What Is Lethargy in Dogs?

A lethargic dog is out of energy and lacks enthusiasm for his usual favorite things.


Lethargy in dogs is more than being sleepy after a long hike. That’s being tired. A lethargic dog is sluggish, sometimes not even wanting to get up to eat. A lethargic dog usually doesn’t feel well.

Lethargy in dogs may be a passing thing, like he just doesn’t feel well on that day for some minor reason, or it could be sign of underlying health problems.

Causes for Lethargy in Dogs

Causes for lethargy are many. It might be as simple as a hot, humid day that makes your Malamute want to lay around an AC vent or blowing fan and dream of snow drifts. This dog isn’t really sick, but he understandably isn’t feeling energetic either. More concerning is when your young dog is lethargic without an environmental reason.

Fever: A common cause of lethargy is a fever. Just like you when you have a fever, your dog is exhausted, grumpy, and just wants to be left alone. Take your dog’s body temperature. It’s pretty easy with modern digital devices. Normal body temperature for dogs is 101 to 102.5°F (38.3 to 39.2°C). Know your dog’s normal by taking his temperature periodically when he feels well. Some dogs naturally run a tad under or over.

Pain: Another common cause is pain. A dog in pain does not want to get up and go play fetch, although fanatic retrievers sometimes do so even in great pain. It is your responsibility as an owner to recognize pain and not push your dog. Pain could come from an injured leg or a crampy stomach. Do a gentle physical exam and note any signs of pain, which might be a subtle catch in his breath when you touch the area.

Illness: Lethargy can also reflect various illnesses. Anything that causes anemia may slow your dog down. Cardiac or respiratory problems also mean less oxygen to the tissues so less energy. A tickborne disease could be the culprit. Even scented candles can cause lethargy. Metabolic problems like liver or kidney disease can simply make a dog feel lethargic, ill, and not like playing.

What You Can Do

If your normally energetic pooch is lethargic for one day and has no other clinical signs, it may be OK to just observe him. Two days of lethargy, however, should be a cause for a veterinary visit even if you don’t notice anything else off. Remember, dogs are good at hiding physical problems.

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Deb M. Eldredge, DVM, is a graduate of Cornell University’s College of Veterinary Medicine and the first recipient of the vet school’s coveted Gentle Doctor Award. Currently retired from clinics, Dr. Eldredge is an award-winning writer and the technical editor of Cornell’s DogWatch. She and her daughter own the Coyote Run Belgian Tervuren kennel. Dr. Eldredge actively competes her dogs in all dog sports and breed shows.