Why Is My Puppy Lethargic

Why Is My Puppy Lethargic?

Signs and symptoms Why is my puppy Lethargic can appear with many Health and Wellness issues in Puppies, especially if your pup is acting tired. The only way to determine the cause is to get treatment from a veterinarian to examine the puppy. Continue reading to understand more about weak puppies and how you can detect the possible sources of lethargy in puppies and get immediate attention when necessary.

Lethargy in Puppies?

Signs of Weakness in a puppy is a lack of energy. So, what does that mean for your young puppy? It’s crucial to distinguish if your puppy is genuinely lethargic (which could indicate a medical issue) or if he is just tired.

It may be challenging to make that distinction, but you know your dog better than anyone. Recognizing when your dog is lazy and being proactive helps your veterinarian give your dog the best care.

Differences Between a Lethargic Dog and a Tired Dog?

A lethargic puppy is unusually inactive and not interested in getting up. The severity of lethargy can vary from moving slowly to having no interest in walking or playing.

Tired puppies may feel sleepy but are easily roused and ready to pop up if they hear the treat jar or the leash jingle.

What is Normal when a puppy is Lethargic?

If you have taken a long walk or had a lot of exercises (especially in the heat), your puppy may sleep for hours afterward. If your puppy has been at daycare or a boarding kennel, they may be excited and on alert and then come home and sleep.

Suppose there was no activity or exertion; would that cause your puppy to sleep more or be more tired than usual? 

In that case, it might be a case of lethargy, and the puppy will need to see a veterinarian immediately.

When born, puppies need more sleep and spend most of their time eating and sleeping. However, puppies are very easy to wake up; if it is difficult to wake up a puppy, they will need to see a vet immediately. They may not hear well, so they might not wake up as fast when you come in. Once they do, the puppy should be awake and ready to play as long they are not lethargic.

What Causes Dogs to be Lethargic?

The causes of lethargy in dogs can be different for every dog. The most common causes of inactivity are Infections, including parvovirus, distemper, kennel cough and leptospirosis. There are also diseases like heart, liver, diabetes, and hypoglycemia. Medications include newly prescribed drugs or a new flea or worm product.

Dogs of All Ages

Dogs of any age can become sluggish with any sickness, such as an infection or injury. Low thyroid levels can cause lethargy in dogs.

Making sure your dog is not feeling well early on and getting treated by veterinarians before symptoms worsen can make a difference in his well-being. Early detection is vital to help your dog get his strength back quickly.


Puppies, when young, can suffer from hypoglycemia (low blood sugar), which can cause incredible weakness. It is the most common issue in tiny puppies and pups less than four months of age. Their tiny livers don’t have the strength to help increase blood sugar, especially if the puppy is not eating and feeling energetic.

When moving to a new home, puppies don’t eat well when adjusting to their new home or have eaten something they shouldn’t have, which would cause their appetite to decline.

In Senior Dogs

Older dogs are sometimes affected by arthritis and other joint conditions that cause pain and inflammation. Dogs tend to hide their pain, so if your dog is not eager to get up and do what they usually do, you should talk to your veterinarian to get them some help.

Older dogs are also more prone to internal organ problems, such as tumors or heart problems which cause a real lack of energy; this may be the first symptom you see before calling a veterinarian to investigate the issues.

How soon should a Vet be called if you suspect your dog is Lethargic?

You must call a veterinarian if you are worried about your dog’s health as he is feeling weak and not acting like he usually does. Get him checked by your veterinarian immediately.

Symptoms to look out for which are signs of an emergency:

Pale gum colour can indicate the dog has internal bleeding that can lead to a life-threatening issue)

Abdominal that looks Distended (can be a sign of bloat or other abdominal problems, like blockage)

Labored breathing or blue or purple tongue colour (often due to heart or lung problems that need urgent medical attention)


If your dog is weak and trembling, it is commonly a sign that they are in pain. It may not be noticeable where the pain may be, but it’s a sign that your dog is in pain and needs immediate care by a Vet. Sometimes a dog is unsure of his feelings and moves as little as possible, so they don’t hurt themselves.

There could also be spinal pain caused by an inflamed disc or another neurological issue. Soft tissue injuries or gastrointestinal problems can often cause the dog to be weak. 

Not Eating

Feeling no hunger in puppies is also a symptom of hyperglycemia, but not eating, combined with lethargy, means that the dog needs medical attention and should not be ignored for more than 24 hours.

Labored Breathing

It is often a severe symptom that needs to be recognized early. There is a difference between panting and labored breathing. With breathing, you will see your dog moving belly muscles up and down rapidly and with force.

Shallow breathing can be caused by several conditions that need to be treated as soon as possible by a veterinarian:

Heart failure


Fluid in the lungs or abdomen

Laryngeal paralysis (a serious problem with the larynx)

Severe pain

Airway blockages

Drooling or Vomiting

If your dog is weak and drooling, it could mean they are nauseous or have ingested a toxic substance. It’s essential to check the environment to see if it could have eaten contaminated food found on the ground. If your dog is Drooling, it can induce vomiting, which can be many issues.

Upset Stomach

Dogs may have an upset stomach if they eat rich foods (which can lead to severe pancreatitis) or swallow a stuck object. If a dog is so afraid that they are acting listless and uncomfortable, the puppy must be seen by a veterinarian immediately.

How Do Vets Treat Lethargy in Dogs?

When the dog arrives at the Vet office, he will first do a physical exam and check your dog’s gum colour, if the dog is hydrated, check vital signs with the heart and lungs, and do abdominal palpation to check if it is palatable, and also check the spine and joints.

Diagnostic Imaging

They will next recommend diagnostic testings by starting bloodwork and followed by x-rays. These tests will help the Vet thoroughly by checking all body organs to determine if there are serious issues. 

The tests’ benefits rule out certain diseases or problems, which is crucial information to help find the issues. Like human physicians, veterinarians cannot always find an answer for every patient. 

Still, vets know what to look for as they have studied the profession.

Veterinarians will offer specific treatments such as pain control, fluids if a dog is dehydrated, antibiotics for infections,anti-nausea drugs if your dog is vomiting and Probiotics to help stomach enzymes. 

Your severely ill dog must get treatment early before the issue becomes an emergency.