Is your dog tired, lazy, or lethargic? These terms could describe your dog after an activity or on a hot summer's day. But when your pet is sluggish day in and day out, then it's a red flag.

You know your dog best, and when anything about their behavior is out of the ordinary, you need to monitor the change. While it's normal for your furry family member to pass out for most of the day, a drop in energy levels and enthusiasm during their waking hours can indicate that something else is making Fido flat. 

Are you trying to find the reasons behind your dog's lifelessness? Read on to learn about the common causes of lethargy and how you can help your pooch. Spotting symptoms of serious illness are best done early on in a diagnosis. Don't delay a visit to the vet if you're worried about your pup.

What Is Lethargy In Dogs?

Grab that leash or prep dinner, and dogs usually come running. If sad, tired eyes have replaced their typical joyous reaction, it's time to get down to their level and figure out the problem. Lethargy is easy to identify. Your dog may display it in the following ways:

  • Lack of interest in ordinarily exciting activities: mealtime, their favorite toy, or the shake of a leash

  • Exhaustion, dopiness

  • Staggered, slow movements

  • Low vitality

  • Little or zero reaction to sensory stimulation

  • Exercise intolerance

  • General apathy for something that would usually pique their curiosity

Lethargy is often on that dreaded list of symptoms that typify a disease. So when the potential cause for sedentary behavior is so vast, how do you pinpoint the problem? A wise approach would be to list accompanying symptoms so that you can phone or email your veterinarian with comprehensive information. 

Any slow progression of a symptom is a sign of a disease that is becoming increasingly more severe. Mild apathy that slowly becomes a complete disinterest in all things great, requires immediate medical attention. While dog lethargy can indicate several problems, here are the most common health problems in dogs where sluggishness is a case for concern. 


The following infectious diseases are common in dogs and include lethargy as a symptom:

  • Kennel Cough is a highly contagious respiratory disease that induces bronchial and trachea inflammation. Other signs include coughing, retching, a snotty nose, lack of appetite, and fever.

  • Leptospirosis, caused by bacteria, is found in urine, contaminated water (rivers, streams, ponds), and soil. Vomiting, diarrhea, and disinterest in food are common signs that the leptospira bacteria has infected your puppy.

  • Parvovirus is a dangerous and contagious virus spread through feces and cross-contamination. It strikes the immune system, cardiovascular system, and gastrointestinal tract. Signs of Parvovirus include fever, diarrhea, dehydration, weakness, dark or discolored gums, and increased heart rate.

  • Distemper is a severe and sometimes fatal viral disease that affects the nervous system, gastrointestinal tract, and respiratory system in dogs and many other pets. It's spread through cross-contamination and respiratory droplets. Symptoms include cold-like traits, depression, coughing, vomiting, loss of appetite, pneumonia. 

  • Parasitic, fungal, or flea infestations are common in animals and can cause anemia due to blood loss, causing lethargy. Heartworm is a parasitic worm infection that resides in a dog's pulmonary arteries.


A good drink of water might be all your doggo needs. During a busy day, you may forget to top up your dog's water bowl. Make sure your dog has access to fresh water inside and outside. If your dog seems lethargic in a heatwave or after a good exercise session, giving them new, cold water might be all they need to perk them up again. 

Poor Diet

Eating poorly will affect your energy levels, and it's the same for your dog. Your dog needs a range of nutrients in its meal to have the stamina for everyday activities. Good dog food = fuel for the day. Amino acids from proteins, carbohydrates, vitamins, fatty acids, minerals, and water are necessary to survive.

Select a food brand that is free of non-nutritious additives. Dogs have varying energy needs in different life stages. Please speak to your vet about your dog's best diet choices, given their age and specific needs. 

Old Age

Is your old dog slowing down? While this may seem par for the course, the reasons for their lethargy may be more serious. Senior dogs are prone to arthritis, a progressive disease that is characterized by inflammation of the joints. In response to the pain caused by inflammation, dogs with osteoarthritis slow down, avoid normal movement, and become lethargic. 


It's only natural to slow down if you're in pain. Dogs who are experiencing discomfort and soreness may become lethargic and miserable. Look out for accompanying signs of distress such as gnawing, reduced mobility, compulsive licking, lack of appetite, or inflammation. Pain could be caused by an internal trigger or can be from a more visible trauma. 


An obese dog is in danger of developing metabolic complications that affect the cardiac structure, resulting in heart problems. Other metabolic issues can cause diabetes, insulin resistance, hypoglycemia, hypertension, and liver problems. Obesity is preventable, and it's not too late to help your dog get back on track to a healthy weight.

Obesity has many causes, mostly in your control: overeating, exercise intolerance, lifestyle changes, and more. If your dog is picking up the pounds, make an effort to identify the problem, and start a treatment plan. 


There are so many toxins and human foods that dogs should not eat. This doesn't stop them from trying to consume anything and everything. From stinky diapers to your full blister pack of prescription medication, some canines have no limits to the objects they'd eat.

The list of items that will cause toxicity in your pet is long. The most common toxicity signs are gastrointestinal upset, blood in vomit or stool, loss of appetite, lethargy, decreased respiratory rate, agitation, tremors, and seizures.

