how do i know if my dog has a fever

How do I know if my dog has a fever?

Watching over the health of your dog also means knowing how to detect changes in his behavior that could result from a health problem. How do i know if my dog has a fever? Lack of appetite, weakness, listlessness, tremors … are potentially all signs that your dog has a fever, which can be caused by a viral, bacterial or parasitic infection.

But from what threshold is a dog considered to have fever? What are the possible causes of an increase in the dog’s body temperature? Should we be worried? How to react in case of dog fever?

What is a dog’s normal body temperature?

At birth, a puppy’s body temperature is around 35°C. It gradually increases during his first weeks of life, to stabilize at the age of one month at around 38.5°C, a temperature considered normal for a healthy adult dog.

This average temperature is however subject to variations, depending on various factors.

First of all, it depends on the outside temperature. This is because the body temperature of a healthy dog tends to vary according to outdoor conditions.

dog's normal body temperature

It is also influenced by his level of activity. Like what we also see in humans, it is normal for a dog to see its temperature increase during a more intense physical effort.

Conversely, a bitch in heat or in the process of giving birth sees her body temperature decrease, to an average of 37.4°C.

Finally, it is common for the temperature of a puppy or even an adult dog to rise following vaccination.

All of these fluctuations are perfectly normal and should not be of particular concern.

How do i know if my dog has a fever? Thresholds to keep in mind

Except in special circumstances, the body temperature of an adult dog varies between 38°C and 39°C.

If it drops below 38°C, we speak of hypothermia. An abnormally low temperature may be due to a disease (diabetes, heart failure, etc.) or a result of prolonged exposure of the animal to cold conditions. If it drops below 36°C, his condition is serious, it is an emergency situation and there is no time to waste.

On the other hand, a dog’s body temperature can exceed the normal level of 39°C. It is a phenomenon of hyperthermia, more commonly called “fever”. Fever is an immune reaction that is triggered when the body has to deal with an attack from a foreign body such as allergenic agent, virus, bacteria … That said, hyperthermia can also simply be the consequence of a stroke.

Possible causes of fever in dogs

In any case, if your canine companion’s temperature reaches or even exceeds 41.5°C, his life is in danger and you must then react as quickly as possible.

Possible causes of fever in dogs

Apart from the physiological variations mentioned above, a significant and persistent increase or decrease in the temperature of your companion may be synonymous with a dysfunction or a pathology requiring veterinary intervention.

The most common causes of fever in dogs are:

A parasite

The number one enemy of dogs, a tick can inoculate the animal with serious diseases such as piroplasmosis, borreliosis (Lyme disease) or even ehrlichiosis. They are manifested by fever, digestive disorders and a lack of appetite.

When a dog is carrying ticks, it is best to immediately consult the veterinarian as there is a risk of a rapid deterioration of his condition with irreparable consequences.

An infection

The fever can be the consequence of a localized infectious disease (gastroenteritis, urinary infection, bronchitis) or generalized (tetanus, leptospirosis, toxoplasmosis).

A virus

Fever can be one of the manifestations of a viral pathology such as distemper, kennel cough, parvovirus or even rabies.

Only the veterinarian is able to make a diagnosis and offer treatment adapted to the illness your canine friend is suffering from.

A tumor

The fever can reveal the presence of a tumor, a condition referred to as malignant hyperthermia.

dog heat stroke

Heat stroke

The risk of heat stroke for the dog is great when he is exposed to hot and poorly ventilated conditions (car, kennel, etc.). Such heat stroke can raise his temperature to critical thresholds of 41°C or 42°C, that can be fatal.

It is worth noting that brachycephalic dog breeds (Pekingese, Pug, Bulldog, etc.) are more sensitive to heat, and can be the victims of a stroke much more easily than the average dog.

Whether you walk your dog on the street, at the beach, by the pool or even just in the garden, make sure that your companion is not exposed to the sun for too long, and make sure that he always has of fresh water available, to prevent the risk of dehydration. If he does not seem to take a great interest in his water bowl, do not hesitate to encourage him with a treat.

