A lethargic dog should stop devoted dog owners in their tracks—lethargy in dogs is often one of the earliest clues that something isn’t quite right. Integrative veterinarian Dr. Julie Buzby explains how to recognize a lethargic dog and shares 19 medical reasons why your dog may be lethargic. Then she explains when you should take a lethargic dog to the vet.
From a wagging tail to pleading eyes, your healthy dog is skilled at telling you how he or she feels without using a single word. But did you know your dog is also communicating with you when he or she is acting lethargic?
It turns out that sluggishness, listlessness, and loss of energy are your dog’s ways of telling you that he or she may need a trip to your vet—not just a nap. Let’s take a closer look at lethargy in dogs and what it could mean for your precious pup.
- What is lethargy in dogs?
- How do you tell if your dog is lethargic or just tired?
- What are the symptoms of a lethargic dog?
- Why is your dog acting lethargic? 19 possible causes
- 1. Kidney disease
- 2. Liver disease
- 3. Pain
- 4. Anemia
- 5. Heart disease
- 6. Diabetes mellitus
- 7. Infectious diseases
- 8. Medications
- 9. Pneumonia or other respiratory infections
- 10. Cancer
- 11. Endocrine diseases
- 12. Toxins
- 13. Parasites
- 14. Dehydration
- 15. Neurologic disorders
- 16. Bites or stings
- 17. Trauma
- 18. Anxiety
- 19. Allergies
- When do you need to take a lethargic dog to the vet?
- If your dog is lethargic, call your vet
- How do you tell the difference between your dog having a sluggish day and something more concerning?
What is lethargy in dogs?
The term “lethargy in dogs” refers to a lack of energy, loss of interest in doing daily activities, or reluctance to get up and move about. Lethargic dogs may seem to suddenly lay around all day. They may not want to play, or they might generally seem a bit tired and depressed.
However, it is also possible for a dog to have a decreased activity level if he or she is just tuckered out from a busy day. So how do you know if what you are seeing is a sign of lethargy?
How do you tell if your dog is lethargic or just tired?
When trying to recognize lethargy in dogs, it can be helpful to think through the events of the past few days. Did your dog have a doggie play date with his or her friends? Did you take your normally sedentary pup on a long run or walk?
In these situations, your dog might understandably be more tired than normal. But typically even a tired dog will still get excited about a favorite treat or the doorbell ringing. And after about 24 hours, your dog should be back to his or her normal self.
On the other hand, if you can’t think of anything that might have worn your dog out, or he or she doesn’t quickly bounce back after some rest and relaxation, your dog might be lethargic.
What are the symptoms of a lethargic dog?
In order to determine if your dog is tired or lethargic, it can also be helpful to know the symptoms of lethargy in dogs. Since lethargy in dogs is a general lack of energy or a feeling of sluggishness, you may notice:
- Your senior dog hesitates to go for his or her usual walk.
- He or she stays in one place for a prolonged time.
- Your dog ignores his or her favorite toys and has no desire to play.
- When you call him or her, your dog fails to come.
- Your dog sleeps more than usual.
- Your dog may stand up and move around but quickly wants to go lay back down again.
- The things that normally excite your dog (e.g. visitors, favorite treats, etc.) get a lackluster response.
- Your dog wears out faster than normal from activity.
Is your dog showing other symptoms?
In addition to watching for these signs of lethargy, it can be helpful to pay attention to any other signs that something might be wrong. Sometimes all you notice is that your dog seems low on energy. But often, a lethargic dog will have other symptoms. For example, you might notice:
- Your dog is lethargic and wobbly
- Your dog is lethargic and not eating (however, it’s also possible for your dog to be lethargic but eating and drinking)
- Your dog is lethargic and shaking
- Your dog is vomiting and lethargic
- Your dog is drooling and lethargic
- Your dog is lethargic and drinking a lot of water
- Your dog is lethargic and breathing hard or lethargic and panting
- Your dog has pale gums and lethargy
- Your dog has diarrhea and lethargy
Especially if your dog becomes suddenly lethargic for no obvious reason and/or is showing some of the symptoms above, you should call your vet. (We’ll talk more about how to decide if you need the regular vet or vet ER in a bit). Lethargy is a common symptom of many different medical conditions, so it is nothing to be ignored.