Adjustment to New Medications

Reactions to new medications are unpredictable. When introducing drugs to your pet, whether prescription medication or a new flea product, monitor them closely for any issues. Avoid giving your dog human medications, and instead, call or email your vet before giving anything new to your precious pooch. 


Yes, your dog can feel all the emotions and experience a dip in its mental health. Lethargy in dogs, antisocial behavior, and exercise intolerance are typical behavior patterns of a pet down in the dumps. Depression in your dog will manifest if there has been a dramatic change in circumstances, a move, loss of a loved one, an addition to the family, or even separation anxiety. 

Treatment For Dog Lethargy

First off, give your dog a bit of nourishment and fresh water. Allow your dog to rest and provide quiet by removing them from any pestering doggy siblings. A busy day or a slight upset stomach may just put them out of joint for a few hours, and with time to rest, they'll hopefully be back to their usual selves. 

Monitor any changes in their demeanor and list other symptoms. If lethargy, or a refusal to eat and drink continues for more than 24 hours, call your vet for advice and book an appointment. 

Go through the following questions to give yourself a better idea of why your dog may be lethargic. 

  • Does your dog have an average heart rate? A strong heart rhythm for dogs is between 70-120 beats per minute. 

  • Do they have a fever? The average body temperature for canines is 101 - 102.5 degrees Fahrenheit (38.3 - 39.2 degrees Celsius). 

  • What are their gums telling you? Discolored gums or a stinky breath can be a sign of bad health or even gum disease. If your pet has a dental condition, they may not be eating their food, and as a result, they'll be experiencing lethargy.  

  • Are their eyes bright, white, and moist? Eyes that are bloodshot, cloudy, or display asymmetrical pupil sizes indicate undesirable conditions. 

  • Is there a physical reason for concern? Do you see any blood, lacerations, infections, injury, swelling? Give your pet a full once over, placing pressure on their body to assess whether they are in pain.

  • What's happened in the past 24 hours? Has your pet had a strenuous day? A playdate may have exhausted them, and your dog may simply be tired. 

  • Did they have access to any poisons? Call the Pet Poison Helpline or your vet to be advised on the best response if you suspect an ingested toxin.

CBD for Lethargic Dogs

If you're looking for a holistic option to help your dog with discomfort or stress, you may want to consider CBD as well.

More and more pet parents are seeing firsthand how CBD can help support healthy hip and joint health, help with occasional discomfort, promote relaxation, support the immune system, and more! 

CBD works by interacting with a dog’s internal endocannabinoid system, helping to support normal cardiovascular, occasional discomfort, and neurological function. CBD can also support and dog's immune system and help maintain physical and mental well-being to get your pup's pep back in his step.

Don't just take our word for it though – take a look at all the success stories of pet parents who've used CBD for these reasons and more.

When To Visit The Vet

No matter their age, a lethargic dog is not a good sign. Once you've realized that your dog's condition isn't improving, call your vet for an urgent appointment. Your vet will perform a full examination and possibly some diagnostic tests to rule out the possible explanations of lethargy. Follow your vet's treatment plan and diet recommendations. 

Disease Prevention

Disease prevention is possible with vaccinations. Puppies are incredibly vulnerable to fatal, contagious illnesses. The knowledge that your pup has had their shots will give you peace of mind.

Deworming your animal, controlling flea infestations, and annual wellness exams will keep your pet in good health. Adopters should make it a priority to check vaccination cards and confirm that the necessary shots took place.

Lethargic Dog? Our Final Thoughts 

Causes for lethargy are vast and trying to find the cause may seem like that dreaded dive into a rabbit hole of google searches. It's essential to keep your dog at peak fitness to limit the possible issues. Annual checkups are important for any stage of your dog's life. If you have questions, find a vet that you're comfortable talking to and partner with them to keep your doggo happy, healthy, and full of life for the rest of their days. 

 You have the chance to make your lethargic dog feel good again.

Frequently Asked Questions

Why is my old dog lethargic?

Senior dogs are prone to arthritis, a progressive disease that is characterized by inflammation of the joints. In response to the pain caused by inflammation, dogs with osteoarthritis slow down, avoid normal movement, and become lethargic.

What causes a dog to be lethargic?

Several things can cause lethargy in animals. Contagious infections like kennel cough, leptospirosis, parvovirus, and distemper all include lethargy in their symptoms. Toxicity, poor diet, pain, obesity, metabolic illnesses, heart disease, and dehydration are also possible problems. Look out for other symptoms to pinpoint the cause. 

Why is my dog lethargic and not eating?

Discolored gums or a stinky breath can be a sign of bad health or even gum disease. If your pet has a dental condition, they may not be eating their food, and as a result, they'll be experiencing low energy and lethargy.  

Is my dog depressed?

Inactivity in dogs, exercise intolerance, and general disinterest in their usual joy-giving activities are typical behavior patterns of a pet experiencing depression. Depression in your dog will manifest if there has been a dramatic change in circumstances, a move, loss of a loved one, an addition to the family, or even separation anxiety.