Is my dog sick? 10 warning signs that your dog could be unwell

Is my dog sick? A female vet giving a small brown dog a health check
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Is my dog sick? It’s a question no canine owner wants to worry about but happens to the best of us. You can wrap your dog up in cotton wool, feed them all the right food, and ensure they get adequate amounts of play and sleep and they can still get unwell. 

While it’s not always in your power to prevent it, you can keep an eye out for some tell-tale warning signs. Perhaps you’ve already spotted some reasons for concern such as your dog isn’t playing with his best puppy toys or he’s eating less or more than usual. But a dog feeling unwell isn’t always obvious so we spoke to Dr Elizabeth Racine, a general practice veterinarian, to find out how to identify if your dog could be sick. Small animal veterinarian, Dr Jo Woodnutt, also offered her expert advice on how to identify if your dog is sick or feeling low.

Spotting early signs of illness is important as this means you can seek help from a vet as soon as possible and speed up the recovery process. If you’re looking to decide if your dog is sick or is just having an off day read this vet’s guide to 10 signs your pup is ill and needs medical assistance to get better.

Elizabeth Racine
Elizabeth Racine

Dr. Elizabeth Racine is a small animal general practice veterinarian with a bank of knowledge on all things pet health and wellness.  She is especially interested in veterinary behavior, nutrition, and internal medicine. Dr. Racine also has experience writing content for the American Kennel Club, Merck Animal Health, Bayer PetBasics, Elanco, and CareCredit. 

Dr Joanna Woodnutt BVM BVS BVMedSci MRCVS
Dr Joanna Woodnutt MRCVS

Dr Joanna Woodnutt qualified as a veterinarian from the University of Nottingham where she then went on to practice companion animal medicine in the Midlands. She really took to the consulting side of things and helping clients with medical problems such as dermatology, behaviour and nutrition - anything that involved helping clients understand their pets better.

10 signs that your dog may be sick

1. Vomiting

Just like us humans, dogs can get an upset stomach once in a while. It’s common for dogs to snack on things they shouldn’t – like that dead frog out in the yard or those tasty chunks in the cat’s litter box – and this can naturally lead to some digestive upset. But if your dog’s vomiting lasts for more than 24 hours, or is accompanied by other symptoms such as abdominal pain, fever, loss of appetite, or diarrhea, it could be a sign that your dog is sick, and needs to see a vet. Vomiting is especially concerning if you notice anything other than food – like blood or bits of foreign material like plastic or cloth in the vomit.  Unproductive retching – when your dog tries to vomit but can’t produce anything at all – is often a sign of an emergency situation and should be addressed immediately.  If you’re concerned, take your dog to your vet or the local emergency hospital right away.   

2. Diarrhea

Most dogs experience a little diarrhea at some point in their lives, but some cases can be more severe than others. Diarrhea in dogs can be caused by dozens of different conditions, including parasites, infections, dietary indiscretion, or even cancer. Most cases of diarrhea resolve on their own in 24-48 hours. If your dog’s diarrhea is persistent, profuse, or bloody, then you should see a veterinarian right away. Your vet may ask you to bring along a sample of the diarrhea, which can be used to test for parasites and some other illnesses if necessary. Once the underlying cause of your dog’s diarrhea is diagnosed, your vet will be able to prescribe appropriate treatment to help clear up the diarrhea and get your dog feeling his best again.  For more advice, find out how to help a dog with diarrhea.

3. Loss of appetite


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There’s no NHS for pets. Veterinary care can be eye-wateringly expensive and most pets will need treatment for an illness or injury at some point in their life. It’s difficult to think about your animals being hurt or unwell, but you need to ask yourself: what would you do if you were faced with a vet bill for hundreds or thousands of pounds?

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Some dogs are naturally picky eaters, but others never miss a meal. If your dog suddenly loses interest in the best dog food that he usually wolfs down, it could be a sign that he’s feeling sick. A loss of appetite is even more concerning when it is accompanied by other symptoms such as nausea, fever, lethargy, or pain, all of which can make your dog less inclined to start eating again. The longer your dog goes without eating, the more likely it is that other problems will develop, so it’s important to stay on top of changes in appetite. If your dog has missed more than one or two meals, then it’s time to see your veterinarian for help.  Our article 11 Things to check when your dog is not eating has some further tips to help.

4. Accidents in the house

It’s normal for a new puppy to have a few accidents in the house during the potty training process.  But if a previously well-trained adult suddenly starts urinating or defecating in the house, this is often a sign of a medical problem such as a urinary tract infection, bladder stones, or other underlying illness. Accidents in the house may also be accompanied by other symptoms, such as straining to urinate or blood in the urine. It is particularly important to monitor your pet for signs of urinary blockage, such as straining to urinate without producing any urine, abdominal pain, and lethargy.  If your pet is having urinary symptoms, see your vet right away.  Your vet will likely ask you to bring in a sample of your pet’s urine, which will be evaluated for bacteria, crystals, and other signs of urinary tract disease.  

