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My Dog is Lethargic but Eating and Drinking: 14 Reasons

Many people have been there.

Your dog seems to be under the weather and not himself.

But when does it actually border on lethargy and what could your dog suffer from?

If your dog is lethargic but still eating and drinking, that’s a very non-specific symptom and could point towards a host of issues, all of which need to be taken care of.

For some cases of lethargic dogs, there are definitely home remedies while others require a vet visit, let’s shed a bit of light on this topic.

My Dog is Lethargic but Eating and Drinking

If your dog is lethargic but eating and drinking, common causes include overexercise, boredom, fear, poisoning, inflammation, or medication, as well as mental or chronic disorders.

The fact that your dog is lethargic but still eats and drinks is a good sign since that’ll avoid an emergency vet visit for nutrient deficiency.

However, some cases still need to be treated pretty quickly while others just depend on easily changeable external factors (such as exercise).

Also, the circumstances and other symptoms can be crucial.

Here are some signs that point towards certain causes (it’s not an exact science though and a vet visit might still be required to rule out other issues).

  • Have you recently changed the exercise regimen? Overexercise or boredom come to mind.
  • Recent rescue or traumatic event? Fear is common.
  • Right after a walk or after devouring bad food? Check for poisoning
  • Visible injury? Could inficate infection or inflammation
  • Recently put on meds? That might the cause
Person drips water into their hand from a bottle and small dog drinks it.

Also, is your dog suffering from any of these symptoms as well?


Although the opposite is more common, it might just be that you ramped up your pooch’s exercise regime too quickly.

If you’ve gone on an extremely long hike or just introduced a new activity such as biking or swimming, your dog might just be tired from that.

While this kind of acute overexercise is possible, it’s also possible that the exercise regimen has been too much for your dog to keep up with for weeks or months already.

If nothing has changed and you’re reasonably exercising your dog (which is essential), this is one of the unlikely causes of your dog’s lethargy.


If your dog is lethargic but still eating and drinking, it might very well be that your dog is bored out of his mind, perhaps eventually leading to depression or behavioral issues.

Some dog owners assume it’s just certain breeds that need mental and physical exercise but that’s plain wrong.

What’s true is that some breeds have higher exercise needs but all need to be kept busy to avoid boredom which can resemble lethargy.

Boredom can also lead to hyperactivity inside the house or overexcitement outside but both extremes are undesirable and should be looked into.

Fear or Trauma

Loud noises, negative experiences, unfamiliar surfaces, even a new environment can make some dogs fearful, especially if you’ve recently rescued a dog.

You’ll be the best judge of what might’ve led to that lethargy in your dog.

If your dog started to seem lethargic but is still eating and drinking recently, you should try to recall the day it started to figure it out.

Brindle-colored dog lying with the head on the floor stares into the camera, looking lethargic or sad.

It might only be a matter of time for your dog to stop drinking or eating altogether if the lethargy isn’t addressed.

Check this to see how you can build confidence in your dog and how to handle a rescue dog’s fear if you’ve recently brought one home.


Food poisoning is more common than you might think, considering there are a lot of foods your dog shouldn’t dig into since they’re toxic.

Your dog could also just feel a bit down because he stuffed his face with that yummy dinner where the spices alone suffice to upset a dog’s stomach to the point where they seem to be lethargic and sick but still drink, perhaps even more so to compensate.

If your dog picked something up while walking outside and doesn’t seem like himself anymore, keep poisoning in mind and consult a vet asap.

Infection or Inflammation

Inflammation can be caused by an infection which in turn could be the result of an injury.

You don’t see any visible injuries? Then your vet might order bloodwork to be done.

This is often paired with a fever and can definitely be the cause why your dog is acting lethargic.


Your dog was put on medication recently and now he’s lethargic but still eats and drinks? That switch could be the cause.

Consult your vet to see if this behavior change is a known side effect and if the meds aren’t crucial at the moment, you can try banning them from your dog’s daily to-do list and see if he improves and becomes more active again.

Old Age, Disorientation, Depression

Dogs who just get older become calmer and calmer and if they’re lethargic but still drink and eat normally, everything might be okay with your dog’s health charts.

Disorientation, restlessnes, or paranoia are serious symptoms and should be addressed.

If your senior dog is not only lethargic but stares at random points inside the house, is disoriented and circles a lot, and so on you might look into canine dementia.

Diabetes, Heart Disease, Immune System Disorders, Cancer

The more serious causes for your dog’s lethargy include diabetes, heart disease, immune system disorders and cancer.

While you may already know aboout your dog’s diabetes or immune disorders, there might be uncovered health issues and only the vet can help you determine if your dog might suffer from any of these conditions.

While there’s no reason to be on high alert just because your dog seems to not feel well for a day, you should definitely look into it if your dog behaves the same for the next day without any apparent reason.

My Dog is Lethargic and Not Himself

If your dog is lethargic and not himself, you should look into common causes such as exercise issues, fear, poisoning, nutritional deficiency, or neurological disorders.

Neurological reasons are quite common causes for your dog not feeling like himself.

These causes mostly affect senior dogs (hence why canine dementia plays a big role) but dogs of all breeds and ages can be affected too.

Behaviors that point towards neurological disorders include a lot of circling behavior or paranoid behavior where your dog also seems to see things inside the house.

My Dog Seems Sad and Tired

Dogs who seem sad and tired can suffer from depression, neurological disorders, or just boredom or old age.

Everybody has bad days and good days but if your dog acts lethargic or overly sad, you should ask your vet.

In mild cases, it’s just boredom or your dog might havr slight separation anxiety if one of his favorite people or dogs just left.

While dogs tend to get calmer with old age, it’s not common that they suddenly turn all sad and tired.

In general, you’re the best judge of your dog’s behavior and it’s important to put things into perspective.

Mellow dogs have a totally different starting point compared to an active, excited canine making a one-eighty turn to becoming sad, tired, or even lethargic.

If your dog suffers from a diagnosed condition already, this might be a particularly bad day for him.

When Should I Be Concerned About My Dog Being Lethargic?

You should be concerned about your dog being lethargic if he doesn’t react to stimuli and behaves weirdly for 24 hours or more while you should monitor the situation even more closely if he quits drinking and eating.

If you’re unsure, go the safe route and ask your vet.

Monitor your dog’s behavior closely, make sure they’re drinking and eating and get some exercise in and try to engage them but avoid disturbing when they’re resting.

About Danielle

I am the founder of PawLeaks where I share weekly tips on dog training and behavior. Sharing a passion for dogs and helping owners to solve problems through understanding canine behavior and modification is my number one goal.