Why is your dog acting lethargic? 19 possible causes
When thinking through the causes of lethargy in dogs (and there are a lot!), the following 19 medical problems come to mind as being some of the top contenders. However, be aware that this is far from an exhaustive list.
1. Kidney disease
In kidney failure in dogs the kidneys are functioning poorly and cannot excrete as many toxins and waste products as they normally would. When these compounds build up in your dog’s bloodstream, he or she often begins to feel sick and lethargic. And your dog may experience other signs like weight loss, vomiting, diarrhea, and loss of appetite. These signs may become especially prominent as he or she progresses through the stages of kidney disease in dogs.
2. Liver disease
When a dog’s liver is damaged, it can’t do its jobs as well, including storing energy for later use. This can lead to lethargy. Plus, dogs with liver disease may experience vomiting, diarrhea, and a lack of appetite. So they can be lethargic simply because they don’t feel good.
Liver disease in dogs can be caused by infection, chronic inflammation, toxin ingestion, congenital diseases, and tumors. To diagnose liver disease, your vet will use blood tests for dogs to look for high liver enzymes in dogs such as high ALP in dogs.
3. Pain
A reluctance to participate in normal activities or sleeping more than normal can be a sign your dog is in pain. And so can withdrawing from the family, being more irritable, altering the posture or gait, or eating less than normal.
Since pain is one of the common causes of lethargy, let’s take a look at some of the potential sources of pain:
Orthopedic problems such as arthritis
Osteoarthritis in dogs, a torn ACL in dogs, hip dysplasia in dogs, or other orthopedic conditions can all cause joint pain and poor mobility. As a result, your dog may prefer to lay in one place, not want to take walks, struggle to get up and down, or avoid stairs or jumping.
The good news is that there are many options for natural pain relief in dogs, as well as a variety of pain medications (e.g. carprofen for dogs or gabapentin for dogs) to relieve arthritis pain in dogs (or manage other causes of joint pain). And you can take steps to help your senior dog with arthritis at home and comfort a dog who is in pain.
Eye problems
Some eye conditions such as glaucoma in dogs, uveitis in dogs, or corneal ulcers in dogs, may cause significant ocular pain. This pain, especially when it persists for a long time, like in glaucoma, can cause a dog to be lethargic.
Dental disease
Sometimes dogs with dental disease in dogs or a dog tooth abscess may be lethargic because their mouth hurts. Thankfully, a dog tooth extraction and dental cleaning often help them feel better in no time.
Pain from internal organs
Pancreatitis in dogs (i.e. inflammation of the pancreas) can cause severe abdominal pain as well as vomiting, diarrhea, and lethargy. And so can other conditions like a gall bladder mucocele in dogs.
4. Anemia
Anemia in dogs (i.e. a low red blood cell count) can lead to lethargy. This is the case because red blood cells carry oxygen to the rest of the body. So when a dog has fewer red blood cells, his or her body may not be getting the oxygen it needs to function optimally.
The causes of anemia in dogs are numerous. But some of the most common include:
- Blood loss (due to parasites, trauma, GI bleeding, or cancer such as hemangiosarcoma in dogs)
- Kidney disease or other chronic conditions
- Immune mediated hemolytic anemia (IMHA in dogs) and immune-mediated thrombocytopenia (ITP in dogs)
- Toxins
- Bone marrow diseases or cancer
5. Heart disease
When a dog develops heart problems like heartworm disease in dogs, dilated cardiomyopathy in dogs, mitral valve disease in dogs, or congestive heart failure, the heart cannot pump blood through the body as effectively as it should. This results in lower levels of oxygen throughout the body and backup of blood in the vessels.
Over time, heart disease in dogs may cause signs such as weakness, coughing, exercise intolerance, lethargy, collapse, and difficulty breathing.
6. Diabetes mellitus
In diabetes in dogs, the glucose (i.e. sugar) molecules can’t get into the cells to be used for energy due to a lack of insulin (i.e. the hormone that lets glucose into cells). This lack of cellular energy and the high blood sugar levels lead to lethargy, increased thirst in dogs, increased urination, a dog who is losing weight but eating well, and other symptoms.
In severe cases, diabetic dogs can go into diabetic ketoacidosis (i.e. DKA in dogs) which can be life-threatening. Dogs with DKA tend to have more severe signs such as vomiting, diarrhea, collapse, or weakness in addition to the typical signs of diabetes.
