How To Tell If My Dog is Sick

Published: 20 Apr 2024
Kathy R. Conner
Kathy R. Conner
Kathy is a licensed veterinary surgeon and writer in Miami. With over 20 years of experience in deal with pets and small animal, she hopes to share her knowledge on what she learned throughout her life to all animal lover. On her free time, she likes to attend Yoga and Meditation classes.
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If you’re a first-time dog owner who tends to be anxious, you may find yourself wondering, “Is something wrong with my dog?” or asking, “How can I tell if my dog is sick?” Even when you have a nagging feeling that something’s off, deciphering your dog’s symptoms of sickness can be confusing.

And if your pup is actually unwell, you can’t even notice the warning signs of illness and any dog symptoms. After all, pets are notorious for hiding them. Because of that, you may feel sad and guilty that you didn’t know your puppy was in pain or hurting.

Here are a couple of signs and situations that can help you puzzle out if your best friend could be sick, things you can do to prevent common dog illness symptoms, and when you should contact your veterinarian. 

8 Signs Your Dog May Be Sick

As is the case with people, a pet’s health changes with age. But no matter the age, your pet can fall ill.  The following are the most common warning signs in which pets tell us they’re feeling under-the-weather.

1. Lack of Appetite

One of the most obvious signs that something is wrong is when your dog suddenly stops eating and drinking. Dogs eat a lot. But if your pet just moves his food around or can no longer finish his food, you should bring him to the vet. 

A change in his drinking habits is also something to keep an eye on. Excessive thirst can indicate that your pet has hormone issues, fever, or kidney problems. Appetite change can be associated with weight loss or gain as well.

2. Vomiting/Throwing Up

Every pet vomits at times. Vomiting can be a sign of a more serious infection or a developing allergy, particularly in older dog breeds. When a pet has these sick dog symptoms, especially a combination with loss of appetite or lethargy, be sure to contact your veterinarian.

Have Your Dog Take Medicine to Maintain Its Health

3. Coughing/Panting/Labored Breathing

Coughing, labored breathing, nasal discharge, panting, and wheezing are all signs of respiratory distress. These issues can extend from a simple cold to dog flu. If your pup has a cold or flu, there will likely be other symptoms present such as a runny nose and redness of the eyes.

A honking noise can mean a more serious tracheal issue which is common among specific dog breeds. Check the color of your pet’s gums and tongue if he is having breathing difficulties. If you notice any bluish tint on your dog’s tongue and gums, then he needs immediate emergency care.

4. Itchy Skin/Sores/Lumps

Physical changes like new bumps and lumps, sudden changes in old lumps, bloody sores, sudden weight loss or gain, persistent itch, and hair loss are often the most noticeable. You know your pooch best. If it’s enough to make you worry and you suspect your dog may be ill, then you may seek a veterinarian’s attention for help.

5. Aggressiveness/Behavioral Changes

When your normally passive dog suddenly turns aggressive towards you, pause to think about why you are observing this behavior from your dog.

Has he been favoring a mark on his body, such as his paw, you touched it and he reacted in defense? Pay close attention to why he is behaving this way and get him checked out if the behavior continues.

Know When Your Pet is in Trouble

6. Diarrhea

If your dog has diarrhea or persistent constipation that lasts longer than 48 hours or there are any differences in the dog’s bathroom habits such as the presence of mucus or blood in his poo, it is advised to visit your vet.

If possible, you could take a fresh stool sample with you. Excessive amounts of urination may also signal adrenal gland, liver, or kidney disease.

7. Lethargy/Whimpering

If for any reason your puppy just isn’t his healthy, normal, energetic self, it’s worth taking the ‘diagnosing sick dog’ look. Pets can just look unwell the way humans do.

Lack of enthusiasm can often be accompanied by fever. If you check and found out that his body temperature is over 104 F or under 99 F (normal is usually 100.5 F to 102.5 F) a trip to the vet is a good idea [1].

8. Noticeable Pain

Unfortunately, most dogs in pain don’t vocalize at all. Your pooch may whine in pain when you go to touch his injured sore back or paw, but it’s even more possible that he will suffer in silence.

Obvious joint swelling, trouble chewing, and trouble getting up from the ground are some signs to watch out for. If anytime there is uncontrolled bleeding or your dog has fallen from a height, seek veterinary care right away.

Things You Can Do to Prevent Common Dog Illnesses

Your vet may recommend preventative care screening as part of your pup’s annual exam since signs of disease are not always evident.

This testing often includes electrolyte and chemistry tests to ensure your pet isn’t dehydrated and to evaluate his internal organ status; tests to detect if your dog may have tick-borne, heartworm, or other infectious diseases; a complete blood count to rule out any blood-related problems; urine tests to screen for urinary tract infection and other kidney-related conditions; a thyroid test; and an ECG to screen for abnormal heart rhythm.

More tests may be added on an individual basis. Your vet will advise the right action for your furry best friend.

Preventive care testing will not only help you identify disease in its earlier stages when it’s most probably to react to treatment but it also can help you avoid risk to your dog’s health if an illness goes undetected and more importantly, refrain from spending significant medical expenses. Screening your pet’s health annually is the best preventative medicine.

Signs of Illness in Dogs to Look Out For

Frequently Asked Questions

How Do Dogs Act When They Are Sick?

When pets don’t feel well or are in pain, they tend to exhibit behavioral changes. These usual personality changes occur all of a sudden. Your normally social pooch may begin to withdraw. Or your kind, healthy, and lively dog may start to display aggression, snippiness, or lethargy.

Should I Take My Dog To A Vet At The First Sign Of Illness?

Yes, you should take your dog to a vet at the first sign of illness especially if you observe signs of labored breathing, collapsing, very pale or blue gums, or loss of consciousness. Your vet will examine your pet, know your dog’s health history, and can make the best course of action and recommendations.

What Does Lethargy Look Like In Dogs?

Often, a lethargic dog is groggy, slower to react to his environment, excessively tired, lacking enthusiasm or energy, uninterested to do his usual, normal activities, doesn’t react at all, and generally out of character. Be on guard to whether or not your dog is just acting out of the norm or just tired and in need of more serious attention.


While some minor issues like fleas can be dealt with at home, the more serious health problems should be dealt with by your vet. Learning about the warning signs can help you figure out your “how to tell if your dog is sick?” question.

Being aware of what action to take can also help you decide the best course of action when your furry pal does start to feel under the weather.

You know your precious dog better than anyone. So even if it’s not easy to find out the illness in your pooch, you’ll have to seek a range of subtle signs that may indicate a potential issue. If you do perceive anything out of the ordinary, don’t rely on websites or books for diagnosis. Contact your veterinarian immediately.

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