Why Is My Puppy Lethargic

Why Is My Puppy Lethargic?

Signs and symptom that can appear with several health and wellness problems in Puppies. If your pup is acting tired, the only way to absolutely determine the cause as well as the best treatment is having a veterinarian  examine them.  Continue reading to understand more about sluggish puppies, from just how to inform sleepiness, exhaustion and possible sources of lethargy in pups, and when to call the vet.

Lethargy in Puppies?

Lethargy is defined as a lack of energy and enthusiasm, but what does that mean for your puppy? It is an important distinction to know if your puppy is truly lethargic (which could indicate a medical issue) or is just tired.

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

Difference Between a Lethargic Dog and a Tired Dog?

A puppy that is lethargic is unusually inactive and not interested in getting up and doing normal activities. The severity of lethargy can vary but ranges from just moving more slowly to really having no interest in walks or play.

A tired puppies may just be sleeping but is easily roused and ready to pop up if they hear the treat jar or the jingle of the leash.

Is It Normal for a puppy to be Lethargic?

If you have a good explanation for your puppy to be tired, then that may be the case.

If you have taken a very long walk or had a large amount of exercise (especially in the heat), then your puppy may sleep for hours afterward. If your puppy has been at day care or a boarding kennel, they may be really excited and on alert most of the time there and then come home and just crash.

If there is no unusual activity or exertion that would cause your puppy to sleep more or be acting more tired than usual, then you may be dealing with lethargy and your puppy may need veterinary attention.

Just like humans, puppies need more sleep when they are very young . Young puppies are like babies and spend most of their time eating and sleeping. However, puppies are also relatively easy to rouse, and a difficult-to-wake puppy may mean something else is going on. For example, if you have difficulty waking your puppy, you may be dealing with a case of low blood sugar.

Senior dogs also need more time napping and get tired more easily after walks and playing. They also may not hear as well, so they might not wake up as easily when you come in. Once they are roused, though, they should be awake and ready to engage if they are truly just tired and not lethargic.

Causes why Dogs would be Lethargic?

Causes of lethargy in dogs can vary by age. Here are some of the most probable causes of lethargy in dogs at each life stage.

Dogs of All Ages

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

Recognizing that your dog is lethargic early on and getting your dog treated by the vet before their symptoms get worse can really make a difference. This can help your dog get back to normal as soon as possible.


Young puppies can suffer from hypoglycemia (low blood sugar), which can cause profound lethargy. This is most common in pups less than 4 months of age and in toy breeds. Their livers do not have the reserves to increase blood sugar, especially if they aren’t eating well.

Sometimes they don’t eat well if they are adjusting to their new home or if they have eaten something that they shouldn’t, which throws off their normal appetite.

Senior Dogs

Senior dogs are more often affected by arthritis and other joint conditions that cause pain. Dogs tend to hide their pain until they can’t take it any longer, so if your dog is not eager to get up and do the things they normally do, you should really pay attention to this and get them some help.

Seniors are also more prone to having internal problems with their organs, such as tumors or heart problems. This causes a real lack of energy that may be the first symptom you see.

When Should You Call a Vet About Lethargy in Your Dog?

If you are concerned that your dog is truly lethargic and not acting like they usually do, it is never the wrong thing to call your vet to get them checked out sooner rather than later.

Take your dog to the veterinarian immediately if they are lethargic and have any of the following symptoms, which are signs of an emergency:

Pale gum color (can indicate internal bleeding and can lead to life-threatening anemia)
Distended abdomen (can be a sign of bloat or other abdominal emergencies)
Labored breathing or blue or purple tongue color (often due to heart or lung problems that need urgent medical attention)

Dogs With Other Symptoms

If your dog is lethargic, they may also have other symptoms. Here are some common symptoms you might see alongside lethargy and what these combinations mean.


If your dog is lethargic and shaking, it is most commonly a sign of pain. You may not know where the pain is, but it’s a sign that your dog is in distress and is not feeling well. Sometimes the dog isn’t sure what is going on either and is trying to move as little as possible so they don’t hurt as much.

