What are the common causes of chronic diarrhea in dogs?

Common causes include dietary intolerance or recent food changes, parasites, chronic infection, intestinal inflammation (such as inflammatory bowel disease), or metabolic disorders. A vet examination is needed to confirm the underlying cause.

What tests are typically done at the clinic?

Common tests include blood work, urinalysis, fecal examination, abdominal X-ray or ultrasound, and — if needed — molecular testing (PCR) or endoscopic tissue sampling.

What home care and records can I provide?

You can record vomiting and bowel movement frequency, photograph stools, weigh your dog weekly, and observe energy levels and water intake. All of this information helps your vet make a more accurate assessment.

When is it safe to monitor at home, and when should I see a vet?

Mild, short-term diarrhea can be observed and recorded at home, but if your dog is vomiting, has blood in the stool, seems unusually lethargic, or symptoms persist beyond two weeks, you should see a vet promptly.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Chronic Diarrhea in Dogs: Symptoms, Diagnosis & Home Care [2025]

Chronic diarrhea in dogs requires systematic investigation to identify the underlying cause, which may include parasites, infection, inflammatory bowel disease, or tumors. Treatment depends on the diagnosis and may involve dietary changes, medication, or surgery.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: AVMA, WSAVA, National Taiwan University Veterinary Teaching Hospital

When to See a Vet

Seek Emergency Care Immediately

•Persistent, heavy vomiting with inability to keep fluids down
•Black, tarry stools or obvious bloody stool
•Marked lethargy or significantly reduced responsiveness requiring immediate attention

Schedule a Clinic Visit Soon (within 24–72 hours)

•Diarrhea lasting more than two weeks or recurring repeatedly
•Ongoing weight loss with no obvious cause
•Increased thirst or noticeably reduced skin elasticity

01What symptoms indicate something is wrong?

Dogs with chronic diarrhea often show recurring loose stools alongside gastrointestinal or systemic signs. Any persistent changes should be evaluated promptly.

Diarrhea lasting more than two weeks or recurring repeatedly
Frequent vomiting or vomiting accompanied by changes in appetite
Unexplained gradual weight loss that warrants attention
Black, tarry stools or blood in the stool — record and report
Increased thirst and reduced skin elasticity suggesting dehydration
Noticeable increase or decrease in food intake or changes in eating habits
Arrange a vet visit promptly if symptoms persist or worsen

Seek emergency care immediately if you notice the following symptoms:

⚠️ Persistent heavy vomiting with inability to keep fluids down
⚠️ Black, tarry stools or obvious blood in the stool
⚠️ Marked lethargy or decreased responsiveness — seek veterinary care immediately

02How to assess the situation at home? Key observations and when to seek emergency care

Observing and recording key information at home can speed up clinical assessment and diagnosis.

Record the frequency of vomiting and describe the contents each time
Photograph stools and note the time and consistency
Weigh your dog weekly and track any changes in body weight
Monitor energy levels, activity, and any changes in sleep patterns
Record food type, treats given, and any changes in the amount eaten
Bring photos and records to the appointment to help your vet make a faster assessment

03How will the vet diagnose the problem? Common diagnostic tests

At the clinic, the vet will take a full history, perform a physical examination, and arrange appropriate tests to identify the cause of the diarrhea.

Blood and urine tests

to assess electrolytes, organ function, and infection markers

Abdominal X-ray

to evaluate intestinal gas distribution and check for obstruction or foreign bodies

Abdominal ultrasound

to examine intestinal wall thickness, enlargement, or intestinal contents

Fecal examination and culture

to identify parasites or pathogenic bacteria

Molecular testing (PCR) or parasite testing

to detect specific pathogens

Endoscopy or biopsy

to obtain tissue samples for a definitive diagnosis when needed

Referral to a specialist clinic with endoscopy and biopsy capabilities is recommended for further evaluation

04How is the condition treated and managed? Medications, diet changes, and care guide

Treatment is tailored to the test results, and follow-up examinations are scheduled to assess response and recovery.

Dogs with acute dehydration may require in-hospital fluid support and short-term monitoring
Medications and follow-up treatment plans are adjusted based on test results
Prescription diets or elimination diet trials may be used to identify food-related factors
Regular check-ups are needed to monitor symptoms and review blood or imaging results
Home care focuses on maintaining hydration, feeding smaller meals, and tracking bowel movements
If symptoms do not improve or recur, referral to a specialist hospital is recommended

05What should you prepare before the vet visit? Key information to help your vet diagnose quickly

Take photos of any vomit and stools, noting the time each occurred

Record the date symptoms first appeared, how they progressed, and how long they have lasted

List recent food, treats, and all medications or supplements currently being given

Note daily water intake, frequency of urination, and any changes in energy or activity

Weekly weight records and any information about rapid weight changes

It is recommended to bring all records to a specialist clinic with advanced diagnostic capabilities

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.