Dog Diarrhea

Dog Diarrhea: Causes and When to go to the Emergency Vet

Medical Contributor:

Dr. Alexander Gascoyne

Feb 21, 2023

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Does your dog have diarrhea? Is canine diarrhea ever something to worry about, or is your pet generally going to be okay if she’s suffering from this symptom? What does it mean when your dog has diarrhea, and when is it an emergency?

In the article below, we’ll answer all these questions and more. With the help of this guide, you should have a better understanding of what it means when your dog has diarrhea, what could be causing it, and when you need to treat it like an emergency as well. Read on to find out more.


Listed below are the main causes for this condition:


One of the most common causes of diarrhea in dogs is a change in diet. If your dog’s food has been suddenly changed to a new flavor or brand without weaning her off of the first one, or if you’ve started giving her new types of treats, these could be the causes of her diarrhea. This type of diarrhea usually clears up quickly.


Some dogs may develop diarrhea when they overexert themselves or become overexcited about something. If your dog has been playing too hard or if she’s gotten excessively worked up, you may notice she has a couple of rounds of diarrhea before her digestion goes back to normal. This problem should clear up in about a day.

Bacterial or Viral Infection

Dogs with bacterial or viral digestive infections typically develop diarrhea. Diarrhea can be a symptom of a wide range of infections in dogs, so it’s important to have your pet checked by a veterinary professional if you suspect she could be sick with something.


Parasites, especially those that affect the digestive system, are commonly associated with diarrhea in dogs. If your dog is on a regular de-wormer, this typically won’t be a problem for her. However, worms and other intestinal parasites are especially frequent in young puppies who haven’t been dewormed yet.

Food Intolerance or Allergy

Dogs who have an intolerance or an allergy to certain ingredients in their food may suffer a round of diarrhea after eating. If your dog’s diarrhea seems to be associated with the times when she eats, this could be the cause. Try changing her to a different, higher-quality food to see if it makes a difference.


Stress is a major contributing factor in canine diarrhea. Dogs who are overly stressed or upset about something usually have a few rounds of diarrhea before going back to normal. Your dog’s diarrhea should clear up after the stress factor has been removed, and after you give her a little bit of time to calm down following the issue.

Emergency Situations

Listed below are dog diarrhea situations where you should call your emergency vet:

Bloody Diarrhea

Blood in the diarrhea can sometimes be an emergency. If the blood is bright red and streaked, however, this is probably caused by hemorrhoids and is nothing to worry about. If the blood is dark red or black, this is an emergency and should be treated right away.

Uncontrollable Diarrhea

If your dog’s diarrhea is uncontrollable to the point that she cannot even get outside before it occurs, this is an emergency as well. Go to the emergency vet right away for uncontrollable diarrhea.

Diarrhea Longer than 24 Hours

Diarrhea that lasts longer than 24 hours is very concerning and may be an emergency. If your dog has no other symptoms, you may be able to see your regular vet for long-lasting diarrhea. However, if the regular vet is unavailable or your dog shows other symptoms of an issue, go to the emergency vet instead.

Diarrhea with Dehydration

Dehydration is quick to occur in dogs who have multiple bouts of diarrhea. If your dog’s eyes appear sunken, if her heart rate is high, or if her skin does not “snap” back into place immediately when you lift it at her shoulder blades, these are all signs of dehydration. Dehydration can be deadly if left untreated for too long.

Diarrhea with Vomiting

Vomiting along with diarrhea is common but can quickly lead to dehydration as well. If your dog vomits and has diarrhea more than once or twice, go to the emergency vet, as she may need IV fluids to recover.

Seek Veterinary Care for Dog Diarrhea

Based on this information, it’s easy to see how concerning diarrhea can become. The good news is that diarrhea is not typically a problem for dogs, and in most cases, it will resolve in just a short amount of time. However, if your dog’s diarrhea lasts longer than a day or contains any blood, then this is a more concerning situation. When in doubt, always go to the emergency vet if you suspect your dog may be dealing with a health crisis. Otherwise, it’s usually okay to wait 24 hours and see how your pet’s health is doing before you rush off to the vet.

If you’re concerned about dog diarrhea, or if you have any other questions about your pet’s health, call or bring your cat in to any of our VEG locations. With locations all over the country, we have emergency veterinarians available 24/7 to help guide you in the best direction and make sure your cat receives the care they need.