It could be spinal pain caused by an inflamed disc or another neurologic issue. Soft tissue injury or gastrointestinal pain often cause lethargy and shaking as well. These symptoms can also be signs of a fever.

Not Eating

This is also a nonspecific symptom, but not eating combined with lethargy means that the dog is bothered so much by their medical issue that they don’t want to eat and don’t have energy to be themselves. This should not be ignored for more than 24 hours.

Labored Breathing

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

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

Heart failure


Fluid in the lungs or abdomen

Laryngeal paralysis (serious problem with the larynx)

Severe pain

Airway blockages

Drooling or Vomiting

If your dog is lethargic and drooling, it could mean they are nauseous or have ingested a toxin. It is important to check their environment to see if there is anything they could have gotten into. Drooling can progress to vomiting, which can have many causes.

Dogs can have an upset stomach if they eat something too rich for them (which can lead to serious pancreatitis) or swallow an object that gets stuck. If a dog is so nauseous that they are acting listless and uncomfortable, they definitely need to be seen by a veterinarian.

How Do Vets Treat Lethargic Dogs?

Your veterinarian will first perform a physical exam and check your dog’s gum color, hydration status, vitals with the heart and lungs, abdominal palpation, and spine and joint palpation.

Once they find where the problem may be coming from, they will recommend diagnostic tests, usually starting with bloodwork and x-rays. These tests will help the vet do a thorough check of all body systems and determine if there is something serious going on with your dog’s internal organs.

Sometimes the benefit of the tests is to rule out certain diseases or problems, and this is very valuable information. Just like human physicians, veterinarians cannot always determine an answer for every patient, but they know what to look for and how to make your dog as comfortable as possible.

They will offer specific treatments such as pain medicine, fluids if your dog is dehydrated, antibiotics if there’s an infection, or anti-nausea medicine if your dog is vomiting. It is always in your dog’s best interest to seek treatment early and not wait until they are severely ill and it becomes an emergency situation.

labradoodle-puppy for sale

Puppies Growth

Everyone loves cute puppies – young and old alike. Puppies are cute and totally adorable, exactly the same words we use when describing babies! Puppies are incredibly similar to babies!

  • They are part of our family
  • We agonize over the names we give to our puppies
  • A puppies health is of prime concern and just as with babies we ensure that they are vaccinated against disease
  • Puppies whine when they are hungry, thirsty, hot, cold, uncomfortable, distressed or lonely
  • They require considerable attention
  • We feed them special food for puppies
  • We provide them with toys for puppies
  • We ensure they have their own bed, and their own space within the home
  • We have to teach them acceptable behavior and social skills
  • We even teach puppies our language!
  • And as they get older we often send them to puppy schools!
  • We worry about them if they become sick
  • Puppies in their turn look on as as their surrogate mother, litter companions and the leader of their pack (or family)

Once we understand the role of puppies within our family their particular requirements become incredibly clear – as does the role we are expected to play in their lives!

When will my puppy stop growing?

Physical maturity is reached at different ages, depending largely on the size of your dog. Little dogs stop growing much sooner than big dogs.

The chart below will give you an idea of what I mean. The squares that are left blank indicate that the dog has stopped growing by that point.


The chart above will also give you an idea of what you might expect your puppy to weigh at different stages in his development.

Again, this is closely linked to the size of the breed he belongs to.

But if this is just a rough guide, how will you know for sure if your puppy is underweight or overweight, or just right?

And what exactly do I mean by Toy, Small, Medium, Large and Giant. Let’s look at the size categories first.  I’ve picked examples of a well known breed in each category to give you an idea.

Toy dogs

The example given here is based on the growth rate of a Toy Poodle.

Dogs of this kind of size and weight typically stop growing somewhere between 6 and 8 months of age, but the vast majority of their growth is complete by around six months of age.

Small and medium dogs

The example given of a small dog is based on a Miniature Schnauzer. The medium dog is an English Springer Spaniel.