7. Infectious diseases
Often when a dog has an infectious disease like leptospirosis (lepto in dogs), distemper in dogs, or parvovirus, he or she may be lethargic. Additionally, depending on the disease, you may notice signs such as fever, vomiting, diarrhea, weakness, nasal discharge, coughing, dehydration, etc.
8. Medications
Sometimes lethargy can be a side effect of certain medications. This is especially common with medications used to manage seizures in dogs, decrease anxiety, or control pain. For example, one of the most common gabapentin side effects in dogs is severe lethargy that usually decreases after a few days on the medication.
9. Pneumonia or other respiratory infections
Kennel cough and canine influenza are two of the most common causes of respiratory infections in dogs. Both are highly contagious but typically remain mild. However, they can occasionally lead to pneumonia in dogs, which tends to make dogs much sicker and more lethargic. Plus, a variety of other bacteria, viruses, and fungi, as well as aspiration of food, water, or vomit, can cause pneumonia.
In general, lethargy plus coughing and sneezing, nasal discharge, and/or your dog breathing fast could be signs your dog has a respiratory infection.
10. Cancer
A variety of different cancers (e.g. liver cancer in dogs, osteosarcoma in dogs, prostate cancer in dogs, bladder cancer in dogs, lymphoma in dogs, etc.) can affect dogs. As a result of the toll cancer takes on their bodies, dogs with cancer won’t have as much energy as they used to. And they tend to sleep more.
11. Endocrine diseases
The endocrine system produces and secretes hormones through the body to control various processes. When there are too few or too many hormones being secreted, it can lead to diseases like:
- Hypothyroidism in dogs (i.e. low thyroid hormone levels)—May lead to weight gain, lethargy, and a poor hair coat
- Cushing’s disease in dogs (i.e. high levels of the steroid hormone cortisol)—Symptoms include increased thirst, urination, and appetite plus changes in hair coat, a pot bellied dog appearance, and lethargy.
- Addison’s disease in dogs. (i.e. a deficiency in cortisol and/or mineralocorticoids)—May cause vague signs like lethargy, weakness, collapse, vomiting, or diarrhea.
12. Toxins
Ingesting toxins (e.g. your dog eats a grape or raisin or your dog gets into Advil) can sometimes cause lethargy. Plus, you may see other symptoms such as vomiting, diarrhea, weakness, collapse, tremors, seizures, etc.
Important note: Time is of the essence when it comes to toxins. So if you ever think your dog may have gotten into something toxic, please call your vet, ASPCA Animal Poison Control Center, or Pet Poison Helpline immediately. (There is a fee associated with calling both pet toxicology services but it is well worth it.)
13. Parasites
Some internal and external parasites (e.g. hook worms, fleas, and ticks), feed on your dog’s blood. This can cause lethargy due to anemia. Plus, dogs (especially puppies) who have a heavy burden of roundworms could potentially be lethargic because the parasites are stealing so many nutrients from the GI tract.
14. Dehydration
If a dog becomes dehydrated from profuse vomiting and/or diarrhea, fever, significantly decreased water intake, or an underlying medical condition (e.g. diabetes, kidney disease, etc.), he or she may be lethargic.
15. Neurologic disorders
Lethargy, decreased response to stimuli, or depressed mentation can also occur with some neurologic disorders. For example, if a dog is in the post-ictal phase (i.e. time directly after a seizure), he or she may be confused, disoriented, or more tired than normal. These changes may clue you into a seizure even if you didn’t see it happen.
16. Bites or stings
A snake bite on a dog can cause a dog to become weak and collapse. Plus, you may notice a wound on your dog, difficulty breathing, excessive drooling, swelling, or other symptoms.
Additionally, dogs who are having a severe reaction to an insect bite or sting may also show similar signs.
17. Trauma
Trauma, such as occurs after a fall, dog fight, or being hit by a car, can cause lethargy in dogs. Some dogs have primarily external injuries (e.g. fractures, wounds, etc.). But other dogs may suffer significant internal injuries (e.g. air in the chest cavity, bruised lungs, internal bleeding, brain bleeding or swelling, etc.).
