lethargic dog with labored breathing
Pet Health Questions and Answers

Why is My Dog Lethargic and Not Eating or Drinking?

Is your dog suddenly lethargic? Do they have other symptoms that seem strange to you? Perhaps they’re not eating or drinking, or maybe they even look sick. Although scary, it’s not always a cause for serious concern. But, there are many factors to consider.

If your dog is acting strangely, you need to check for any other symptoms. Is your dog shaking or breathing heavily? Do they look sad? You may be able to self-treat your dog at home or make lifestyle changes. Other health issues may require veterinary attention or long-term care.

Most dogs sleep for around ten hours a day, so noticing sudden changes can be hard at first. There’s a difference between being genuinely tired and feeling lethargic. Seeing those signs and treating the underlying cause of lethargy is vital to the recovery of your pet.

What Should I Do if My Dog is Lethargic and Not Himself?

Signs of lethargy include not eating or drinking. Your dog may not come to you when you call them, and they might not want to play or exercise. Most pet owners know that there’s a problem when their dog doesn’t have their usual personality.

This guide will focus on different reasons why your dog might be lethargic. It could be an underlying illness that needs immediate medical care, so recognizing the other symptoms and tackling them right away is essential.

What Are the Signs of Lethargy in Dogs?

Most people associate lethargy with a dog just being tired and lazy. But, there’s more to it than that. You may start to wonder if your dog is just tired or depressed. There are other signs you can look for that suggest lethargy.

These signs can make it more transparent that something may be wrong with your pet. Knowing the difference between general tiredness and a dog that’s lethargic can help guide you toward getting the right treatment significantly sooner.

Some of the signs of lethargy in dogs include:

  • Sleeping for an extended period of time
  • Eyes glazed over
  • Looking dazed
  • Confusion
  • Lack of energy
  • Delayed response to things around them
  • May not respond when you call them
  • Gives up food and water to sleep instead

Sometimes, dogs can be a little more lethargic after a long day of playing or exercise. Sometimes, a bug or virus can get to them, like the flu. This can make them seem different for a few days. But, consistent symptoms are much different.

If your dog’s behavior doesn’t change in a day or two, it’s time to explore the possible causes.

What Are the Symptoms of Sickness in Dogs?

One of the main reasons your dog might be suddenly lethargic is a sickness. This is a broad category, of course. Sickness could be something as simple as an upset stomach, or something more serious.

If your dog is lethargic and shaking, it could be a good sign that they’re in pain, likely due to an internal issue. Let’s explore the common types of illness your dog can face that may cause lethargy.

Fever and Infection

According to the American Kennel Club, the average temperature for a dog is 97.6-99.6. If it isn’t in that range, your dog may have a fever. Many medical factors can cause a fever, including a bacterial or viral illness or an infection.

Several serious infections affect dogs:

  • Parvovirus: This can cause your dog to be lethargic and vomiting. It can also lead to severe diarrhea and abdominal pain. It’s spread through feces, so if your dog ingests another dog’s (or their own) feces, it can be easy to contract. Thankfully, it’s treatable with fluids and anti-nausea medication. A vet may also put them on antibiotics to completely remove the virus from their system.
  • Distemper: This can cause lethargy and fever in dogs. It also can cause everything from coughing to neurological problems. This can be a tough condition to diagnose on your own because symptoms vary so much from dog to dog. It’s best to get a diagnosis from a vet. Treatment usually includes antibiotics.
  • Heart disease: If your dog is lethargic and not eating or drinking, he may have heart disease. Other symptoms include a lack of exercise and trouble breathing. Treatment depends on the severity of the condition, ranging from dietary changes to heart medication.
  • Liver disease: If your dog has liver disease you may wonder ‘is my puppy sick or just tired?’. If your dog seems sad and tired, or depressed, it could be a symptom of a liver condition.
  • Kennel Cough: If your dog is frequently around other dogs, kennel cough could become a serious issue. They could pick it up at a park, kennel, doggy daycare, etc. As you might expect from the name, the most noticeable symptom is a dry cough. Normally, kennel cough can be treated with antibiotics and cough suppressants.

