Understanding Why Dogs Get Diarrhea

by | Dec 5, 2025 | Albany Dog Trainer

Understanding Why Dogs Get Diarrhea

Diarrhea is one of the most common issues dog owners encounter, and it can send even the most experienced pet parents into panic mode—especially when it seems to appear out of nowhere. But in reality, diarrhea is often the body’s way of reacting to something it doesn’t agree with, whether that’s food, stress, bacteria, or an underlying condition. By understanding the causes and knowing when to take action, you can help your dog recover more quickly and comfortably.

Understanding Why Dogs Get Diarrhea

Common Causes of Diarrhea in Dogs

Dogs can experience diarrhea for a variety of reasons—some mild, some more concerning. Here are the most frequent causes:

1. Dietary Indiscretion (A.K.A. “Garbage Gut”)

Dogs are natural explorers, especially when it comes to food. Eating something spoiled, fatty, or non-edible—like trash, table scraps, toys, or yard debris—can send their digestive system into chaos. This is one of the top causes of sudden diarrhea.

2. Sudden Diet Changes

Switching foods too quickly can disrupt the bacteria and enzymes that live in your dog’s gut. Even switching brands or protein sources can cause temporary GI upset. Slow, gradual transitions are essential.

3. Food Sensitivities or Allergies

Some dogs have sensitivities to specific proteins, grains, or ingredients. These sensitivities can trigger chronic diarrhea, itching, gas, and discomfort.

4. Stress or Anxiety

Just like humans, dogs can get an upset stomach when they’re stressed. Travel, boarding, visitors, loud noises, or changes at home can all lead to loose stools.

Understanding Why Dogs Get Diarrhea5. Parasites

Intestinal parasites—such as giardia, hookworms, whipworms, or roundworms—can cause diarrhea that may appear chronic or intermittent. Puppies especially are vulnerable.

6. Bacterial or Viral Infections

Contaminated water, spoiled food, or exposure to infected dogs can introduce harmful bacteria or viruses. Parvovirus, for example, can be extremely serious and requires immediate vet care.

7. Medications

Antibiotics, pain medications, or steroids can disrupt the normal bacterial balance in the gut, leading to diarrhea as a side effect.

8. Underlying Medical Conditions

Chronic diarrhea may be a symptom of deeper issues like pancreatitis, liver disease, inflammatory bowel disease, Addison’s disease, or endocrine disorders.

When Is Dog Diarrhea a Medical Emergency?

While many cases of diarrhea resolve quickly with simple care at home, you should contact your veterinarian if you notice any of the following:

  • Diarrhea lasting more than 24–48 hours

  • Blood in the stool (red or black/tarry)

  • Vomiting combined with diarrhea

  • Lethargy or weakness

  • Fever

  • Loss of appetite

  • Signs of dehydration (sunken eyes, sticky gums, reduced urination)

  • A puppy, senior dog, or immunocompromised pet with persistent symptoms

If your dog seems “off” or the diarrhea is severe, don’t wait—early vet care can prevent complications.

Understanding Why Dogs Get DiarrheaHow to Help Your Dog at Home (The Safe, Vet-Approved Basics)

While this blog is mostly about understanding the causes, it helps to know the first steps you can take at home:

1. Give the GI Tract a Rest

Most vets recommend a short fasting period—usually 12–24 hours—for adult dogs (not puppies!) if diarrhea is sudden. This allows the digestive system to settle.

2. Hydrate, Hydrate, Hydrate

Diarrhea can dehydrate dogs quickly. Offer small sips of water frequently, and consider electrolyte solutions made specifically for pets.

3. Switch to a Bland Diet

Once the stomach has rested, a bland diet helps the gut reset. Typical options include:

  • Boiled chicken and white rice

  • Boiled lean ground turkey and rice

  • Plain canned pumpkin

  • Prescription GI diets

4. Add Gut-Soothing Supplements

With your vet’s approval, options like probiotics, digestive enzymes, or stool-firming powders can help restore balance.

5. Keep an Eye on Things

Monitor stool quality, frequency, hydration, and appetite to ensure things are improving.

Can You Prevent Future Digestive Upset?

While not every episode of diarrhea is preventable, these habits can make a huge difference:

  • Avoid sudden diet changes

  • Keep harmful foods, toxins, and garbage out of reach

  • Maintain regular deworming and fecal exams

  • Manage stress during travel or major changes

  • Use consistent feeding routines

  • Provide safe, appropriate chews (avoid bones, rawhide, or unsafe items)

A healthy gut is one of the foundations of a healthy dog.

Final Thoughts

Diarrhea in dogs may be messy and stressful, but it’s also incredibly common—and in many cases, it’s easily managed with a little care and understanding. Knowing the triggers and warning signs helps you respond appropriately and get your pup back to feeling their best.