Dog Diarrhea: How Serious Is It and What Should You Do?
Urgency level: Depends on the situation
⚠️ See a vet immediately if you notice
- • Diarrhea lasting more than 24 hours without improvement
- • Blood in the stool, or black tarry stools
- • Vomiting at the same time
- • Diarrhea in a puppy or senior dog
- • Noticeably low energy or refusing to eat
✅ These can be monitored at home
- • One or two episodes of soft stool with normal energy and appetite
- • Brief adjustment period after switching to a new food
- • Slightly soft stool with no blood or mucus
Common Causes
There are many possible reasons a dog develops diarrhea:
- Diet: Eating something that doesn't agree with them, switching foods too quickly, or overeating
- Stress: A change in environment, boarding, or moving house
- Parasites: Giardia, roundworms, hookworms, and whipworms are common culprits
- Infection: Viruses such as parvovirus, bacteria like Salmonella or Campylobacter, or intestinal parasites
- Food allergies or intolerances
- Medication side effects — particularly antibiotics, which can disrupt gut flora
- Underlying illness: Pancreatitis, inflammatory bowel disease, tumors, and others
When You Can Monitor at Home
- Just one or two soft stools, with things back to normal shortly after
- Energy and appetite seem completely normal
- Happened right after switching to a new food — still in the adjustment window
- Stools are slightly soft but there's no blood or mucus
Home care tips:
- Withhold food for 12–24 hours (adult dogs only — don't fast puppies for extended periods)
- Make sure fresh water is always available to prevent dehydration
- When reintroducing food, start with something bland: boiled chicken breast and plain white rice
- Feed small amounts more frequently and monitor for 2–3 days
Checking for dehydration: Gently pinch a fold of skin at the back of your dog's neck or between the shoulder blades. If it springs back quickly, your dog is well hydrated. If it returns slowly or stays "tented," your dog may be dehydrated — see a vet.
When to See a Vet Right Away
- Diarrhea continues for more than 24 hours
- Stools contain fresh blood or appear black and tarry
- Vomiting alongside the diarrhea
- Your dog seems very lethargic, weak, or unwell
- Your dog is a puppy or senior (higher risk of rapid dehydration)
- You suspect they may have eaten something toxic
- Suspected parvovirus in an unvaccinated dog (symptoms: bloody diarrhea, severe vomiting, high fever)
Frequently Asked Questions
Related Articles
Dog Eye Discharge and Redness: When to See a Vet
The color and texture of your dog's eye discharge are key indicators of its severity. This article provides a comprehensive guide to distinguishing between normal, minor discharge and yellow-green, purulent discharge that requires urgent veterinary attention.
Read more →
Sudden Increase in Dog's Water Intake: What Could Be the Cause?
A noticeable increase in your dog's water intake (polydipsia and polyuria) can be an early sign of several serious conditions, including diabetes, kidney disease, and Cushing's disease. This article explains how to identify the issue and when to seek veterinary care.
Read more →
Dog Vomiting: When Is It Time to See the Vet?
A complete guide to the common causes of dog vomiting, how to assess urgency, when you can watch and wait, and when to head straight to the vet — including the warning signs of life-threatening bloat.
Read more →