18. Anxiety
While it might sound counterintuitive, anxiety is another cause of lethargy in dogs. Dogs who are anxious may pace and engage in destructive behaviors. Plus, worried dogs might be panting and restless for a good part of the day. Heart beating rapidly, anxious dogs are in a permanent state of “fight or flight,” which expends a lot of energy.
This is especially true for dogs with separation anxiety because they experience these feelings all day long. Anxiety can wear dogs out and may explain why your dog seems tired once you’ve come home.
19. Allergies
Allergic dogs are constantly itchy, which can make them mildly lethargic. And they may suffer from secondary infections such as otitis in dogs (i.e. ear infections), pyoderma in dogs (i.e. bacterial skin infection), or dog paw yeast infection. These problems can make them feel even worse.
Thankfully, whether your dog is allergic to something in the environment, fleas, or dog food, there are a myriad of allergy medicines for dogs that can help give your dog some relief.
When do you need to take a lethargic dog to the vet?
It isn’t always a cause for alarm if your dog is a bit more tired than normal. But as you have learned, lethargy can be a sign of many different problems—some more serious than others.
If your dog is just mildly lethargic (perhaps slightly less interested in doing daily activities or a bit more subdued), you have more leeway to observe your dog. It is possible that he or she may perk up in a day or two. But if not, it is a good idea to make a vet appointment.
Signs your dog needs veterinary care
On the other hand, if you have noticed a significant change in your dog’s energy level and/or your dog is showing other symptoms, now is the time to seek veterinary attention. Some symptoms of concern include:
- Vomiting
- Diarrhea
- Change in water consumption
- Increased or decreased appetite
- Sudden weight loss or gain
- Limping or other signs of injury
- Coughing or sneezing
- Trouble breathing
- Seizures or disorientation
- Weakness or collapse
- Signs of pain
- Pale gums
This is far from an exhaustive list. So keep in mind that if you are worried about your dog, the best thing you can do is contact your vet.
Do you need to go to the ER or your regular vet?
If your dog is experiencing severe symptoms (e.g. profuse vomiting and diarrhea, seizures, collapse, extreme weakness, difficulty breathing, etc.), you may need to make an emergency vet visit. Otherwise, you are probably fine to make an appointment with your regular vet within a day or two.
Resources to help you make a decision
I know figuring out if you should take your dog to the vet can be stressful. So I want to remind you that you don’t have to sort this out alone. If you’re unsure whether you should head to the ER or to your regular vet, you can always call your vet for advice. The veterinary team would be happy to direct you to the place that is right for your dog. Plus, my article “How to tell if your dog sick” can also provide some helpful guidance.
If your dog is lethargic, call your vet
There are so many causes of lethargy in dogs (far more than we have time or space to talk about here). With that in mind, the best advice I can give you is that if you aren’t sure if your dog is lethargic or just tired, call your vet for advice. And if you know your dog is lethargic and you have concerns about his or her health, make an appointment with your vet or seek emergency veterinary care.
In the end, it is better to be proactive and get your dog checked out. If you are worried about your dog, make an appointment with your vet and share your observations. That way you can ensure you are doing all you can to keep your dog happy and healthy for as long as possible.
How do you tell the difference between your dog having a sluggish day and something more concerning?
Please share your experience in the comments below.
My nine month old Australian shepherd suddenly became lethargic & sleepy tonight. Totally not herself. No other symptoms. Should I take her to an emergency vet?
Hi June,
I am sorry your puppy is experiencing these worrisome symptoms. Anytime there is a sudden change in behavior, especially in a young puppy, I would recommend you reach out to a vet right away. I am not sure if this is an emergency, but without examining her myself, there is no way to know. I like to err on the side of caution and encourage you to call your local ER and see if they want you to bring her into the clinic. Praying all is well.
My dog is very energetic and has a lot of anxiety. We went for a 20 minute walk yesterday and as soon as we got home she started shaking, tail between her legs and ears down. She has been drinking and not eating. I woke up today and she didn’t want to go for a walk, but finally got her to go outside. No walk through and she loves walks. Her poop was solid and she peed. She has been moaning a bit and just interested in sleeping. She is only 6. It is Sunday so I have to wait until Monday for the vet. Any thoughts?
