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Tierambulatorium Wienerberg

This article was written by TOBALIE in cooperation with Tierambulatorium Wienerberg

Anyone who has ever had a high fever knows how unpleasant and exhausting this feeling can be. Among other things, you feel very weak and low, struggle with headaches and aching limbs, your pulse races and your appetite seems to be blown away. When our beloved dogs are suffering from a fever, they are certainly not doing too well either. Very high fever can even be life-threatening. How you can recognise a fever in your dog, which symptoms he shows and how you can support your darling, you can read in the following lines.

What is fever?

First of all, the good news: fever, also known as pyrexia in medicine, is not a disease in its own right. A fever is always a symptom, a defence reaction of the body. An increased temperature or fever supports the immune system in fighting various pathogens and co. The level and duration of the fever are sometimes dependent on the type and number of pathogens, or on the severity of the illness. 

Good to know: If your dog has a fever, there is not always reason to panic. A healthy (dog’s) body can usually cope well with a short, moderate fever. Since fever supports the immune system, it is not always advisable to take immediate countermeasures such as fever-reducing medication. However, this should be clarified by a veterinarian, as we are usually not able to judge when medical support is necessary.

From when does the dog have a fever?

The normal body temperature of dogs is between 38 degrees and 39 degrees, puppies up to 39.5 degrees Celsius. Compared to us humans (36 degrees to 37 degrees Celsius), this is significantly higher. Fever starts at 39°-40°. From a value of over 41 degrees Celsius, fever in dogs can assume life-threatening proportions. 

The duration of the fever determines how the fever is categorised:

  • Ephemeral fever: Usually lasts only one day.
  • Acute fever: Up to 2 weeks.
  • Subacute fever: 2 to 3 weeks.
  • Chronic fever: From 3 weeks. 

Fever can also rise (or fall) continuously or occur in episodes. Between the relapses, there is usually a so-called recurrent phase. During this phase, the patient on four paws is usually free of fever. 

Good to know: Your dog’s body temperature can also rise during intensive physical activity and when the outside temperature is very high. However, this is only slight and only for a short period of time. 

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What are the causes of fever in dogs?

A fever is a natural defence process of the immune system and is usually harmless for a healthy dog. However, a fever is an indication that certain processes are taking place in your dog’s body, which in turn require further clarification. Especially if your dog shows other symptoms of an illness (see below).

Unfortunately, it is usually impossible for us as laypeople to determine what the causes are, as the range of possibilities for why the dog has a fever is very broad:

  • Infections with viruses
  • Infections with bacteria
  • Parasite infestation
  • Fungal infections
  • Poisons, chemicals
  • Inflammations 
  • Immune-related diseases such as rheumatism or arthritis
  • As a vaccination reaction (usually only brief and mild)
  • Side effect of medication, radiation therapy
  • Result of injuries (wound fever)
  • Heat stroke
  • Tumours
  • And more

How do I recognise a fever in a dog?

How can I find out if my dog has a fever? Obviously, when you think of fever, you automatically think of a clinical thermometer. This is of course the first choice when it comes to taking your dog’s temperature. The measurement is usually taken rectally (insertion into the anus) with a digital thermometer. Please use a special thermometer for dogs.

However, fever in dogs can also be recognised by other signs, as it usually does not occur alone, but is usually accompanied by other symptoms: 

  • The dog appears altered in its behaviour and usually shows a disturbed general condition. 
  • Seems apathetic, depressed, restless and lazy.
  • Increased need for sleep, need for closeness or distance.
  • Shivering.
  • The dog’s nose feels dry
  • In addition, the dog’s nose, as well as the ears and the abdominal region, feel very warm.
  • Warm, dry, intensely reddish gums may also be an indication.
  • Altered appetite: Usually loss of appetite.
  • The bowel activity decreases: A so-called “fever faeces” may appear. This is usually very dry and hard. Diarrhoea is also possible. 
  • Loss of fluids and increased need to drink.
  • The pulse increases.
  • Breathing becomes faster.
  • Increased panting, whimpering.

When should I visit the doctor?

When in doubt, always. If the following conditions apply to your faithful companion, you should lose no time and visit a veterinary clinic or similar as soon as possible: 

  • Fever over 40 degrees Celsius
  • Long-lasting fever (longer than 3 days)
  • In puppies or older animals
  • In weakened and/or previously ill animals
  • Apathetic states
  • Pain
  • Severe trembling, severe shivering

A high fever is extremely strenuous for the small dog’s body. The circulation is working at full speed, the organs are under great strain, the dog tends to become dehydrated and in extreme cases the body’s own proteins are destroyed. 

Attention: If your dog is not feeling well and you notice that he is ill, please seek the advice of a veterinarian. They will be able to assess whether an examination or treatment is necessary.

What to do if your dog has a fever?

One thing is certain: as a loving owner, you quickly feel sorry for your dog when he or she is visibly unwell. It is absolutely understandable that you then pull out all the stops as quickly as possible to ensure that your beloved furry friend is well again as soon as possible. 

In any case, it is always advisable to consult a veterinarian, especially if one of the points listed in the last paragraph applies to your dog. You should also waste no time if your feverish friend’s condition continues to deteriorate. Of course, this also applies to healthy and robust dogs.

A short, mild fever is usually not dangerous. After consulting your vet, you can help your pet with the following tips:

  • Your darling needs a lot of rest now: Make sure that your dog is not exposed to any great exertion and offer him a place to withdraw.
  • Walks should be limited to the essentials. 
  • Make sure your dog has enough water. Adequate water drinking is very important now.
  • If your dog doesn’t like to eat, you can try offering him unsalted meat or vegetable broth.
  • Make sure the sleeping area is cool and dark. 
  • Damp, cool compresses around the paws can help.
  • Please never try to treat your dog on your own with medicines from your medicine cabinet!
  • Take the temperature at regular intervals.


A fever is a natural reaction of the immune system to mobilise the body’s defences. The increased temperature effectively fights off pathogens and the like. A low fever in previously healthy adult dogs usually disappears by itself and only requires (after veterinary consultation) a lot of rest and sufficient water intake. If the dog’s health deteriorates or certain risk factors are added, a visit to a veterinary clinic is essential.