What causes diarrhea in canines (dogs)?

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Last updated: May 26, 2025View editorial policy

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From the Guidelines

If your dog has diarrhea, you should withhold food for 12-24 hours while providing plenty of fresh water to prevent dehydration, then gradually reintroduce a bland diet of boiled white rice and plain boiled chicken (ratio 2:1) in small portions. For mild cases, you can give over-the-counter medications like Pepto-Bismol (1 teaspoon per 10 pounds of body weight every 6-8 hours) or Imodium (0.1 mg per pound of body weight every 8-12 hours), but avoid these in puppies or dogs with certain medical conditions 1. Contact your veterinarian immediately if diarrhea persists beyond 48 hours, contains blood, is accompanied by vomiting, lethargy, or fever, or if your dog appears dehydrated. Probiotics like FortiFlora (1 packet daily) can help restore gut flora. Diarrhea occurs when food moves too quickly through the digestive tract, preventing proper water absorption, and can be caused by dietary indiscretion, sudden food changes, stress, parasites, or more serious underlying conditions. Some of the possible causes of diarrhea in dogs include:

  • Dietary indiscretion
  • Sudden food changes
  • Stress
  • Parasites
  • Infections with bacteria such as Salmonella, Shigella, Campylobacter, Yersinia, or Clostridium difficile 1
  • Infections with viruses such as norovirus or rotavirus 1
  • Infections with parasites such as Giardia or Cryptosporidium 1 Always transition to new foods gradually over 5-7 days to prevent digestive upset, and keep trash and toxic foods out of your dog's reach. It's also important to practice good hygiene, such as washing your hands frequently, especially after handling your dog's stool or coming into contact with contaminated areas, to prevent the spread of infection 1. If you suspect that your dog has a more serious underlying condition, such as inflammatory bowel disease or gastrointestinal cancer, you should seek veterinary attention immediately 1.

From the Research

Dog and Diarrhea

There are no research papers to assist in answering this question as the provided studies are related to human diarrhea and its treatment.

Related Studies on Diarrhea

  • The management of diarrhea can be divided into three categories: supportive therapy, symptomatic therapy, and specific therapy 2
  • Acute diarrhea often runs a self-limited course and little by way of treatment is needed except for oral rehydration therapy 3
  • Chronic diarrhea poses a longer-term problem and may require long-term symptomatic therapy 3
  • Diarrhea in patients with inflammatory bowel disease requires a wide differential diagnosis to define the pathophysiologic mechanisms in individual patients 4
  • Empiric metronidazole for Clostridium difficile-associated diarrhea should be reserved for strongly presumptive cases 5
  • Metronidazole-kaolin interactions have been studied, and the results suggest a physical interaction between the two 6

Treatment Options

  • Supportive therapy: fluid and electrolyte replacement 2
  • Symptomatic therapy: improves the consistency of the stool and reduces the frequency of bowel movements 2
  • Specific therapy: aimed at treating the cause of diarrhea, such as antibiotics for bacteria-induced diarrhea 2
  • Opiate antidiarrheal drugs: effective for a wide variety of diarrheal conditions, but may have addictive liability 3
  • Loperamide, diphenoxylate, codeine sulfate, and tinctures of opium: slow motility and increase the absorption of fluids and nutrients 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Drug therapy reviews: pharmacotherapy of diarrhea.

American journal of hospital pharmacy, 1979

Research

Antidiarrheal Drug Therapy.

Current gastroenterology reports, 2017

Research

Determination and characterization of metronidazole-kaolin interaction.

Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society, 2015

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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