Hi Tammy,
I understand your concern for your pup and think it is good you are reaching out for advice. Unfortunately, without examining her myself, there are just too many possible causes to make specific conclusions. I agree it is best to contact your vet as soon as possible. The symptoms you describe could be signs of something very serious. Hoping you were able to get answers and start treatment right away. Praying all is well and wishing your sweet girl all the best.
Hello,
Last night my 11 year old terrier/chihuahua/poodle mix ate a small piece of fried fish that fell to the floor. I don’t believe there were any bones in it but I can’t say for certain.. A few hours later she started to act strange. I saw her just standing on all fours in the same spot for several minutes not moving at all. She wouldn’t even lay down. She was also shaking a bit. She did follow me around the house very slowly and then I started petting her to comfort her. She eventually laid down and seemed very listless. She is a very energetic dog and is always zooming around even though she is 11 yrs old. Today she won’t move from her sleeping spot and just wants to sleep.. She won’t eat or take in water. She hasn’t vomited or have diarrhea. Actually she hasnt gone to the bathroom at all. Is it possible the fish caused an upset stomach or perhaps there was a small bone in the fish and is lodged somewhere?
Hi Crystal,
I understand your concern for your little pup with how quickly these symptoms emerged. It is very possible that the fish caused some GI upset or even pancreatitis. Fish itself is very healthy but the oil it was fried in may be the culprit. It would be best to get your girl to the vet as soon as possible to make sure you get things under control before they escalate. Hoping all is well and she was able to make a full recovery. Feel free to leave an update and let us know how she is doing. Best wishes!
My dog has been lethargic for the past few days. This started around Sunday afternoon where he was not as energetic as usual. This is odd because he is not even 3 years old and he is a Korean Jindo. He has barely eaten since then. He recently vomitted once today and the color was yellow. I’m scheduled to meet the vet tomorrow, but I’m worried as he is my first dog ever. He is usually playful and energetic. He also whines sometimes while he is laying down. He has also been eating grass whenever I take him outside for potty. He does urinate but he hasn’t pooped since Sunday.
Hi Benjamin,
I understand your concern for your pup, and I agree these symptoms are very worrisome. I am glad you had already planned to have him evaluated by your vet. Hoping you were able to get answers and there was a clear path forward with treatment. Praying all is well and wishing you both nothing but the best!
Hello.
My 9 year old maltese shihtzu Sophie has all of a sudden become lethargic and looks dopey (her eyes move slowly and when she looks at any of us, she struggles to keep her eyes open).
She also sometimes shakes, mainly in her leg but she doesn’t have any walking issues or seeming like theres ang pain. No issues lifting her leg for a belly rub and she had a walk around the park (usually she is so energetic but today she did walk around but at a slower rate).
She wont eat any dinner or snacks, and only wants to drink water from our hands rather than the usual bowl. Her nose is dry and her skin does feel quite warm.
Its really out of the ordinary for her, as she is a dog with so much personality and even some attitude, so seeing her so low energy and lethargic is confronting.
It’s easter long weekend, so I’m not sure if we can get her in to see a vet at all and not sure how seriously to take it. Do you have any ideas on what this could be?
Thanks so much
Laura
Hi Laura,
I understand your concern for Sophie with the worrisome symptoms she is exhibiting. Without personally examining her it is hard to make specific conclusions or recommendations. From what you describe, this could be something very serious. I think it would be best to take her to the vet as soon as possible. If her condition continues to decline, it may be necessary to seek the services of an emergency clinic. Hoping she was able to make a full recovery and praying all is well.
Hello, about a month ago my 12-year-old pit bull got a bad skin infection from flea bites and was put on antibiotics. That completely cleared up, but within the past two weeks she has lost some weight and isn’t as interested in eating her dry dog food. I have tried a few things like putting some canned pumpkin in her food which helped. She has thrown up a meal here and there though. Now, she threw up her dinner last night and her breakfast this morning. Then after that she threw up some bile. It is Thursday and I cannot get her into the vet until Monday. She will get up and walk around but she is a lot slower and wobbly and lays down all the time. Do you think she will be okay until Monday? I am giving her stomach a rest and have some boiled chicken and rice that I am going to try and feed her tonight or tomorrow morning. Any advice helps. Thank you.
