Dog Diarrhea And Thirsty? Here’s What It Means

If your dog has diarrhea and is thirsty at the same time, we outline the potential causes of dog diarrhea and thirst, as well as what to do and when to seek help. 

Here’s why dog diarrhea and thirst occurs

Dog diarrhea and thirst occur due to dehydration because of a number of illnesses and health issues that cause diarrhea which include gastrointestinal infections, diet, medication side effects, illness, stress, and poisoning.

Dog diarrhea and thirsty

Dog diarrhea and thirst

Dog diarrhea is a condition in which a dog’s stool is loose and watery, and which they pass more frequently than normal. This can cause a dog’s body to lose a lot of fluid, potentially leading to dehydration.

Occasional episodes of diarrhea in dogs are common and normal, however, frequent diarrhea as well as other concerning symptoms can be a sign of a serious underlying problem.

Thirst in dogs refers to the need or desire to drink water. It is a natural response to dehydration or a lack of fluids in a dog’s body. 

Thirst can be triggered by different factors, including physical activity, hot weather, illness, or dry food diets. 

Common signs of thirst in dogs include:

  • Panting
  • Smacking or licking of lips
  • Lethargy
  • Dry mouth
  • Sunken eyes
  • Seeking out water
  • Dry sticky gums
  • Dry nose
  • Vomiting with or without diarrhea

Thirst and diarrhea happening at the same time can be due to a variety of causes. In most cases, these symptoms are accompanied by other behavior changes and symptoms.

Related: Dog diarrhea and excessive peeing (Explained)

Possible causes of dog diarrhea and thirst

Thirst sometimes occurs alongside dog diarrhea. A dog may experience both diarrhea and thirst as a result of an underlying condition. 

Severe thirst and diarrhea in a dog may indicate a disease or a more serious medical issue.

The possible causes of diarrhea and thirst are:

Gastrointestinal infection

Gastrointestinal infection by bacteria, intestinal parasites, or viruses is the most common cause of diarrhea and thirst in a dog.

Gastrointestinal infections can lead to thirst in dogs by causing vomiting and diarrhea, which can result in fluid loss and dehydration. 

A dehydrated dog feels thirsty as their body creates the urge to drink water to replace the lost fluids. 

Change in diet

A change in your dog’s diet can cause diarrhea and thirst due to food intolerance or allergy, an upset stomach, and the type of food they consume can affect their water intake and hydration levels.

This is because it takes time for your dog’s stomach to adjust to the new food and a sudden change to a new food may cause diarrhea. 

In addition to causing diarrhea, some foods, especially those that are high in sodium, can increase a dog’s thirst and cause them to drink more water.

If a dog’s new diet contains less water content than their previous diet, they may also feel a need to drink more water. For example, if a dog switches from wet to dry food, they may feel a need to drink more water.

To avoid these problems, it is important to introduce changes to your dog’s diet gradually, over the course of several days or weeks, to give their digestive system time to adjust.

Also, it is important to choose a high-quality, nutritionally balanced dog food that meets your dog’s individual needs.


Diarrhea and thirst can be symptoms of a wide range of illnesses in dogs, including viral or bacterial infections, gastrointestinal disorders, and systemic diseases.

When a dog is sick, they may experience symptoms such as vomiting, diarrhea, fever, or excessive panting, which can cause them to lose fluids which causes dehydration.

In response to this loss of fluids, a dog’s body triggers thirst to encourage them to drink more water and rehydrate. 

Some illnesses may cause a dog’s body to produce more urine, which can also lead to increased thirst in an effort for the body to replace the lost fluids.


A stressed dog also experiences diarrhea including thirst, which may appear at the same time. Stress can come from different of sources such as a change in their environment or routine, new people or pets, loud noises, and other fear-related stressful situations.

Stress can lead to thirst in dogs because their body’s response to stress can trigger an increase in fluid loss and dehydration. 

When a dog is stressed, their body produces stress hormones which cause an increase in the heart rate and breathing rate, leading to excessive panting and sweating.

This increased panting and sweating causes a dog to lose fluids and become dehydrated. In response to this, a dog may feel thirsty and have the need to drink more water to restore the fluids lost due to stress.

Stress can also affect a dog’s appetite which can lead to behavior changes in their food and water intake. This means a stressed dog may eat less and also drink less water resulting in thirst.

Stress and anxiety also cause a variety of symptoms including pacing, licking, drooling, yawning, crying, barking, and hiding.

Side effects of medication 

Medications can sometimes cause side effects in dogs, including diarrhea and thirst which may happen at the same time.

The side effects can occur due to irritation of the digestive tract and allergic reactions which causes diarrhea.

Some medications can cause dehydration or increase a dog’s need to drink water. For example, medications such as diuretics can increase urine production which causes a dog to lose more fluids, leading to dehydration.

Also, certain medications can cause a dog to have an increased appetite and a dry mouth which increases a dog’s thirst sensation, leading to a need to drink lots of water. 


Poisoning in dogs can lead to a variety of symptoms, including diarrhea and thirst. This is because many poisons and toxins can cause gastrointestinal upset and also thirst because certain toxins can cause dehydration, leading to an increase in the dog’s need for water.

When a dog is poisoned, their body responds by trying to remove the toxin, which can lead to vomiting, diarrhea, or increased urination.

These symptoms can cause a dog to lose electrolytes and fluids which leads to dehydration. In response to this, a dog may feel thirsty and need to drink more water to replace the fluids lost due to poisoning.

Some toxins can also cause damage to a dog’s organs, such as the liver or kidneys, which can affect their ability to regulate water and electrolyte levels in their body. This can lead to an increase in thirst as the body tries to maintain hydration.

Dogs may accidentally ingest toxic substances such as household cleaners, contaminated food or water, pesticides, insecticides, poisonous plants or human medications, which can cause diarrhea and other symptoms.

Dog diarrhea and thirst: What to do and when to seek help

If your dog is experiencing both diarrhea and thirst, it is important to seek veterinary care as soon as possible. 

Here are  other signs that indicate that you should see a veterinarian immediately:

Severe or bloody diarrhea: If your dog’s diarrhea is severe or if there is blood or mucus in the stool, this could be a sign of a serious underlying condition and requires immediate veterinary attention.

Other symptoms: Other symptoms may accompany diarrhea and thirst, such as vomiting. If your dog is vomiting along with diarrhea, this can lead to dehydration and other complications and requires immediate medical attention. 

Other symptoms to look out for include lethargy, lack of appetite, breathing difficulties, signs of pain or discomfort, fever, fainting, seizures, rapid heart rate, and difficulty in walking.

Suspicion poisoning: If you suspect that your dog has been poisoned, it is important to seek veterinary care immediately.

If your dog is a puppy or an older dog: Puppies and older are generally more vulnerable than healthy adult dogs so delaying treatment could result in their condition worsening or becoming more difficult to treat. Therefore, it is essential to seek immediate medical care.

Key Takeaway: Dog diarrhea and thirst

Diarrhea and thirst in dogs can be caused by a variety of factors.  While occasional diarrhea is normal in dogs, persistent diarrhea alongside other symptoms such as thirst requires veterinary attention.

If you notice your dog showing these symptoms suddenly or for extended periods of time, consult with your veterinarian to determine the underlying cause and appropriate treatment. 

By addressing the underlying cause of the symptoms and providing appropriate care, you can help ensure that your dog remains healthy.

Dog diarrhea doesn’t have to be a source of stress. Our comprehensive guide on dog diarrhea is here to empower you with knowledge and practical solutions. Visit the article to access a wealth of information and learn how to effectively manage dog diarrhea.