Bear in mind that Springers come in a wide range of sizes, from very small working bred dogs to the larger chunkier show type.

We’ve picked a moderately sized Springer for the purposes of this illustration.

Small to medium sized dogs tend to have completed their growth by around the end of the first year, with close to their adult height reached by around nine months.

Again, this is not set in stone. Just a rough guide.

Large Dogs

In this example the growth rate of the large dog is based on the growth rate of a moderate sized German Shepherd Dog.

Most larger breeds will finally complete their growth somewhere between 18 and 24 months, though they may be close to their adult height by their first birthday.

Giant Dogs

Our Giant Dog is a Great Dane. Some giant breeds reach even greater weights than this and grow for even longer.

Some giant breeds will continue growing for up to three years.

Again, these are general guidelines. But the general rule is this: the larger the dog, the longer he grows for.

Breed size is not the only factor influencing growth. Gender has a role to play too.

Differences between male and female puppies

Our graphs and charts show an average dog. Male dogs are usually a little heavier and larger than female dogs of the same age and breed.

So females may be lighter than our chart suggests, and males may be heavier.

These differences can be quite substantial in adult dogs from the larger breeds, but are less noticeable in smaller breeds and in very young puppies.

Piling on the pounds?

Remember also that some dogs will carry on growing for a little longer than the guidelines above.

But if a dog is still piling on the pounds long past the point where other dogs of his size has stopped growing, you need to ask yourself some questions, such as “am I overfeeding my dog” and maybe get him a check up with your vet.

While gender may affect your dog’s final size, there is nothing you can do about it.

There are quite a few factors though that can affect how fast your puppy will grow or long your puppy will grow for, which are at least partly within your control. They include:

  • Neutering
  • Diet
  • General health

How neutering affects growth

Neutering affects the final size of your dog because your dog’s sex hormones are involved in telling your dog’s body to ‘stop growing’.

A dog neutered before he stops growing, may carry on growing for longer because he lacks the sex hormones to switch off that growth. So a neutered dog may end up taller than his entire brothers or sisters.

This continuation of growth is not to the dog’s advantage and may predispose the dog to joint problems. Several quite large recent studies have shown that neutered dogs are more likely to suffer from cruciate ligament tears and from hip dysplasia.

You can find out more about this in my articles on neutering.

Weight gain?

Many experts believe that neutering may also impact on your dog’s appetite, though not everyone agrees on this.

I found my own male dog required less food after neutering, but that my female dogs did not seem to be affected. But I have only neutered a few of my dogs so it isn’t a good sample.

In any case neutering should not affect your dog’s body weight in any way provided that you adjust how much food you give him according to how he looks and feels. (More on that in a minute).

Feeding and growth

Despite the fact that the impact of neutering is not relevant if you adjust your dog’s food intake accordingly, many people really struggle with this.

Which brings us to the role of diet in your puppy’s growth and development.

Underfeeding puppies

Not many puppies are underfed these days, but it does happen. More often, puppies are malnourished because people are feeding them inappropriately, rather than simply not feeding them enough.

Sometimes this is a cultural thing. For example, in some societies people eating vegetarian diets for religious reasons are reluctant to feed their dogs any form of meat.

This can lead to puppies being fed an inappropriate diet of vegetables and grains. Poor growth and other health problems are likely if puppies are not fed a balanced diet suitable for a carnivore.

We tend to think of malnutrition as being feeding the wrong things or starving a puppy, but overfeeding is a form of malnutrition too.

Speeding up your puppy’s growth rate

Sometimes people ask me if it is possible to speed up their puppy’s growth rate or make him grow bigger.

The answer is yes, it is, but it is not necessarily a good thing.

An underfed puppy may benefit from overfeeding for a while, though this needs to be done with care if you want to avoid digestive problems.

But a healthy puppy that is fed more than he needs will simply get fat.


This is your window into the world of puppy growth and development. We begin on the day your puppy is born.