5. Itching, scratching, and licking

Skin conditions are one of the most common reasons dogs go to the veterinary clinic every year. Frequent scratching, licking, hair loss, and rashes are all signs that your dog may have a problem. While it may be tempting to try to treat your dog’s dermatology issues with over-the-counter products or home remedies, these methods rarely work because they do not address the underlying cause of the itch. Problems like common allergies in dogs, parasites, or skin infections must be appropriately treated by your veterinarian to fully improve, so it’s important to seek medical attention sooner rather than later.  Your veterinarian will perform a full physical examination, and will likely perform some diagnostic testing such as a skin scraping or taking samples of your pet’s skin.  Your pet will likely be sent home with medications such as antibiotics, steroids, allergy medications, or anti-parasitics to help treat the root cause of the itch, which should make him much more comfortable.

is my dog sick

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6. Changes in drinking and urination habits

Does it seem like your dog is constantly thirsty? Or has he started asking to go to the bathroom twice as often? Increased drinking and urination are symptoms of many common medical conditions, including hormonal imbalances like Diabetes Mellitus and Cushing’s Disease. These changes can be subtle, so it’s important to keep an eye out for them, especially in senior dogs that are more prone to developing these types of illnesses.  When it seems like your dog can’t get enough water or needs to go out to the bathroom much more frequently than usual, it’s definitely time for a visit to your veterinarian to get to the bottom of the issue..

7. Pain and decreased mobility

 Just because your dog isn’t crying, doesn’t mean he isn’t in pain.  Signs of pain can be very subtle and may include minor changes like a reluctance to get up, exercise intolerance, limping, hiding, tiring more quickly, or difficulty with certain activities. Although it can be tough to see your pet in pain, never give your dog any over-the-counter medications or human pain medications – many of these are extremely toxic to dogs. Your vet can prescribe a medication for your dog that will safely address the pain and inflammation he is experiencing. Immobility might also be a sign of fading puppy syndrome.

8. Coughing and sneezing

Coughing, sneezing, and changes in breathing are common symptoms of many respiratory conditions. Coughing and heavy breathing can also occur with many types of heart disease. While coughing and sneezing can sometimes be symptoms of a mild upper respiratory infection – not unlike a human catching the common cold – it’s still important to have your dog checked out by a veterinarian to ensure it’s not something more serious.  If possible, try to take a video of your dog’s cough to show your veterinarian.  Different types of cough can point to different medical conditions.  For example, a honking cough when excited may be a sign of a collapsing trachea, while a dry, hacking cough may point to chronic bronchitis.  Since your dog may not cough in the exam room, a video is a great way to help your veterinarian assess your dog’s cough.

9. Bad breath

Bad breath is more than just stinky kisses. Bad breath can be a sign of painful dental disease, esophageal reflux, or digestive upset. Look for other signs such as pawing at the face and mouth, difficulty chewing or swallowing, or copious drooling, which can point to a bigger problem. Although daily brushing, dental chews, and special dental diets can help prevent plaque and tartar from forming, once tartar forms on the teeth the only way to remove it is with a professional dental cleaning under anesthesia.  If your dog has bad breath, he may need professional veterinary dental care to address any diseased teeth and get his mouth smelling fresh again.

10. Changes in behavior

Pain or discomfort can lead dogs to become more irritable, withdrawn, or even aggressive. Some illnesses can also cause neurologic symptoms that can make your pet appear lost, disoriented, or not like himself. Senior dogs can even experience a condition called Canine Cognitive Dysfunction, similar to human senility, in which they may forget some of their training and fail to recognize familiar people.  Any sudden change in your dog’s behavior should be evaluated by your veterinarian. Even if the problem turns out to be mental, rather than medical, your vet can still help you work through the issue to get your dog feeling like his old self again.

How long should I wait until taking my dog to the vet?

You know your dog better than anyone. If you suspect your dog may be sick or injured, it’s best to seek veterinary care right away.  Although it may be tempting to take a “wait and see” approach, this can lead to more serious illness and more costly medical bills down the line!  For your pup’s health and safety, we recommend seeking the advice of a veterinary professional as soon as possible to help get your dog back to his old self.

Is my dog sick or just sad? 

Sometimes it can be hard to tell whether your dog is sick or just sad. Being ‘off color’ or ‘not himself’ are common reasons a dog gets brought to see a vet, but we don’t always find the cause. 

Although dogs do feel emotions, including sadness and or depression, they don’t necessarily show them in the way we humans would. So although you might read their body signals and think ‘that dog looks sad’, that’s not necessarily what they’re feeling. This means we generally recommend you take your dog to the veterinarian for a check up (or at least pay close attention, looking for other symptoms) if they appear to be ‘sad’, as it’s more likely they’re sick. 

One good test is to offer your dog a walk – a bored or sad dog will often cheer up, whereas a lethargic dog won’t – or if they do, they’ll tire quickly. If in doubt, get them checked, as many, many diseases can start with being ‘off color’.  You can also read our expert's advice on How to identify a pet emergency and find out how much does an emergency vet cost?

Elizabeth Racine, DVM

Dr. Elizabeth Racine is a small animal general practice vet covering all things pet health and wellness.  Her special interests include veterinary behavior, nutrition, and internal medicine.  As a freelance writer, Dr. Racine has written content for major companies in the industry such as the American Kennel Club, Merck Animal Health, Bayer PetBasics, Elanco, and CareCredit.  In her free time, Dr. Racine enjoys playing trampoline dodgeball, hiking with her beagle Dasher, and spending time with her three mischievous cats.