If the diarrhea lasts more than a day, your dog will start to dehydrate (because they lost water) and develop malnutrition. Even if your dog does not show any other clinical signs, it is recommended to contact the veterinarian for this reason.

Dehydration is a medical emergency because if it is not treated in time, your dog can die. Clinical signs of dehydration in dogs include:

  • Lethargy (your dog lacks energy and is apathetic)
  • Sleeping more than usual
  • Lack of appetite
  • Sunken eyes
  • Warm and dry nose and lips
  • Tacky mucous membranes
  • Panting
  • Increased heart rate

3. Uncontrollable Diarrhea

Uncontrollable diarrhea is when your dog can no longer wait until they get outside to do their business and eliminates wherever they can. It can be a sign that they ate something that they shouldn’t, but it can also be a sign of an infectious digestive disease. Contact the veterinarian as soon as possible.

4. Several Diarrheal Stools in a Day

If your dog has more than two episodes of diarrhea in a day, it is time to contact the veterinarian. When the amount that they eliminate is small and watery, it may be a foreign object that they swallowed and blocked their intestine. This case represents a medical emergency, and you must contact the veterinarian as soon as possible.

Dog Pooping
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5. Diarrhea and Vomiting

Diarrhea with vomiting leads quickly to dehydration. Usually, these two clinical signs do not go away on their own, and you must take your dog to the vet even if they had diarrhea and vomited only twice.

Since dehydration will set in quickly in this case, it is important to go to the veterinarian for the proper treatment, which is rehydration with intravenous fluids.


What Are the Causes of Diarrhea in Dogs?

When your dog has three or more watery stools in a day, it can be said that they have diarrhea. It’s not a disease in itself, but rather a clinical sign of other conditions that often require treatment. Here are the most common causes of diarrhea in dogs:

  • Food allergies or poisoning (caused by an improper diet or old or unsuitable foods)
  • Vaccination (diarrhea may occur as an adverse effect, typically resolves in a day)
  • Certain drugs, e.g., antibiotics (dogs can be sensitive to certain antibiotics and develop diarrhea; these drugs also kill the good intestinal bacteria, causing a microbial imbalance)
  • Viral or bacterial infectious diseases (e.g., parvovirus, distemper, campylobacteriosis, salmonellosis, helicobacteriosis, etc.)
  • Overexertion (when subjected to intense physical exertion, some dogs may have one to two diarrhea episodes in a day, which will resolve on their own)
  • Stress (stressed or anxious dogs may have a few episodes of diarrhea, but these usually resolve on their own)
  • Toxic substances or toxic plants (ingestion of these substances can lead to diarrhea and other clinical signs)
  • Deworming
  • Intestinal worms
  • Pancreatic diseases
  • Liver diseases
Owner cleaning up after the dog poop with plastic bag
Image Credit: Monika Wisniewska, Shutterstock

Frequently Asked Questions (FAQs)

What If My Dog Has Diarrhea for 3 Days?

If your dog has diarrhea for 3 days, it is necessary to contact the veterinarian. You should always contact the vet if your dog has had diarrhea for more than 24 hours. Persistent diarrhea can lead to dehydration, which is a medical emergency. Also, the veterinarian will determine the cause that led to the diarrheal episodes and institute the proper treatment.

Should I Let My Dog’s Diarrhea Run Its Course?

In transient cases, diarrhea will pass by itself within a day. If the diarrhea persists for more than 24 hours, take your dog to the vet as soon as possible. Persistent diarrhea can lead to malnutrition and dehydration. If diarrhea is accompanied by vomiting, dehydration will definitely set in much faster. Dehydration is a medical emergency because your dog can die if it is not treated in time. Therefore, don’t let the diarrhea run its course if it lasts more than 24 hours.

Sad hispanic woman looking upset while caring for her aged ill border collie dog at the veterinary clinic
Image Credit: antoniodiaz, Shutterstock

divider-dog Conclusion

One or two watery stools in a day or every now and then is likely not a medical emergency. But if your dog has multiple watery stools in a day or the diarrhea lasts more than 24 hours, is bloody, or is accompanied by vomiting or other clinical signs, it represents a medical emergency, and you must contact the veterinarian as soon as possible. It is recommended not to wait for the diarrhea to go away on its own if it lasts more than a day because you risk your dog becoming dehydrated, and severe dehydration can lead to death. Diarrhea can have several causes, the most common being dietary indiscretions, infectious diseases, ingestion of toxic substances or foreign bodies, and intestinal parasites.

Featured Image Credit: SasaStock, Shutterstock

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