Week 1

Your puppy is born fully furred but with his eyes and ears closed so he cannot hear or see. His front feet are strong and he can pull himself towards his mother with them.

He can cry if he is uncomfortable and his mother will respond to his cries by moving him towards her and licking him.

Your puppy spends most of his time sleeping or suckling. If orphaned he’ll need feeding by hand every two hours!

He cannot regulate his own body temperature and needs his mother for heat, or an artificial heat source.

If he is going to be docked, this procedure will take place in the first two to three days. In the first week to ten days of his life your puppy grows rapidly and will double his birth weight.

Week 2

During this week, your puppy’s eyes will start to open. He probably can’t see very much yet. His forelegs are getting much stronger. He’ll continue to grow rapidly, adding 5-10% of his body weight.

The puppies’ mother is constantly attentive, only leaving her babies to eat or for toilet purposes.

She licks the puppies bottoms to stimulate a bowel or bladder movement and eats the result. There is no cleaning up to do yet.

The breeder will begin to handle the puppies more though, and get them used to human contact. She will worm the puppies for the first time at the end of this week.

Week 3

During this week a lot happens. Puppies begin to get their personalities.

Your puppy can stand and sit up by the end of the week. Tails can be wagged, ears will be completely open and puppies start play growling and interacting with their litter mates.

Your puppy can regulate his body temperature more effectively and will start to cut his first teeth in preparation for weaning.

The front teeth, canines and incisors are cut first. Toward the end of the week he may have his first tiny taste of puppy food.

Week 4

This is the week that puppies become really active and strong on their legs, and play actively with one another. They also start to move away from the sleeping area to empty their bowels and bladder. They may try to climb out of the whelping box.

The puppies’ mother will start to spend more time relaxing away from the puppies. She will gradually stop cleaning up after the pups, that is now the breeder’s problem!

If she lives indoors, she may rejoin the family for more of each day.

Your puppy will cut his back teeth and the breeder will get weaning underway this week and by the end of it, your puppy will be getting quite a bit of his nourishment from puppy food. She will also worm the puppies a second time.

If the mother is allowed near the puppies after she has been fed, she may regurgitate her dinner for them. This is completely natural and normal.

Week 5

Your puppy can now really run and play. He is a proper little dog. Rolling around with his brothers and sisters and playing with toys.

He can bark too and some puppies can be quite noisy at this age! He chases after his mother whenever she appears and suckles hungrily, but she is starting to get fed up with it, and may be reluctant to feed her brood for very long.

His mother is teaching him not to bite too hard. And his breeder is introducing him to lots of new experiences so that he won’t be afraid of them later.

If he lives in outdoor kennels he should spend part of each day indoors with the family.

Week 6

By the end of this week most puppies are fully weaned, and eating five or six little meals of puppy food each day.

Your puppy may still suckle from his mother, but he doesn’t need to.

From now on, a small breed puppy may gain around 5 ounces a week in weight, whereas a large breed puppy puts on a massive 21/2lbs.

Week 7

Some puppies go to their new homes towards the end of this week – many puppies show the beginnings of fearfulness at this point and will startle or jump at strange sounds an sights.

Socialization must begin in earnest. Your puppy’s mother continues to teach him bite inhibition when she visits him to play.

Week 8

This is normally the week when your puppy leaves his first home and joins his forever family.

He is now two months old and ready for his new life. From now on, we’ll be looking at your puppy’s development month by month, from three to eight months.

Month Three

From eight to twelve weeks is a very important period for puppies. It is the time during which they become fearful of anything unfamiliar and need to be thoroughly socialized.

It is also the time during which most puppies get to grips with house training, learning to wait before eliminating and start sleeping through the night without a potty break.

It is a busy time for new puppy owners. Your puppy will have his vaccinations during this month.

Biting can be a big problem during this stage and you need to be patient and consistent in order to teach the puppy not to hurt people when he plays.

