Lethargy in Dogs

Written By Darlene Stott
Published: 06/11/2017Updated: 03/16/2021
Veterinary reviewed by Michele K.
Why is my dog lethargic?

What is Lethargy?

Lethargy is a general weakness or tiredness in your dog that may occur.  It may be a short term problem, or can be one of the first signs of a serious condition such as hypoglycemia, cancer or diabetes. If your dog is laying around, does not want to play, and is generally unhappy for longer than 24 hours, you should call your veterinarian. Some of the reasons for lethargy in dogs includes:

  • Depression
  • Old age
  • Medical conditions

You should also watch for loss of appetite, weight loss, increased body temperature, breathing difficulty, and digestive issues such as vomiting and diarrhea. If you notice any of these symptoms, you should see a medical professional as soon as possible.

Why Lethargy Occurs in Dogs

Lethargy can occur for many different reasons, some that are mild and do not need treatment and others that may be life-threatening. Some of these include:


Your dog may be depressed due to the loss of a playmate or family member. Some dogs can actually get clinical depression caused by an imbalance of certain chemicals in the brain. Although it is still unknown why this occurs in some dogs, veterinary professionals believe it may be hereditary as it is in humans.

Old Age

As a dog ages, their energy level drops and they may develop painful conditions like arthritis that makes them want to lay around. If  you see any of these signs, you should call your veterinarian.

Medical Conditions

There are many illnesses that can cause lethargy, but the most common ones are:

  • Anemia is a decrease in red blood cells and iron in the blood
  • Distemper is a serious virus that causes a high fever, respiratory distress, nasal discharge, anorexia, gastrointestinal distress, and neurological disorders (paralysis and seizures)
  • Parvovirus is a serious and often fatal condition that causes extreme vomiting, diarrhea, and anorexia
  • Diabetes is a sugar regulating disease that causes increased urination, excessive thirst, sleepiness, and depression
  • Hypothyroidism is caused by thyroid hormone deficiency
  • Dehydration is a dangerous lack of water and electrolytes such as potassium, chloride, and sodium
  • Heart disease such as cardiomyopathy, congestive heart failure, and heartworms can all cause lethargy
  • Liver disorders such as hepatitis, bile duct obstruction, or liver disease cause lethargy as well as jaundice, appetite loss, diarrhea, and vomiting
  • Kidney disease can make your dog lethargic and he may also be urinating more than usual and have fluid retention
  • Nutritional deficiencies cause lethargy and may be caused by an underlying illness
  • Respiratory distress from infection or any other cause will make your dog lethargic
  • Cancer of any kind can affect your dog’s energy levels and cause many other various symptoms depending on where the cancer originates
  • Osteoarthritis is a painful condition that creates lethargy and depression as well as swollen joints

What to do if your Dog is Lethargy

If your dog is depressed, you can try spending more time with him. Take him for walks and play a favorite game such as fetch. Exercise is a good way to increase the endorphins in your dog’s brain, which can help alleviate depression. However, if it continues for longer than a few days, you should call your veterinarian because it can be a sign of an underlying illness. Old age cannot be cured, of course, but you can make your dog more comfortable with medication from your veterinarian. The veterinarian will give your dog a complete physical examination to determine if he has arthritis or other painful conditions that may be helped with medications or physical therapy. Because of all the other medical conditions that cause lethargy in dogs, you should take your dog to see your veterinary care provider if he continues to be lethargic for longer than 24 hours.

Prevention of Lethargy

Depression cannot be prevented, but it can be treated with medication. Provide plenty of attention and exercise for your dog and feed him a high-quality dog food specially made for his breed and age. The veterinarian can help you find the right food for your dog. Old age is not something that can be avoided either, but you can make your dog’s quality of life much better with preventive veterinary care while providing the appropriate of diet and exercise. Some medical conditions may be prevented with regular visits to the veterinarian, but some are not escapable and just have to be treated when they are diagnosed. Parvovirus, distemper, and heartworms can all be kept in check with regular vaccinations.

Cost of Lethargy

The cost of treating lethargy can range quite a bit. Depression can end up costing you about $200 for a veterinary visit and tests, with a monthly cost of about $20 to $50 for medications, if needed. The price for making your dog comfortable as he ages may run you about $150 to $400 for an office visit and tests with monthly medication costs that will vary with treatment. The costs of treating medical conditions that cause lethargy range from about $300 - $600 for fluids and electrolytes to treat dehydration, up to $10,000 for a more serious illness like heart or liver failure.

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Lethargy Questions and Advice from Veterinary Professionals


German Shepherd




7 Years 2 Months


0 found this helpful


0 found this helpful

My pet has the following symptoms:
Increased Thirst
she's not very lethargic but she has periodically what sounds like hiccups (your system wouldn't let me put that in)

July 26, 2017

0 Recommendations

Like humans, dogs may also get hiccups which is caused by spasms of the diaphragm which may be caused by swallowing of air (distending the stomach), diet and other causes (which are less likely). If you notice the hiccups are getting more frequent or you notice symptoms of loss of appetite, abdominal pain, abnormal breathing or anything else concerning you should visit your Veterinarian otherwise discuss it with them during your next annual visit. Regards Dr Callum Turner DVM

July 26, 2017

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german shepard




1 Year


0 found this helpful


0 found this helpful

My pet has the following symptoms:
Super Mellow,Cautious, Loss Of Acti
Within the last two days my dog has gone from hyper, friendly And energetic to mellow, cautious, loss of appetite, minimal physical activity. When we go out in our back yard she will trot over and grab her ball and bring it over but then lay down. When we sit close to her and talk to her and pet her, she puts her ears back. What is wrong with our little girl?

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