A fever can also be caused by ingesting poison or another foreign substance that can make your dog sick. If your dog won’t eat or drink and is weak, you may also want to check their temperature, as this can be a sign of a fever.

my dog wont eat or drink and is vomiting


There are different types of trauma that a dog can experience, just like people. Your pet can go through both physical and emotional trauma. There are signs to look for when it comes to each.

Physical trauma is often much simpler to identify. You probably know if your dog has gone through something physically damaging. Many other symptoms can go along with physical trauma, such as a lasting pain from an injury.

Physical trauma that leads to lethargy, shaking and sickness might mean there is a more severe problem. Take your dog to the vet if they experience a sudden physical trauma and it lasts for over 24 hours. There could be issues like internal bleeding, fractures or breaks, etc.

Emotional trauma can sometimes be harder to diagnose on your own. But, there are signs that you need to know.

Along with lethargy, emotional trauma often comes with the following symptoms:

  • Behavioral disorders
  • Anxiety
  • Hiding
  • Jumping up on people
  • Fidgeting
  • Shaking
  • Urinating or defecating in the house
  • Pacing
  • Panting
  • Depression

You know your pet better than anyone. So, you’re bound to pick up on some of these sudden changes or behavioral issues quickly. If your dog isn’t acting like themselves, it could be due to emotional trauma. This could be anything from abuse to lifestyle changes.

The most common treatment for emotional trauma is desensitization. This is a process that conditions your dog to eventually not fear whatever may trigger their trauma. In fact, they may finally see the trigger as a positive thing.

Your dog may be scared or nervous about something. New puppies or dogs newly introduced into your home can feel anxious and afraid. If your dog is breathing heavy and throwing up, or if they are a lethargic dog with labored breathing, it could be nerves.

If there has been a sudden change in their lives, do what you can to put them at ease. Spend more time with them, be calm around them, give them attention, etc. This could take some time, so it’s vital to be patient.

But, there is no real ‘treatment’ for a dog that’s nervous about change aside from time, patience, and reassurance.

Reacting to Medications

Medications are designed to make dogs feel better, but they can sometimes have side effects. One common side effect of many different medications is lethargy. Medicines can cause your dog to start acting lazy or depressed. They can also cause your dog not to eat, even if they’re still drinking. There are so many potential side effects of meds that it’s literally impossible to list them all.

Thankfully, it can be reasonably easy to determine if your pet’s lethargy is due to their medication. If it’s a prescription they’ve been on for a while with no previous symptoms, it’s likely to be something else that’s causing their lethargic behavior.

But, if the new behavior started after a new medication or a changed prescription, it’s reasonable to make that connection. In fact, sometimes lethargy may be one of the only outward side effects that shows up after a new medication.

So, it’s important to pay attention to your dog and make sure they are acting like themselves if they switch their medicine. If they start behaving differently, it’s a good idea to call your vet about the problem. Some symptoms may not last long. Others could be causing internal damage that you wouldn’t notice.

You should never give your dog a medication that’s intended for humans. Things like Ibuprofen or aspirin can be poisonous to dogs and do more harm than good. Always talk to your vet about the right kind of medication for any condition your dog might be facing.

dog shivering and not eating


A toxic reaction can occur if your dog gains access to something that they shouldn’t. Some kinds of poisoning are obvious. There are certain substances no animal should consume.

Things like certain medications, cleaning supplies, or antifreeze are obvious causes. But, dogs can also experience a toxic reaction from certain foods or plants. They can also experience a reaction from something like a bug bite or sting.

You need to know what’s caused the poisoning in your dog so you can get them the proper treatment. No matter what it was, though, most symptoms of a toxic reaction are similar.

The most common ones include:

  • Vomiting
  • Shaking/shivering
  • Excessive drooling
  • Loss of appetite
  • Not drinking
  • Drinking excessively
  • Diarrhea
  • Tremors
  • Labored breathing

If these symptoms last for too long, they can have dire consequences. Poisoning can lead to things like unconsciousness or even death. It’s a difficult thing to think about, but that confirms how important it is to get your dog the care they need right away.