Provided you use force free methods, this is a great time to get puppy training under way, and especially to teach a puppy recall, and to get your puppy used to working with food. You’ll be feeding him four times a day, and/or using much of his food in training

Handle your puppy all over, every day. If he is a long coated breed he will need regular grooming and although he won’t have much coat yet, now is the time to begin.

Month Four

Most puppies can drop down to three meals a day at twelve weeks old. This means slightly larger meals, so watch your puppy doesn’t get an upset tummy.

And at twelve weeks, if you take a small breed puppy’s weight in pounds, divide it by his age in weeks, and then multiply by the number of weeks in the year, you will have a rough idea what your puppy’s final weight as an adult will be.

So, for a 2.5lb puppy at twelve weeks the formula will be (2.5/12) X 52

Calculate the bit inside the brackets first. You can do the same calculation for medium pups at sixteen weeks and large breed pups at 20 weeks – just divide his weight by his age in weeks before you multiply by 52.

From twelve to sixteen weeks puppies start to lose that very young puppy ‘look’ and more closely resemble a miniature version of their adult selves. Medium to large pups will reach about half their adult height by the end of the month.

Puppies under four months don’t need formal walks, just lots of opportunity to play and run around in your garden or yard.

If the weather is warm you can get your puppy swimming now.

Most dogs swim instinctively, but don’t allow brachycephalic puppies to swim unsupervised – some are not able to swim at all.

You’ll enjoy training your puppy now as he is getting more attentive and can concentrate for longer. He should be able to come when he is called, in and around your home, provided there are not too many distractions.

He’ll probably understand sit, touch your hand on cue, and perhaps be able to sit in his basket for a few seconds when asked. It all depends on what you have taught him.

Month Five

Your puppy will start losing his baby teeth from around four months of age. He’ll probably have a more adult coat by the end of this month.

He may still be chewing a lot and biting too. Use frozen kongs to help him and give your furniture and fingers a break.

Puppies can go for short walks now. By the end of this month your puppy could have a twenty minute walk each day. He may also enjoy fetching a ball and playing with other dogs, but take care to stop before he gets very tired. And don’t walk brachycephalic puppies very far, or in warm weather.

This is the month during which some puppies start to become less dependent on their humans for security. Keep your puppy close to you outdoors by changing direction frequently so that you puppy has to keep coming to find you. And engaging him in games.

Reward your puppy generously for ‘checking in’ with you on walks. The foundations of a great recall are often build or spoilt during this month.

If your puppy knows how to sit or lie down at home, start some simple proofing exercises with him in public places. And start teaching him to ‘stay’ for short periods of time.

Month six

A healthy puppy can usually manage on two meals a day from around six months. During this month a Retriever, Spaniel or GSD puppy will reach around two thirds of his adult weight.

A Great Dane and other large breeds will have reached about half their final weight and little dogs will have almost completed their growth.

Some female dogs will come on heat for the first time during this month, or the next, so keep an eye open now for swelling of her vulva and any discharge.

Your dog will become increasingly confident over the next few months so practice, practice and practice that recall! Make it a habit he cannot break. And be generous with your rewards.

Month Seven

By the end of this month, your puppy will have all 42 of his adult teeth and be looking quite grown up. Small breed pups may now be more or less mature.

Your puppy will enjoy half hour off lead walks now, and should be able to walk on a loose lead for short periods with plenty of encouragement and rewards.

Keep practicing that recall! Teach your dog to recall away from all kinds of interesting things such as ‘other people’, other dogs, frisbees, etc.

Month Eight

Unless you have had your puppy neutered he now has plenty of sex hormones zooming around his system.

These help to slow his growth further and to build his confidence.

Make sure you practice good outdoor management on walks to maintain the good recall you have built and work hard on thoroughly proofing all his obedience skills.

Nine months and beyond

Many female dogs will be neutered once they have completed their first season. Read our information on neutering before you take this important step, for dogs of either sex.

Once your dog is a year old he can participate in more strenuous activities and sports.

Now is the time to think about the kinds of activities you would like to do with him – go jogging together for example – and if necessary, to start to get him fit.