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Dog Symptom Guide

Dog Diarrhea

Most cases are mild, but dehydration and blood in stool are warning signs.

Dog Diarrhea guide image

Evidence

Review status / Updated / Sources

Review status: Clinical reviewer not listed

Updated: February 13, 2026, 3:00 AM UTC

Sources:

Owner next steps

What to do now

Loose stool can be mild, but blood, dehydration, weakness, or repeated diarrhea changes the next step.

Monitor

  • Track stool frequency and appearance.
  • Offer normal access to water.
  • Keep notes on food changes, treats, medications, and exposure risks.

Call a vet

  • Call today if diarrhea repeats, lasts beyond a day, or comes with vomiting.
  • Call sooner for puppies, seniors, or pets with known illness.
  • Ask what stool sample or visit timing your clinic recommends.

Emergency now

  • Use emergency care if your dog is weak, collapses, has black stool, or cannot keep water down.
  • Use emergency care for repeated bloody diarrhea or signs of dehydration.
  • Do not wait if diarrhea follows possible toxin exposure.

Red flags

  • Collapse or severe weakness
  • Black stool or repeated blood
  • Repeated vomiting with diarrhea
  • Very young puppy or medically fragile dog

Possible causes

These are non-diagnostic examples to help frame a veterinary conversation.

  • Diet change or dietary indiscretion
  • Parasites or infectious disease
  • Inflammatory or systemic illness

Reference guide

What this symptom can mean

  • Acute diarrhea: Read condition details and warning signs.
  • Addison’s Disease (Hypoadrenocorticism): Read condition details and warning signs.
  • Canine Infectious Hepatitis (Adenovirus): Read condition details and warning signs.

What to track before the vet

  • When signs started and whether they are getting worse
  • Appetite, water intake, and overall energy in the last 24 hours
  • Any vomiting, diarrhea, blood, collapse, or breathing changes
  • Recent food changes, new treats, medications, or toxin exposure

When to get care

Use the intake flow if you want a structured way to organize the symptom details before you contact a professional. Seek prompt care when signs are severe, worsening, repeated, or paired with breathing trouble, collapse, pale gums, pain, or inability to keep water down.

How to use this page

This symptom page is educational only. It helps you collect context and compare related condition pages, but it does not replace a veterinary exam or final care-routing decision.

Need guided next steps?

Symptom pages are educational references. Start symptom intake for guided questions and personalized care-routing guidance.

Start symptom intake Find care near you Find emergency care

Frequently asked questions

Brief mild diarrhea can sometimes be monitored, but worsening signs, blood, vomiting, or dehydration need veterinary guidance.

Track timing, stool appearance, vomiting, appetite, water intake, energy, and recent food or medication changes.

Related conditions

Acute diarrhea Read condition details and warning signs. Addison’s Disease (Hypoadrenocorticism) Read condition details and warning signs. Canine Infectious Hepatitis (Adenovirus) Read condition details and warning signs. Canine Parvovirus (Parvo) Read condition details and warning signs.