How to take your dog’s temperature?

How do i know if my dog has a fever? Contrary to popular belief, the dog’s nose is not a reliable temperature indicator. A feverish dog may well have a cool, wet nose, suggesting that he is in good health. Taking your dog’s temperature is the safest way to determine if he actually has a fever, and if so, to know how high his temperature is.


Although it may be tempting, because it is less restrictive for you and for him, to use a forehead thermometer or an infrared thermometer to take your dog’s temperature, it is best to avoid these devices, because the hair thickness is likely to distort the results. This is obviously especially true with long-haired dog breeds.

The rectal temperature being the most reliable, an anal thermometer is really the best way to measure your dog’s body temperature. To make the measurement in the best conditions, certain rules must be observed:

Choose the right thermometer

Choose a flexible thermometer with digital display, to facilitate the process and reading the result. Also make sure that the result is displayed quickly, to prevent your dog from getting too impatient during the operation.

how to know if dog has fever

Get assistance

Do not hesitate to seek the help of a third person to hold your dog’s tail while you take his temperature

Moisten the thermometer

For better comfort, remember to moisten the thermometer tip with water or lubricate it with petroleum jelly (recommended) before gently inserting it into his anus.

Set up in a quiet environment

Even though it is completely harmless, this intrusive act is quite unpleasant for your dog. It is therefore important to practice it in a calm environment and to reassure him throughout the process.

In case of doubt or difficulty in taking the dog’s temperature, it is advisable to seek help from a veterinarian.

How do I know if my dog has a fever? Other known symptoms

Most of the time, febrile syndrome is not just about an increase in the dog’s body temperature. Thus, depending on the case, different symptoms can accompany the fever such as vomiting, diarrhea, inappetence, restlessness, tremors, fatigue, weakness or even apathy, increased heart rate, cough and nasal discharge.

If you observe one or more of these symptoms, your first instinct should be to take the dog’s temperature. It will be a valuable clue to help the veterinarian make a diagnosis.

take your dog's temperature

What if my dog has a fever?

If your dog has a fever but his general condition is good (he is feeding properly, showing no signs of weakness or difficulty in breathing), it may be a fleeting phenomenon. If so, it is likely that his temperature will drop on its own after a few hours. You must nevertheless remain attentive, by regularly monitoring his temperature and behavior. If his temperature rises or if other symptoms appear, a consultation with the veterinarian is required.

In other cases, the fever is accompanied by signs that support an emergency intervention.

In the event of heat stroke, the dog salivates excessively and/or has difficulty breathing. It is then necessary to immediately move him to a cool and ventilated place and apply wet cold towels on him to try to lower his temperature a little. He must then be taken quickly to the veterinarian, who will take measures to avoid cerebral edema, which is potentially fatal.

In the case of an infectious disease, the dog is weak and/or depressed. It is then advisable to apply damp towels on his body, then dry him and to encourage him to drink by regularly offering him water or vegetable broth. If, however, the fever persists for more than 24 hours or approaches or even exceeds 41°C, it becomes necessary to take him to the veterinarian.

The veterinarian will probably take a blood test to identify the cause of the infection and therefore establish an adequate treatment. He may also have to carry out additional examinations (ultrasound, X-ray, urinary examination, etc.) to rule out certain causes or, on the contrary, to confirm them.

How do I know if my dog has a fever? A word of caution

In any case, you should never give your dog any medication without consulting the veterinarian beforehand. In particular, it should be remembered that certain analgesics or anti-inflammatory drugs intended for men (paracetamol, ibuprofen, aspirin, etc.) turn out to be real poisons for dogs.

While most infections are easily treated, it is important to have the right reflexes and take the dog to the vet when necessary, rather than letting the fever persist and taking the risk of seeing his condition deteriorate.


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