As dog owners, we’re used to our furry friends energetically greeting us when we walk through the door; getting excited any time we mention going for a walk or car ride; and buzzing around like little bees when they’re bored and restless…
But what if your dog stops behaving this way for no apparent reason? What if one day, out of the blue, they just don’t seem interested in moving around or doing anything?
If your pup suddenly seems lethargic, they may just be tired from normal play and exercise, or they may have an underlying condition that is sapping their energy. There are several ways to determine if your dog’s lack of energy is normal or a symptom of something more serious. Keep reading to learn more…

Why Your Dog Has Lost Their Energy
Before assuming that your dog is sick, try to recall what they’ve been up to for the past two or three days prior. If they’ve recently had a whole day of playing, they may just be tired. Let them rest for a day or two, and see if their energy levels return back to normal.
Puppies, in particular, can run out of steam fast. They may sleep for 15 hours or more in a single day before they have fully recharged their batteries. Similarly, senior dogs also tire out quickly, and need long recovery periods before they’re ready to play again.
If your dog’s lethargy appears to have nothing to do with normal play and exercise, there’s a good chance they might be sick or even depressed.
For example, ticks and other parasites can drain a dog’s energy, making them lethargic and listless. Heart disease can also cause a dog to lose their energy.
On the other hand, your dog might not have a physical illness but they may be depressed. Just like people, dogs can become sad for a wide variety of reasons, and when this happens, they lose their excitement for life.
In previous articles, I’ve discussed in depth how to tell if your dog is sick or depressed. If you think your dog might be sick, click here to find out the top signs indicating they need to see a vet. If you think your dog might have depression, click here to learn about the symptoms and treatment.
Some Breeds Just Have Less Energy than Others
In some cases, your dog’s lack of energy might not have anything to do with them being exhausted, sick, or depressed. The fact of the matter is, some breeds are just lazy by nature.
For example, Mastiffs have a reputation for being lazy. Their large bodies use up a lot of energy quickly, so they prefer loafing around instead of being active. They’re basically the couch potatoes of the dog world.
Other breeds known to be lazy, include, but are not limited to: Bulldogs, Basset Hounds, and Saint Bernards.
Before you assume the worst, I’d recommend finding out if laziness is characteristic of your dog’s breed.
References:
Cummings School of Veterinary Medicine. Reduced Ability to Exercise (Exercise Intolerance). Retrieved from https://heartsmart.vet.tufts.edu/reduced-ability-to-exercise-exercise-intolerance/