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Shih Tzu With Diarrhea: 7 Causes & What To Do Next

If your Shih Tzu has diarrhea it can be both worrying and confusing. What caused it, and how can you help them?

Thankfully I’ve successfully helped thousands of owners recover their dogs from diarrhea in no time at all.

That’s why I’m here to help you better understand the possible causes of this common issue and share some tips on how to help your Shih Tzu feel better.

Let’s dive in!

shih tzu diarrhea

7 Reasons Your Shih Tzu Has Diarrhea

Knowing which one of the following applies to your Shih Tzu will take a little detective work.

Owners will need to think about the recent events leading up to this moment, your Shih Tzu’s movements and actions, and their overall routine in the recent days.

Consider that, check out the following, and it might quickly become obvious what has happened.

1. Digestive Upset

Digestive upset is a common cause of diarrhea in Shih Tzus. In fact, this is likely the no.1 reason and constitutes a few main things…

It can be triggered by:

  • Overeating
  • Eating something spoiled or toxic
  • Eating something foul while outside in public or your yard
  • Eating human food
  • Food allergies or intolerances

Identifying the cause: Monitor your Shih Tzu’s eating habits and note any changes in their diet or environment that could have led to the digestive upset.

How to help: If you suspect your Shih Tzu has eaten something harmful, contact your veterinarian immediately. For food allergies or intolerances, work with your vet to identify the culprit and adjust their diet accordingly.

2. Switching Kibble or Low-Quality Kibble

Switching your Shih Tzu’s kibble too quickly or feeding them a low-quality diet can lead to diarrhea.

Identifying the cause: If you’ve recently changed your Shih Tzu’s kibble or started feeding them a new brand, this could be the cause of their diarrhea.

How to help: Gradually transition your dog to a new kibble by mixing it with their old food over 7-10 days. Choose a high-quality dog food that meets the nutritional guidelines set by the AAFCO. Consult your vet for recommendations specific to your Shih Tzu’s needs.

3. Stress & Anxiety

Just like humans, Shih Tzus can experience stress and anxiety, which can manifest as diarrhea. Common stressors include:

  • Changes in routine or environment
  • Loud noises (fireworks, thunderstorms)
  • Separation anxiety

Identifying the cause: Note any recent changes in your Shih Tzu’s life that could be causing stress or anxiety.

How to help : Minimize the stressors and create a calm, comforting environment for your dog. Consider using calming aids like pheromone diffusers or anxiety vests, and consult your vet for further recommendations.

4. Bacterial Infections

Bacterial infections, such as Salmonella or E. coli, can cause diarrhea in Shih Tzus. They can contract these infections by consuming contaminated food, water, or feces.

Identifying the cause: If your Shih Tzu has a bacterial infection, they may also exhibit symptoms like vomiting, fever, or lethargy.

How to help: Contact your veterinarian, who may prescribe antibiotics to treat the infection.

5. Parasites

Parasites like roundworms, hookworms, and giardia can cause diarrhea in Shih Tzus. They can contract these parasites by ingesting contaminated soil, water, or feces.

Identifying the cause: If your Shih Tzu has parasites, they may also have other symptoms like weight loss, vomiting, or a bloated abdomen.

How to help: Consult your vet for a proper diagnosis and treatment plan, which may include deworming medications.

6. Dehydration or Heatstroke

Dehydration or heatstroke can cause diarrhea in Shih Tzus, especially during hot weather or after intense exercise.

Identifying the cause: Look for signs of dehydration, such as sunken eyes, dry nose and gums, and lethargy. Heatstroke symptoms may include excessive panting, drooling, and vomiting.

How to help: If you suspect dehydration or heatstroke, move your Shih Tzu to a cool, shaded area and offer them small amounts of water. Contact your veterinarian for further guidance and treatment.