Dear Kristi,
I understand your concern for your senior pup with these worrisome symptoms. I agree this has me very concerned as well. I am not sure this is something that can wait till Monday. Of course, without examining her myself I can’t make specific conclusions. But what you describe could be signs of a life-threatening condition (such as an intestinal blockage or even internal bleeding which is usually from a ruptured mass on the spleen). I encourage you to get your girl evaluated by a vet as soon as possible. That may require an emergency visit, but I’d rather be safe than sorry and err on the side of caution. Hoping all is well and praying for a positive outcome for you and your pup.
My 9-year old Maltipoo is suddenly lethargic. She wants to sleep. She snaps if yo try to move her, etc. She rubs the side of her face on the door edge. I noticed swollen glands under her neck. For a couple of days she wants to be alone. When she was outside, she didn’t want to come in the house. Could this be cause by a dental problem. Her lethargy was better yesterday and worse last night. She started walking with her tail down.
Hi Charles,
I understand your concern for your little pup. Without examining her myself, it is hard to make specific conclusions. What you describe could be caused by a dental problem, but to know for sure you would need to schedule an appointment with your vet. Since your girl is exhibiting signs of pain and lethargy, I would encourage you to have this addressed sooner rather than later. Things can sometimes progress quickly, and I don’t want this to turn into a life-threatening situation. Hoping you can get the answers you need to restore your dog’s health and well-being. Feel free to leave an update as things unfold.
Our 4 year old Rottweiler is currently very lethargic. She has always had bouts of lethargy after her season but this time it is going on and on. Her appetite is fine, even a bit excessive, and she is capable of short bursts of activity, usually at home or in the gardens. She has no enthusiasm for her walks, however.
The vet has prescribed her Rimadyl, for an old injury to her left front paw which sometimes plays up, but this doesn’t seem to be working this time.
She has had recent upheaval in her life: she originally belonged to my niece and partner, but a baby came along, niece moved house 6 months ago,and left Willow with me to care for her. She saw my niece yesterday and became very excited and clingy. Could separation be playing a part in this problem, I wonder?
Hi Ed,
I understand your concern for your Rottweiler. From what you describe, I do think depression from being separated from your niece could be the culprit. In these situations, before I assume a behavioral cause, I like to rule out medical issues. I would recommend you talk to your vet about checking some routine lab work just to be sure nothing is missed. If the results are normal, then maybe you can discuss trying a course of medication to help with the depression. I know Willow has not experienced the death of a housemate, but to her it may feel like she is grieving a loss. Here is a link to another article that may offer some insight: Do Dogs Grieve? Helping Your Dog Cope With Loss
Hoping you can find a way to get your girl back on track and living her best life. Wishing you both brighter days ahead and praying for a positive outcome. ♥
My 11 year old baby was put in oxygen for 3 days due to congestive heart failure. After 3 days he was sent home with 7 pills. When he came home he was happy, breathing well, and ate a bowl of chicken. After a big struggle giving him his pills wrapped in food, peanut butter, ice cream, he won’t eat and is afraid of us. He’s only drinking water. We are at our wits end. Can you please help?
Hi Linda,
I am sorry your senior guy is experiencing so much anxiety with taking his medications. Please make sure your vet is aware of this issue. While his behavior may be due to the anxiety, it could also be a sign of his heart condition worsening. Your vet may need to schedule a recheck just to be sure there are no other problems contributing to these symptoms. Then they may be able to switch your dog’s medications to a liquid form or have them flavored so they are more appealing. In the meantime, here is a link to another article with more tips and tricks to try and get your boy to take his pills without all the struggle: Your Dog Won’t Take Pills? 5 Easy Solutions for Uncooperative Pooches
Wishing you all the best and hoping for an easy solution.
About an hour or 2 after my dog ate about a handful of cooked chicken with her food last night, she started to become unwell.. I think the chicken may have been too old, but it didn’t smell or anything. She is very lethargic, She hasn’t thrown up or had diarrhea. She is having difficulty with walking up and down the stairs. She is very cautions and slow. She is still drinking and still eating her treats. Could it just be a mild cause of food poisoning?
Hi Tara,
I understand your concern for your dog and what you describe has me worried too. I am not sure exactly what could be causing this sudden change in behavior, but it sounds like it could be an emergency situation. Please call your vet right away and see if they want you to bring your girl in for an exam. Hoping all is well and wishing you both the best.