Is Your Dog Throwing Up and Lethargic? Here’s What You Need to Know

It is incredibly distressing to see your dog feeling unwell. If your dog is throwing up and lethargic, it’s natural to feel worried and unsure of what to do.

Is it an emergency case? And what can cause a dog to vomit and be lethargic?

If your dog has vomiting and lethargic at the same time, we outline the potential causes of dog vomiting and lethargy, as well as what to do and when to seek help.

Why is my dog lethargic and vomiting?

Dog vomiting and lethargy are symptoms that commonly occur together and can be caused by a number of illnesses and disorders which includes gastrointestinal infections, illness, diet, medication side effects, stress, and poisoning.

Dog throwing up and lethargic

Dog throwing up and lethargic

Lethargy in dogs is characterized by a lack of energy, weakness, and an overall feeling of tiredness. 

Dogs that are lethargic may sleep more than usual, have a decreased interest in play or exercise, and have a slower response to stimuli. 

Signs of lethargy in a dog manifests as a lack of interest in activities that they previously enjoyed, such as playing or going for walks, and can also be accompanied by a lack of appetite, and difficulty standing or moving.

It can be a symptom of an underlying condition, both acute and chronic conditions.

Vomiting or throwing up is the forceful expulsion of the stomach contents or upper intestines. This means when a dog vomits, the stomach contents are brought back from the stomach into the esophagus and mouth as either digested, partly digested, or undigested food.

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

Vomiting and lethargy happening at the same time can be due to a variety of causes. In most cases, these symptoms are accompanied by other symptoms such as drooling, loss of appetite, and fever.

Is it normal for a dog to be lethargic after vomiting?

It is not normal for dogs to vomit and become lethargic. While it is not uncommon for dogs to vomit occasionally, especially if they have ingested something they shouldn’t have, persistent or recurrent vomiting and lethargy are not normal and indicate an underlying health problem.

Possible causes of throwing up and lethargy in dogs

Vomiting and lethargy occurring at the same time can have a variety of causes due to an underlying condition. 

The possible causes of dog throwing up and lethargy include:


Vomiting and lethargy 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, their body also uses energy in order to fight the illness. This can lead to a lack of energy and enthusiasm, which manifests as lethargy.

Some illnesses cause physical pain or discomfort which can make them lethargic and unwilling to move around or engage in any physical activity. Certain illnesses also cause weakness or fatigue. 

Related: Dog throwing up and tremors: Here’s why

Gastrointestinal infection

Gastrointestinal infections by bacteria, viruses, or intestinal parasites, are the most common causes of vomiting and lethargy in dogs.

Infections of the digestive tract cause inflammation and irritation, leading to vomiting and lethargy. Some common symptoms of gastrointestinal infections include diarrhea and loss of appetite.

Gastrointestinal infections can cause abdominal discomfort and pain, which makes them lethargic and unwilling to move around or engage in any physical activity

Vomiting with or without diarrhea due to gastrointestinal infection can cause a dog to lose fluids and electrolytes rapidly, leading to dehydration and an electrolyte imbalance. This affects their energy levels resulting in lethargy.

Infection can also cause a loss of appetite which can cause lethargy because of a lack of intake of food to provide energy.

Change in diet

A change in your dog’s diet can cause vomiting and lethargy due to food intolerance or allergy, an upset stomach, and stress.

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 vomiting. 

Dogs are also sensitive to changes in their routine and environment, and a sudden change in diet can be stressful. This stress can lead to digestive upset and other symptoms such as vomiting and lethargy.

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.


A stressed dog also experiences vomiting including lethargy, which may appear at the same time.

A dog’s stomach can get upset when they are stressed or anxious, which causes vomiting or diarrhea among other symptoms.

Stress can cause a  dog to become mentally and emotionally fatigued, which can lead to lethargy which is manifested as a lack of motivation to engage in activities.

Some dogs may experience a loss of appetite or digestive upset when they are stressed, leading to less eating which results in decreased energy levels and weakness.

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

Stress can come from a variety of sources such as a change in their environment or routine, new people or pets, loud noises, and other fear-related stressful situations.

Toxin ingestion

Poisoning in dogs can lead to a variety of symptoms, including vomiting and lethargy. This is because many poisons and toxins can cause gastrointestinal upset leading to vomiting.

Depending on the substance that the dog has ingested, the toxic effects from ingested toxins can lead to a decrease in energy levels and overall lethargy.

Some toxins can directly affect a dog’s central nervous system, leading to weakness, tremors, or seizures. 

Other toxins may affect the liver or other organs, leading to metabolic imbalances and decreased energy levels.

Vomiting and/or diarrhea caused by ingestion of a toxic substance can lead to dehydration and electrolyte imbalance which causes lethargy.

Poisons may also affect a dog’s appetite which makes them eat less or not all, which also leads to lethargy.

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

Side effects of medication

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

The side effects can occur due to irritation of the digestive tract, and allergic reaction which causes vomiting.

Medications can also cause lethargy due to their effects. Some medications cause drowsiness or sedation as a side effect, leading to lethargy. 

Other medications can affect a dog’s metabolism, leading to decreased energy levels and weakness. 

In addition to vomiting, some medications can also affect a dog’s appetite leading to a decrease in food intake and energy levels.

Dietary indiscretion

Dietary indiscretion refers to eating non-food items or food that is not part of a dog’s regular diet. This can lead to diarrhea, vomiting, lethargy, stomach pain, dehydration, and flatulence due to an upset stomach, bacterial or viral infection, gastrointestinal obstruction, and stress.

Ingestion of foreign items can cause vomiting and diarrhea which can lead to dehydration and electrolyte imbalances which in turn causes lethargy.

Also, if a dog has eaten something that is difficult to digest which leads to a blockage in the digestive system, this can cause pain and discomfort, which in turn leads to lethargy.

Dogs may eat non-food items or consume food outside of their regular diet due to stress or anxiety, which can also lead to digestive upset, vomiting, and other symptoms such as lethargy.

What to do when your dog is vomiting and lethargic

If your dog is throwing up and is lethargic, 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 vomiting: If your dog’s vomiting is severe or if there is blood in the vomit, this could be a sign of a serious underlying condition and requires immediate veterinary attention.

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

Other symptoms to look out for include lack of appetite, breathing difficulties, signs of pain or discomfort, fever, and signs of dehydration, such as a dry nose or mouth and sunken eyes.

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: A puppy throwing up and lethargic is an emergency case as well as senior dogs in the same state

Puppies and older dogs 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.

See Also: Dog throwing up, diarrhea, and shaking: Find out why

Key Takeaway: Dog throwing up and lethargic

If your dog throws up and is lethargic immediately consult your veterinarian. These symptoms can indicate an underlying health problem.

While occasional vomiting is normal in dogs, persistent vomiting alongside other symptoms such as lethargy requires veterinary attention.

If you notice your dog showing these symptoms suddenly, 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 recovers.