7. Health Issues or Medications

Underlying health issues, such as liver or kidney disease, can cause diarrhea in Shih Tzus. Additionally, certain medications, like antibiotics or nonsteroidal anti-inflammatory drugs (NSAIDs), can lead to gastrointestinal upset.

Identifying the cause: Review your Shih Tzu’s medical history and any medications they’re currently taking.

How to help: Consult your veterinarian to determine if the diarrhea is related to an underlying health issue or a side effect of medication. They can recommend appropriate adjustments to your dog’s treatment plan.

When to See a Veterinarian

It’s important to consult your veterinarian if your Shih Tzu’s diarrhea:

  • Persists for more than 24 hours
  • Is accompanied by vomiting, fever, or lethargy
  • Contains blood or black, tarry stools

These symptoms could indicate a more serious issue that requires prompt medical attention.

How to Help Your Shih Tzu with Diarrhea

Once you’ve identified the cause of your Shih Tzu’s diarrhea, there are several ways to help them feel better:

1. Fasting

Fasting can be an effective way to allow your Shih Tzu’s digestive system to rest and recover. During this time, your dog’s body can focus on clearing out any irritants or toxins that may be causing diarrhea. It’s important to consult your veterinarian before starting a fasting period, as it may not be appropriate for all dogs. A fasting period should generally last between 12-24 hours. Make sure to provide fresh water throughout the fasting period to prevent dehydration.

It’s not advised for puppies (under 1) or seniors (over 8) to fast.

2. Bland food diet

After the fasting period (if appropriate), gradually reintroduce food to your Shih Tzu by offering a bland diet. A bland diet typically consists of boiled chicken (skinless and boneless) and white rice. You can also use boiled turkey or ground beef, but make sure to drain any excess fat. The bland diet should be fed in small amounts, about 4-6 times per day, for a few days. Keep an eye on your dog’s stool consistency, and once it begins to firm up, gradually transition back to their regular diet over the course of 5-7 days.

3. Antidiarrheal medication

Over-the-counter antidiarrheal medications, like Imodium (loperamide), can help alleviate diarrhea in some cases. However, it’s important to consult your veterinarian before administering any medication to your Shih Tzu, as certain medications may not be suitable for all dogs or could cause adverse effects. Your vet will provide guidance on the appropriate medication, dosage, and duration of treatment based on your dog’s specific needs.

4. Probiotics

Probiotics are beneficial bacteria that can help support your Shih Tzu’s digestive health. They can aid in the restoration of the natural balance of gut flora, which may be disrupted due to diarrhea. Probiotics are available in various forms, such as capsules, powders, or chews, and can be found at pet stores or through your veterinarian. It’s important to choose a probiotic supplement specifically formulated for dogs and to follow the recommended dosage guidelines. Consult your vet for recommendations on the best product for your Shih Tzu and for guidance on proper usage.

Remember that each Shih Tzu is unique, and their needs may vary. Always consult your veterinarian for personalized advice and recommendations tailored to your dog’s specific situation.

Tips for Preventing Diarrhea in the Future

To minimize the risk of diarrhea in your Shih Tzu, follow these tips:

  • Feed a high-quality diet that meets AAFCO guidelines
  • Avoid sudden changes in kibble
  • Limit access to potentially harmful foods, substances, or contaminated areas
  • Provide fresh water at all times
  • Practice regular parasite prevention, as advised by your vet
  • Keep your Shih Tzu’s environment clean and stress-free
  • Schedule regular veterinary checkups to monitor your dog’s health

By understanding the potential causes of diarrhea in Shih Tzus and knowing how to help, you can ensure your furry friend stays happy and healthy. Don’t hesitate to consult your veterinarian if you have any concerns or questions about your Shih Tzu’s health.


Before making any decisions that could affect the health and/or safety of your dog, you should always consult a trained veterinarian in your local area. Even though this content may have been written/reviewed by a trained veterinarian, our advice to you is to always consult your own local veterinarian in person. Please read our full dislcaimer if you have any questions.