Poisoning of any kind needs immediate attention and care. Call your vet if you suspect your dog has ingested something. If you know what they got into, you can tell your vet right away so they can form the best treatment plan possible.

In the meantime, your vet may encourage things you can do at home to help your dog get the poison out of their system, such as inducing vomiting. But, once your dog is stable, they need professional medical attention.

Poor Nutrition

Just like humans, dogs need the right nutrition to lead a happy, healthy, active life.

Eating the wrong kinds of foods can drag down their energy and make them feel lethargic and lazy. When food is the cause of your dog’s lack of energy, it’s usually a sign that what they’re eating doesn’t have all the nutrients they need.

A vitamin deficiency is usually the most common problem with poor nutrition. If your dog is showing signs of lethargy, but no other severe symptoms, it may be something as simple as changing their food.

Be sure to look for food with meat as the first ingredient. It should also have a good balance of proteins, carbs, and fats. If your dog won’t eat but will drink water, they may not like their food and could be seeking out something else.

If you aren’t sure about the kind of nutrition your dog should be receiving, talk with your veterinarian. Sometimes, dogs need a specific nutrition plan put in place. Different breeds need different foods to stay in top shape and remain healthy.

There are certain health conditions connected to your dog’s nutrition, and they can also cause symptoms associated with lethargy.

Two of the most common conditions are as follows:

  • Canine diabetes: It happens when your dog’s blood sugar levels are too high, which can be a result of a poor diet. Other symptoms include weight loss and excessive thirst.
  • Hypoglycemia: This is a condition that occurs when your dog’s sugar levels are too low. This can make your dog so weak and lethargic that it can even trigger seizures. In turn, the seizures can cause even more lethargy.

Diet changes can often help with these conditions. But, in more severe cases, certain medications may be needed to balance out your dog’s blood sugar levels and control the adverse symptoms.

Dehydration can also cause your dog to appear lethargic. Keeping your dog healthy isn’t just about the food you give them. It’s equally important to make sure they stay properly-hydrated at all times.

A dog that won’t eat or drink and is weak can be a sad sight. Once you’re sure it isn’t caused by a health issue, make sure you’re giving them the right kind of food and enough water to keep them satisfied.

Why is My Puppy Lethargic?

Believe it or not, even young dogs can seem lethargic. Unfortunately, lethargy in puppies is usually a sign of something more serious going on. In most cases, it’s linked to a virus or parasite. These include ticks, fleas, heartworms, and hookworms.

Many parasites can be treated, and you can help your puppy get rid of them with the right kind of medication and treatment plan.

Young dogs can even experience more severe conditions like heart failure or pneumonia. In these cases, medical treatment is necessary. Young dogs can experience some of the same symptoms as older dogs if they have these diseases.

Some other common signs aside from a lack of energy include:

  • Vomiting
  • Diarrhea
  • Fever
  • Pain
  • Not eating or drinking
  • Shaking

Lethargy in Senior Dogs

You might expect older dogs to be more lethargic. This can be true sometimes. Dogs, like people, can slow down and have less energy as they age. But, there’s a difference between being tired and showing signs of lethargy.

Unfortunately, senior dogs can also face other issues that can make them seem lethargic.

Some health conditions that are often associated with older dogs include:

  • Cancer
  • Oral diseases
  • Hip dysplasia
  • Glaucoma
  • Urinary tract infections
  • Ear infections

If your dog just seems tired, it could be as simple as that! But, if they have any of the other symptoms, it’s vital to get them the medical treatment they need as soon as possible. Don’t wait days to see if your dog will get better if they’re doing things like vomiting, or not eating.

If they aren’t showing any other signs of distress and everything else seems normal, they could just be going through a short lack of energy. But, now you know what to do if they do exhibit other symptoms. You know your dog’s behaviors better than anyone. So, it’s up to you to make sure they get the care they need if they start to act lethargic and not well.