Skip to Content

Why is my dog throwing up and is lethargic?

It’s common for dogs to throw up occasionally. Perhaps they were digging in the trash, and helped themselves to something they shouldn’t be eating. Perhaps you switched their food, upsetting their digestive system. 

When dogs are vomiting, or vomiting and experiencing diarrhea, but seem fine otherwise, you have little to worry about. However, when they are lethargic and vomiting, this is more concerning. 

Why is my dog throwing up and is lethargic?

Lethargy and vomiting are concerning when they occur together. It indicates a serious health problem. Perhaps you’ve heard the saying, “you can’t keep a good dog down”. 

Dogs are resilient creatures and can seem fine even though they have gastrointestinal issues. If your dog is lethargic and vomiting, this is more concerning than vomiting alone. there are several potential causes. 


Dogs are curious creatures, and they don’t always exercise good judgement. There are many potential toxins, including some human foods. 

Xylitol is highly toxic to dogs. Grapes and chocolate also pose a risk. Household cleaners are another common culprit. Even your seemingly innocent houseplants could be toxic to your pooch. 

When a dog eats something toxic, they will experience vomiting and lethargy. Other potential signs of poisoning include oral irritation, inability to urinate, diarrhea, drooling, and agitation. 

More concerning symptoms include tremors, seizures, and heart problems, and kidney failure. 

 Food Poisoning 

Food poisoning isn’t a common problem for dogs. Their stomach is more acidic than ours, which allows them to kill the bacteria before it can multiply in their digestive system. 

Despite this, it is possible for your dog to get food poisoning. 

In addition to vomiting and lethargy, food poisoning can cause panting, excessive drooling, hyperactivity, uncontrolled peeing, loss of muscle control, and bloody stool. 

Stomach virus

A stomach virus can also cause vomiting and lethargy. This occurs when a bacteria or virus affects your dogs stomach. Other signs include diarrhea, abdominal pain, restlessness, and blood in their poop. 


An intestinal blockage is a rarer cause of vomiting and lethargy in dogs. However, it can be life threatening, so it’s important to know the symptoms. 

It occurs when something is creating a block in your dog’s intestines. This is often a foreign object that they’ve eaten. Severe constipation can also cause a blockage. 

The blockage can be either partial or complete. A partial blockage allows some poop to come out, while a complete blockage blocks all waste from moving through the system. This causes the waste to back up into the intestines. 

Vomitting and lethargy are common signs of an intestinal blockage. Other signs include a loss of appetite, diarrhea, depression, dehydration, and abdominal pain. 

Kidney or Liver Disease

Kidney or liver disease are serious conditions. If caught early, they can be managed to improve your dog’s quality and length of life. Kidney or liver failure are harder to manage, and present more severe symptoms. 

in addition to vomiting and lethargy, these conditions can cause diarrhea, weight loss, behavioral changes, seizures, loss of appetite, and very bad breath.


Parvovirus, commonly known as parvo, is a highly contagious disease. it can affect dogs of any age, but it’s most common in puppies younger than 4 months old. Older dogs are typically vaccinated against parvo. 

The signs of parvo incude vomitting and lethargy. Other symptoms include loss of appetite, abdominal pain, fever or a low temperature. Bloody diarrhea is also common with the disease.  

There’s no medication to kill the parvo virus, so treatment focuses on the symptoms. When caught early, 90% of dogs with aprvo survive. Without treatment, dogs often die within 48 to 72 hours. 


Like parvo, distemper is prevented with vaccinations, but puppies who have not been vaccinated are at a higher risk of contracting the disease. 

Vomitting and lethargy occur with the virus, along with a host of other symptoms. 

It typically begins with Initially, watery or pus discharge from the dogs eyes. Then, the dog wll deveop fever, runny nose, coughing, lethargy, loss of appetite, and vomitting.

The virus will then attack the nervous system. Dogs can develop circling behavior, head tilt, jaw clenching, excessive salivation, and convulsions. They may also develop partial or complete paralysis. 

There’s no cure for distemper. Instead, treatment focuses on symptom management. Dogs who survive typically have lasting damage from the virus.


Parasites can also cause vomiting and lethargy. Heartworms are the most concerning type of parasite that can affect your dog. Symptoms include persistent cough, lethargy, vomiting, weight loss, difficulty breathing, and bulging ribs. 

Intestinal parasites can also cause similar symptoms. These include diarrhea, potentially with blood or mucus, scootting, vomiting, swollen stomach, lethargy, and weight loss. 

What to do if my dog is throwing up and is lethargic?

If your dog is throwing up and lethargic, what you do will depend on the severity of their symptoms, and any other symptoms they may have. 

Mild Symptoms 

If your dog displays mild vomiting and lethargy, you can choose to monitor them at home. They may also have diarrhea, because many gastrointestinal issues can cause both vomiting and diarrhea. 

There are a few things you can do to help your pooch feel better. Pepto can help settle your dog’s stomach. Give them one teaspoon for every 10 pounds of body weight. You can repeat the dose in 6 to 8 hours.

Famotide is an antacid that can also be helpful. You can give your pooch .5 mg per pound of body weight. This can be repeated every 12 hours. 

Lastly, a bland diet is needed until the vomiting stops. Feed them 2 parts rice and 1 part boiled chicken. Continue this diet until symptoms have stopped, and slowly transition them back to their regular food. 

Severe Symptoms

If your dog is having severe vomiting or lethargy, or other symptoms including fever, tremors, or behavioral changes, you should get them to the vet immediately. 

When to see a vet about a dog throwing up and being lethargic

 So some cases of vomiting and lethargy can be treated at home, but others require veterinary care. How do you know when its time to visit the vet?

Cause of Symptoms

If you can identify the cause of the symptoms, this gives you a clue as to whether they need treatment. If they’ve eaten something toxic, they need immediate veterinary care. 

Parvo, distemper, intestinal blockage, liver disease, and heart disease also require immediate veterinary care. Parasites, including heart worm and intestinal parasites, also require a trip to the vet. 

If your pooch’s symptoms have another cause, like food poisoning or a stomach virus, you’ll need to consider the severity of their symptoms. 

Severe Lethargy 

If your dog is too lethargic to eat, drink, or use the bathroom, its an emergency. If they seem very lethargic or have muscle weakness, you should also get them to the vet. 

Severe Vomiting and Dehydration 

If they are vomiting repeatedly, particularly more than 3 times over an 8 hour period, this also requires veterinary care. 

Dehydration is a concern with repeated vomiting. Check for dehydration by looking at your dog’s gums. If they are tacky, sticky, or pale, your pooch is dehydrated. Healthy gums should be pink and moist. 

Another way to check for dehydration is to pinch the skin on your dog’s shoulders. The skin should go back immediately when released. If it doesn’t, your pooch is likely to be dehydrated. 

Blood in Vomit

Blood in your dog’s vomit is concerning. They may also have bloody diarrhea. Because this can indicate very serious conditions, you’ll need to get your pooch to the vet as soon as possible. 

Other Concerning Symptoms

Fever is another sign that something is wrong. Dog’s normal body temperature is 101-102.5. A temperature of 103 is considered a fever. If their temp reaches 106, this is an emergency. 

Some diseases and conditions can cause difficulty breathing. This is very concerning, and should be evaluated by a vet. 

Serious symptoms like seizures, tremors, or disorientation also require immediate care.